Keywords: Psychiatric Disorders, Adolescents, depression, emotional regulation, PFC

Motivation: The neural correlation between emotional regulation and  adolescent depressive symptoms has not yet been elucidated.

Goal(s): Our goal was to identify the neural substrates of emotional regulation ability (ERA) and its association with depressive symptoms in adolescents.

Approach: We conducted whole-brain correlation, prediction and mediate analyses with resting-state fMRI and behavioral measurements data.

Results: The results indicated that ERA was associated with brain activity in right ventromedial prefrontal cortex (VMPFC) and cuneus. Additionally, ERA mediated the link between spontaneous activity of VMPFC and depressive symptoms.

Impact: Emotional regulation ability may indirectly modulate depressive symptoms in adolescents through affecting neural activity in the VMPFC, which may provide some neurobiological implications for early intervention of adolescent depression.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: Compared to cortical regions, the involvement of  functional connectivity of subcortical regions in bipolar disorder (BD) are less well known.

Goal(s): The potential involvement of subcortical and subregions of thalamus are explored in BD.

Approach: Seed-based subcortical and thalamic subregional functional connectivity was compared between the BD patients and HCs, as well as between patients with BD type I (BD-I) subgroup and HCs as a sub-group analysis.

Results: BD patients showed increased functional connectivity between left thalamus and right lingual gyrus, between right anterior thalamus and superior frontal gyrus, and between right ventral anterior thalamus and precuneus.

Impact: These findings provide evidence of disorganized thalamo-cortical functional connectivity in BD, suggesting that the thalamus and its subregions may play important and specific roles in the neural circuitry of BD.

Keywords: Psychiatric Disorders, Diffusion/other diffusion imaging techniques, schizophrenia

Motivation: Schizophrenia is a complex psychiatric disorder with cognitive and behavioral disruptions. Previous studies have reported the abnormalities of white matter, but elucidating the biological mechanisms remains a challenge.

Goal(s): To investigate the changes of white matter in schizophrenia patients and correlate with changes of neuropsychological function.

Approach: NODDI was adopted to quantify the changes of neurite orientation and extracellular free water in white matter among schizophrenia patients. The correlation analyses between image indices and neuropsychological scale scores were performed.

Results: Significant changes of brain microstructure, particularly in the fornix with schizophrenia, was observed. Those changes were correlated with global function and cognition decline.

Impact: This study demonstrated abnormalities of white matter microstructure, especially in the fornix, among individuals with schizophrenia. NODDI could become a potential technique for finding biomarker in revealing the pathophysiological process of the disorder.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: Impaired global cerebrovascular reactivity (CVR) has been reported in major depressive disorder (MDD). However, regional CVR has not been evaluated in MDD patients due to experimental difficulties. 

Goal(s): The goal is to use a recently developed resting-state technique to map regional CVR in MDD patients. 

Approach: Resting-state images was filtered and relative CVR index was calculated by regressing the voxel-wise BOLD signal against the reference signal. 

Results: CVR was significantly reduced in occipital lobe in MDD. Temporal CVR was negatively correlated with illness duration, while psychomotor retardation was associated with elevated CVR in several emotion-related areas, including amygdala. 

Impact: Current study indicated a region-specific relationship between cerebrovascular dysfunction and depression.

Keywords: Psychiatric Disorders, Spectroscopy

Motivation: There is limited information on anterior cingulate cortex (ACC) myo-inositol (m)I level in medication-free bipolar disorder (BD) patients in depressed state, which can explore role of neuro-inflammation in BD.

Goal(s): Investigate modulation of ACC mI level during Li monotherapy.

Approach: Patients with BD (depressed state) and healthy controls were scanned at 7-tesla MRI with a semi-LASER sequence at baseline and 2, 8 and 26 weeks from onset of Li monotherapy, and ACC mI level was measured at each time point.

Results: mI level decreased in 1st 2 weeks of onset of therapy but the reduction was not observed after 8 weeks.

Impact: The preliminary results suggest that decrease in neuro-inflammatory/microglial marker mI during Li monotherapy of depressed BD may be a short term effect. Future studies can investigate if this is specific to depressed state by investigating during manic state also.

Keywords: Psychiatric Disorders, Psychiatric Disorders, Schizophrenia, Subtypes, MRI, fMRI, Machine Learning

Motivation: The heterogeneity in schizophrenia remains poorly understood which contributes to the limited success of existing treatments and the observed variability in treatment responses.

Goal(s): Our goal was to classify schizophrenia and its subtypes by using machine learning (ML) and MRI to improve understanding of the neurological basis of this schizophrenia.

Approach: We applied conventional ML and feature selection methods on MRI to reach our goal.

Results: We were able to distinguish schizophrenia and healthy and subtypes of schizophrenia using the combination of MRI and ML. we also showed evidences of brain dysfunctions in schizophrenia and its correlation with behaviors related to the disorder

Impact: The outcomes of this study reinforce the notion that the fusion of machine learning methodologies with structural and functional neuroimaging holds the potential to unearth novel biomarkers, consequently contributing to the enhancement of diagnosis and treatment strategies for psychiatric disorders.

Keywords: Psychiatric Disorders, Metabolism

Motivation: To better understand the neurochemical correlates of cognitive impairment in subjects with schizophrenia and healthy control subjects. 

Goal(s): Are regional brain metabolite levels and peripheral markers correlated with cognition in subjects with schizophrenia?

Approach: Regional brain metabolism using 7T MRS, detailed neuropsychological testing, and peripheral markers from venipuncture were obtained in 12 subjects with schizophrenia and 9 healthy control subjects. 

Results: In all subjects, significant positive correlations were found between regional glutamine (Gln) levels and blood ammonia levels, and, in subjects with schizophrenia, regional brain Gln levels were negatively correlated with measures of cognition. 

Impact: These preliminary data support the hypothesized role of aberrant Gln metabolism as one of the factors associated with CI in schizophrenia, possibly by perturbation of the glutamate/GABA-glutamine neurotransmitter cycle.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: Assessing the Gray matter volume changes in the hippocampal subfield and amygdala nuclei will help to understand the underlying mechanisms of the disease. 

Goal(s): To assess hippocampal subfield and amygdala nuclei volume changes in patients with early-onset schizophrenia (EOS).

Approach: High-resolution 3D T1 images were acquired in both the control (34) and the EOS (31). Hippocampal subfield and amygdala nuclei segmentation was performed using FreeSurfer.

Results: Volume reduction in the bilateral basal, para-laminar, and right lateral amygdala nuclei, as well as molecular layer, subiculum, para-subiculum, CA4 hippocampal subfield.

Impact: The gray matter volume reduction of the hippocampus subfield and amygdala nuclei maybe associated with poor clinical outcomes in EOS.

Keywords: Psychiatric Disorders, Psychiatric Disorders, fMRI (resting state)

Motivation: Given that suicidal ideation (SI) is closely related to social development, it is important to understand the associations between network function and SI (or the non-suicidal ideation, NS) in patients with depression.

Goal(s): We aim to investigate brain function changes in depressed patients with SI and NS between baseline (Time 1, TP1) and follow-up (Time 2, TP2; after one year of therapy).

Approach: Paired t-tests, repeated-measure ANCOVA, and network-based statistical analysis were used.

Results: We found differences in functional activity after treatment, the results surrounded the DMN region in each group. NBS revealed significantly increased functional interconnections of subnetworks after treatment.

Impact: Our findings provide more information about potential neural biomarkers of various depressive disorders.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: To investigate the specific changes of volumetric differences in Major Depressive Disorder (MDD) and healthy controls (HC) including their relationships with clinically related behavioral phenomena.
 

Goal(s): To investigate volumetric differences in the thalamic subnuclei of untreated MDD patients and HC groups.

Approach: We collected high-resolution 3D T1-weighted images from untreated MDD patients and age- and sex-matched healthy controls.

Results: No significant volume differences of the bilateral thalamus as a subnuclei between MDD patients and healthy controls. Found age-by-diagnosis interactions for specific thalamic subnuclei. Partial correlation analyses show several left thalamic subnuclei showed positive correlations with HAMD-17 scores and cognitive disturbance scores.

Impact: The study offers valuable insights into thalamic subnuclei changes and their impact on MDD. These findings underscore the significance of examining specific thalamic subnuclei and their potential impact on MDD's development.

Keywords: Psychiatric Disorders, fMRI (resting state), anxiety disorders

Motivation: It is necessary to clarify the neurobiological mechanisms of anxiety disorders (ADs) to provide a unique biomarker for diagnosing ADs, facilitating accurate clinical diagnosis and targeted therapeutic interventions.

Goal(s): The primary objective is to elucidate the specific abnormalities in individuals with ADs' amygdala-based whole-brain connectivity.

Approach: The coordinate-based meta-analysis was conducted to find amygdala resting-state functional connectivity in patients with ADs. Furthermore, subgroup analysis was performed to explore potential functional lateralization.

Results: Distinct functional connectivity abnormalities were found in ADs, which provides a reference for diagnosing ADs.
 

Impact: These findings not only enhance our understanding of the underlying pathophysiological mechanisms in ADs but also may be valuable for the prevention, diagnosis and intervention of ADs.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: It is currently unknown which hippocampal substructure or composite based on the different is the most effective in evaluating treatment outcomes.

Goal(s): To explore which hippocampal organization might predict an early antidepressant response to in patients with major depressive disorder.

Approach: We used Freesurfer software to segment the hippocampus automatically, and created the hippocampal composites by summing component substructures early antidepressants response were evaluated from many dimensions of hippocampal organization.

Results: We found hippocampal substructures segmented along its transverse axis exhibit best classification performance, and the most relevant region for treatments efficacy maybe located in the CA1 and ML. 

Impact: We found hippocampal substructures segmented along its transverse axis exhibit best classification performance, and the most relevant region for treatments efficacy maybe located in the CA1 and ML. 

Keywords: Psychiatric Disorders, Psychiatric Disorders, Schizophrenia, Glymphatic, Perivascular Space, water clearance

Motivation: Perivascular spaces(PVS) are fluid-filled spaces that surround blood vessels in the brain. While dilated PVS(dPVS) play an important role, investigations into dPVS in schizophrenia are poorly understood.

Goal(s): In this study, we aim to explore the potential of dPVS quantification as a biomarker for schizophrenia.

Approach: For volumetric assessment, we segmented the dPVS in the white matter(WM) and basal ganglia(BG), and calculated the volumes and numbers of dPVS for each subject.

Results: Our findings reveal differences in dPVS numbers and volumes among schizophrenia subgroups, especially in treatment-resistant schizophrenia(TRS) which showed smaller dPVS volumes compared to other groups in both WM and BG.

Impact: Our study offers insights into the potential of dPVS quantification as a biomarker for schizophrenia. We observed differences in total dPVS volumes and number of dPVS components between different schizophrenia subgroups and found significant results especially in TRS.

Keywords: Psychiatric Disorders, Psychiatric Disorders, Schizophrenia, Dynamic Functional Connectivity, Cerebellum

Motivation: The complex nature of schizophrenia and its unclear pathophysiology drive our research. We aim to delve into altered brain communication, especially the cerebellum, during transitions between mental states for deeper insights. 

Goal(s): Our goal was to investigate cerebellar communication dynamics in schizophrenia to better understand its pathophysiology.

Approach: We used dynamic ICA analysis to study resting-state cerebello-cortical temporal dynamics.

Results: We observed implications in the dynamics of the cerebello-frontal and cerebello-occipital connections potentially indicative of higher social sensitivity and deficits in cognitive inhibition, and highlighting the role of the cerebellum as modulator between different brain circuits.

Impact: The identification of resting state temporal dynamic changes in cerebello-frontal and cerebello-occipital circuits in schizophrenia provides crucial pathophysiological insights, inspiring further research on the role of the cerebellum as a brain circuit modulator, promising advancements in treatment strategies and outcomes.

Keywords: Psychiatric Disorders, Psychiatric Disorders, schizophrenia, multilayer network analysis, switching rate, antipsychotics, dynamic functional connectivity

Motivation: Although aberrant static functional connectome in schizophrenia has been reported, little is known about how the neural dynamics change in first-episode schizophrenia and are modulated by antipsychotic treatment.

Goal(s): We aim to characterize dynamic topological reconfiguration of brain connectome in schizophrenia.

Approach: Multilayer network analysis was applied to calculate the network switching rates between brain states. We compared switching rates of patients and controls at baseline, and tested for changes after one-year of treatment.

Results: Significantly increased network switching rates were found in patients at baseline, mainly in the sensorimotor and dorsal attention networks. Switching rates were reduced after treatment.

Impact: The findings of excessive neural flexibility in patients extend our understanding for the disease-related brain dynamics aberrance in schizophrenia, and the normalization of network switching rates further illustrate the biological mechanism underlying antipsychotic treatment from a perspective of neural dynamics.

Keywords: Psychiatric Disorders, Brain Connectivity, AUD, withdrawal, diffusion, microstructure

Motivation: Alcohol use disorder (AUD) is a widely spread disorder responsible for 6% of global mortality. Alcohol affects a substantial portion of the population in various aspects and part of these changes may be related to brain modifications.

Goal(s): To identify the effects of alcohol withdrawal on the brain and their link with symptom improvement.

Approach: Combination of connectivity matrices and microstructural models based on diffusion MRI tested during withdrawal period.

Results: The study of global brain connectivity revealed six connections, four of which also showed microstructure changes during withdrawal that were beneficial for recovery in areas heavily affected by increased alcohol consumption.

Impact: We presented an exploratory way to evaluate the effects of short-term withdrawal using connectivity and microstructural models based on diffusion MRI. It revealed four brain connections that deserve to be studied in greater depth in the case of this pathology.

Keywords: Psychiatric Disorders, Brain, Post-traumatic Stress Disorder

Motivation: Neurochemical alterations in PTSD are well-researched across various brain regions, yet understanding their connection to symptoms remains unexplored. 

Goal(s): Our aim was to determine the association between the neurochemical profile and emotional/cognitive symptoms in diagnosed PTSD individuals and healthy controls.

Approach: Participants underwent an MRS scan and CNS Vital Signs survey. Correlations between metabolites and survey scores were examined.

Results: We found significant differences across several PTSD symptoms, for which the severity correlated with metabolite levels alterations in the ACC and hippocampus.

Impact: By understanding correlation between neurochemical alternations and clinical symptom severity, this study provides valuable insights into the pathways of PTSD. It paves the way for innovative approaches in managing neurological disorders.

Keywords: Psychiatric Disorders, Metabolism, Brain, Glutamate, GABA, Addiction

Motivation: Nicotine addiction is a neuropsychiatric disorder with worldwide deaths. Nicotine affects dopaminergic system. However, the dose dependent effect of nicotine on neurometabolic activity is not clear.

Goal(s): To evaluate the impact of dose dependence of acute nicotine on the metabolic activity of glutamatergic and GABAergic neurons in the prefrontal cortex in mice.

Approach: Different acute subcutaneous doses of nicotine were given to mice. Prefrontal cortex extracts were analysed by ¹H-[¹³C]-NMR spectroscopy to quantify ¹³C labelled amino acids and rate of glucose oxidation in neurons.

Results: Nicotine at low dose has excitatory but at high doses has inhibitory effect on neuronal activity in mice.

Impact: Our data shows that nicotine at 0.025 mg/kg increases metabolic activity of glutamatergic neurons but at 1.0 and 2.0 mg/kg decreases. Additionally, nicotine at 1.0 and 2.0 mg/kg suppresses metabolic activity of GABAergic neurons.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: To uncover the neuropathological changes that influence the persistence and progression of symptoms in individuals with chronic Post-Traumatic Stress Disorder (PTSD), particularly among World Trade Center (WTC) responders.

Goal(s): The goal is to identify and characterize the neuroanatomical differences associated with chronic PTSD in World Trade Center responders using diffusion tensor neuroimaging and graph theory techniques.

Approach: employing graph theory to examine network alterations using brain diffusion images.

Results: The results of the study indicated significant differences in the neuroanatomical distances between white matter nodes—measured by weighted characteristic path lengths (CPL)—in World Trade Center responders with chronic PTSD compared to those without PTSD.

Impact: The impact of this study lies in advancing the understanding of PTSD as a disorder with anatomical basis. The association of increased characteristic path lengths with PTSD suggests that the disorder might involve diminished efficiency in the brain's communication networks.

Keywords: Psychiatric Disorders, Neuroscience

Motivation: The structural alterations of hypothalamic subunits involved in the pathophysiology of anorexia nervosa (AN) and bulimia nervosa (BN) remain undetermined.

Goal(s): To investigate the common and distinct alterations in the volumes and structural covariance networks (SCN) of hypothalamic subunits between AN and BN.

Approach: The MRI data were subsegmented and underwent multistage quality control using FreeSurfer, in conjunction with MANCOVA and graph theory analysis.

Results: Larger volumes in the right a-iHyp were  found in BN, smaller volumes in the left infTub and right supTub were  found in AN, compared to HCs. Global efficacy and characteristic path length altered in AN relative to BN.

Impact: We depict distinct alterations of hypothalamic subunits involved in the pathophysiology of AN and BN. These findings provide novel insight into the role of the hypothalamus in both AN and BN.

Keywords: Psychiatric Disorders, Neuroscience

Motivation:  The effects of stimulant treatment (e.g. methylphenidate) on the brain’s dopamine system remain unclear. While animal studies and short-term human trials suggest potential lasting impacts, a comprehensive understanding is lacking.

Goal(s): This study aimed to investigate the persistent effects of stimulant treatment on the dopamine system.

Approach: Using data from a naturalistic follow-up of an ADHD trial, we examined the cerebral blood flow (CBF) response to methylphenidate as a proxy for dopamine function. 

Results: Our findings reveal age-dependent effects. Specifically, we observed a negative association between medication use and CBF response in adolescents, while such an association was absent in adults.

Impact: We found an association between patterns of stimulant treatment for ADHD and the cerebral blood flow response to a dopamine-challenge in adolescents, but not adults. This suggests potential for personalization of stimulant treatment approaches for adolescents with ADHD.

Keywords: Psychiatric Disorders, Brain, Obesity, Anorexia Nervosa, quantitative T1

Motivation: The key structure for maintaining energy balance is the hypothalamus (HT), a small structure organized in multiple nuclei difficult to individualize with MR imaging.

Goal(s): To study in vivo the modulation in Obesity and Anorexia Nervosa of morphometry and microstructure of HT nuclei involved in food networks.

Approach: Characterization of T1 and volumes of HT nuclei (Neudorfer atlas) of 28 young women (13 Controls, 7 AN, 8O) using 3D-MP2RAGE 7T MRI.

Results: Differences in T1 values and volumes were observed in Obese and AN in HT nuclei involved in food networks (bilateral AN, left PVN)

Impact: Quantitative high resolution T1 MRI at 7T allows to characterize the morpho-structural modulation of HT nuclei involved in food networks in obesity and AN. These biomarkers may have a crucial role to monitor adaptation of food networks during therapeutic interventions.

Keywords: Psychiatric Disorders, High-Field MRI, Major Depression, Body Mass Index, Gray/White Matter Ratio

Motivation: Better understand the relationship between depression, obesity and the brain.

Goal(s): Investigate the relationship between body mass index and brain gray and white matter volumes using high-resolution 7T MRI in a population of healthy controls and major depression patients.

Approach: T1-weighted MRI was obtained at 7T and segmented using FreeSurfer. 44 MDD patients and 47 healthy controls of comparable age and body mass index (BMI) were scanned.

Results: BMI showed significant positive correlation with white matter volume and negative correlation between gray matter volume and gray/white ratios in healthy controls and combined cohorts. Similar, though non-significant trends were observed in MDD patients.

Impact: The presented study is the first to ultrahigh field MRI to detect significant correlations between BMI and gray/white matter brain volumes. Differences in these correlations were observed between MDD patients and healthy controls.

Keywords: Psychiatric Disorders, Psychiatric Disorders

Motivation: Trauma can lead to plastic alterations to regional cortical intrinsic activity, and dysregulation in a normal adaption to stress could contribute to PTSD. However, few previous studies disentangled trauma-related adaptation and maladaptation related to PTSD in regional cortical intrinsic activity.

Goal(s): To disentangle trauma-related and PTSD-related abnormalities in regional cortical intrinsic activity.

Approach: We compared the (fraction) amplitude of low frequency fluctuations and regional homogeneity among PTSD patients, traumatized and non-traumatized subjects.

Results: In all trauma-related results, we found decreased (f)ALFF in the bilateral cerebellum, inferior temporal gyrus and middle occipital gyrus was also PTSD-related. 

Impact: We disentangled the distinction between trauma-related and PTSD specific alteration as measured by regional cortical intrinsic activity. It suggested trauma may cause decreased (f)ALFF in cerebellum, however, severe dysfunction exceeding individul’ capabilities to cope with stress may lead to PTSD.

Keywords: Psychiatric Disorders, fMRI (resting state), Methamphetamine, Independent component analysis, Functional network connectivity

Motivation:  There are limited researches on functional network connectivity related to methamphetamine (MA), with existing studies predominantly focused on MA abstainers and lacking studies on the MA dependence.

Goal(s): This study aims to investigate the alterations in functional connectivity within and between resting-state networks (RSNs) in MA-dependence.

Approach: Using independent component analysis to acquire RSNs, calculate FCs within and between RSNs, and perform group comparison and correlation analysis.

Results: The MA group presented not only decreased rs-FC within the cerebellar network, but abnormal inter-networks rs-FC, especially between the cerebellar network and multiple cerebral networks, which is also associated with the severity of psychotic symptoms.

Impact: The cerebellar network of MA dependent individuals needs to be emphasized in future studies.

Keywords: Psychiatric Disorders, Brain Connectivity, Methamphetamine addiction, Resting-state functional connectivity, Effect connectivity, Dorsal raphe nucleus, Ventral tegmental area, Graph theory

Motivation: This study aims to investigate the role of the dorsal raphe nucleus (DRN) and the ventral tegmental area (VTA) in the mechanism of methamphetamine (MA) induced nerve injury.

Goal(s): To further explore the neural mechanism of MA addiction.

Approach: Analyze the functional connections, effect connections, and graph theory analysis between DRN and VTA with other brain regions.

Results: MA-dependent patients showed enhanced FC between the DRN and multiple brain regions in the whole brain. Topological analysis showed that multiple topological attributes of the dorsal raphe nucleus were abnormal.

Impact: Aberrations in the connecome of the dorsal raphe nucleus among individuals with methamphetamine dependence may provide novel insights into the neural mechanisms underpinning addiction to this substance

Keywords: Psychiatric Disorders, Neuro, Morphometric similarity

Motivation: Chronic Insomnia Disorder (CID) influences various levels of brain organization, spanning macroscopic structures to microscopic genomics, the connection between genomic variations and structural brain alterations in CID was not clear.

Goal(s): This study analyzed structural brain alterations-related genomes in CID.

Approach: Using and morphometric similarity (MS) and imaging-transcription alanalysis

Results: The study identified MS reductions in the parietal and limbic regions, as well as enhancements in the temporal and frontal regions in CID patients. The study also discovered spatial correlations between MS alterations and genes associated with excitatory and inhibitory neurons, as well as genes implicated in chronic neuroinflammation processes.

Impact: This study bridges the gap between cortical structural changes and the molecular mechanisms in Chronic Insomnia Disorder (CID), shedding light on the genetic basis and brain alterations associated with CID.  

Keywords: Psychiatric Disorders, White Matter

Motivation: Subthreshold depression (SD) is a significant risk indicator of major depressive episodes. The inhomogeneous magnetization transfer (ihMT) technique has not been used to probe myelin abnormalities and its response to bright light therapy (BLT) in SD.

Goal(s): In this study, we used ihMT technique to investigate myelin integrity in a relatively large sample size of university students with SD.

Approach: The qihMT and ihMTR values of 50 white matter (WM) fibers were compared between SD and HCs.

Results: Macromolecular disruption of myelin in the posterior thalamic radiation (PTR), sagittal stratum, and uncinate fasciculus might exist in the early stages of depression.

Impact: These findings suggest the  myelin impairments in the posterior thalamic radiation could be reversed by bright light therapy, which might be used as the potential neural target for bright light therapy in subthreshold depression.

Keywords: fMRI Analysis, Quantitative Susceptibility mapping

Motivation: Abnormalities in cerebral oxygen metabolism can occur in many brain disorders.  Cerebral venous oxygen saturation (CS_VO₂) allows the assessment of cerebral oxygen metabolism in patients with insomnia and thus indirectly reflects brain function.

Goal(s): This study aimed to explore alterations in cerebral oxygen metabolism in patients with insomnia.

Approach: CS_VO₂ in patients with insomnia and healthy controls was measured by 3D-slicer on quantitative susceptibility mapping (QSM). Statistical analysis was conducted using SPSS.

Results: Cerebral oxygen metabolism was lower in insomnia patients than in healthy controls,  which was associated with sleep efficiency, R-phase share, and total sleep time.

Impact: Our study shows the impact of insomnia on cerebral oxygen metabolism and the ability to assess cerebral function noninvasively by QSM, which is useful in prompting early clinical intervention.

Keywords: Psychiatric Disorders, Treatment, Non-pharmacological therapies; Sleep; Chinese Medicine

Motivation: This study is motivated by the increasing interest in non-pharmacological approaches, like RN12-ARP, to improve sleep quality and address sleep-related problems.

Goal(s): The specific aim is to investigate RN12-ARP's effects on sleepiness, EEG patterns, and brain activity in individuals with insomnia, exploring its potential as a solution for sleep disturbances.

Approach: Seventeen participants undergo RN12-ARP sessions, collecting EEG, sleep diaries, and psychological assessments, analyzed using high-density EEG and MRI.

Results: The study shows that RN12-ARP induces immediate sleepiness, supported by EEG-fMRI. Psychological scales have limited effects, but sleep diaries hint at improved sleep, suggesting potential for insomnia treatment, pending further research.

Impact: The study might pave the way for non-pharmacological interventions like RN12-ARP to address insomnia, improving the well-being of patients with sleep disturbances. Further investigations into the mechanisms behind quick drowsiness are pending, offering hope for alternative approaches to sleep therapy.

Keywords: Peripheral Nerves, Neurography

Motivation: Quantification of myelin in peripheral nerves remains challenging.

Goal(s): To evaluate new imaging techniques that quantify myelin in the peripheral nerve.

Approach:  Myelin-sensitive inversion recovery (MySIR) was compared with inhomogeneous magnetization transfer (ihMT) for its ability to reflect myelin value and spatial resolution in the peripheral nerve.

Results: Myelin values of MySIR and ihMT were strongly correlated. MySIR had a better ability to visualize nerve fascicles than ihMT.

Impact: MySIR could quantify myelin while maintaining high spacial resolution in peripheral nerves.

Keywords: Peripheral Nerves, Nerves, Median, Ulnar

Motivation: Improvements in the medical imaging of nerves have broad medical applications in the diagnosis, tracking, and management of peripheral nerve disease, injury, and treatment. 

Goal(s): We aim to demonstrate the feasibility of quantitative in vivo imaging of median and ulnar nerves using ultrashort echo time (UTE) MRI. 

Approach: UTE magnetization transfer (MT) prepared Cones (UTE MT-Cones), UTE MT Fat-Sat-Cones, and UTE Multi-echo-T₂-FS-Cones sequences were performed in nine healthy adults using a clinical 3T scanner. 

Results: Cross-sectional area (CSA), T₂*, MMF, and all MTR values were lower in the ulnar nerve, but the differences were significant only for CSA, non-fat-sat MTR 800-2k and 500-10k.

Impact: This demonstration of high-contrast, quantitative imaging of the wrist nerve has considerable potential in practical applications for managing and monitoring nerve disease, injury, and treatment.

Keywords: Peripheral Nerves, Nerves

Motivation: The median and ulnar nerves are fine anatomical structures, and these small nerves could not be adequately visualized on conventional MR neurography.

Goal(s): The purpose of this study is to realize high-resolution MR neurography for the diagnosis of peripheral neuropathy of the median and ulnar nerves.

Approach: We performed visualization of the detailed anatomy of the median and ulnar nerves by high-resolution diffusion sensitized-driven equilibrium (DSDE) with deep learning constrained Compressed SENSE (CS-AI) with deep learning constrained Compressed SENSE (CS-AI).

Results: MR neurography with DSDE with CS-AI could clearly visualize the median and ulnar nerves at high resolution within a feasible scan time.

Impact: High-resolution MR neurography with DSDE with CS-AI clearly visualizes the entire median and ulnar nerves, including the small common palmar digital nerves. This may be a useful technique in the diagnosis of peripheral neuropathy of the wrist.

Keywords: Peripheral Nerves, Nerves, denoising, DTI, FA

Motivation: DTI is effective in characterizing nerve pathology but requires a high-resolution scans, resulting in low SNR data.

Goal(s): To analyze the effectiveness of a self-supervised Patch2Self denoising technique on magnitude-averaged and complex-averaged DTI data of human median and ulnar nerve.

Approach: The magnitude-averaged and complex-averaged DTI data was denoised with the Patch2Self algorithm; and DTI fitting performed was performed to obtained estimates of FA, AD, and RD in nerves.

Results: Patch2Self denoising reduced the variability in the data by 20% at the cost of systematic bias, while complex averaging improved the contrast between muscle/nerve and suppressed fat.

Impact: FA estimates obtained from DTI helps monitor nerve regeneration following catastrophic nerve injuries. Improving the quality of the DTI data may improves the reliability of FA estimates so that more subtle treatment effects can be detected.

Keywords: Peripheral Nerves, Diabetes, DTI

Motivation: Electrophysiology is the gold-standard tool to diagnose diabetic peripheral neuropathy (DPN), but it is invasive. We try to find a convenient and reliable technique for diagnosing DPN.

Goal(s): The study aimed to reveal whether DTI of the lumbosacral nerve roots could be used to detect DPN.

Approach: Using a 3T MRI scanner to get the DTI parameters of lumbosacral nerve roots from 2 diabetic patients with and without DPN, respectively, and analyze data using statistical methods.

Results: DTI of lumbosacral nerve roots can detect whether peripheral nerve injury occurs in diabetic patients.

Impact: DTI of lumbosacral nerve roots can not only detect whether peripheral nerve injury occurs in diabetic patients but also quantitatively describe the degree of peripheral nerve injury and has the potential to evaluate the nerve changes after treatment in DPN patients.

Keywords: Head & Neck/ENT, Nerves, multi-shot, reduced-FOV, 3D isotropic DWI, optic nerves

Motivation: Conventional 2D DWI sequences suffer from several disadvantages, therefore hindering the clinical visual assessment of optic nerves. 

Goal(s): This study aims to enable a 3D reduced-FOV multi-shot isotropic DWI sequence for optic nerves DWI and verify its feasibility. 

Approach: The pulse sequence and corresponding reconstruction algorithm of 3D reduced-FOV 2-shot isotropic DWI was developed to achieve effective and accurate reconstruction of optic nerves.

Results: Preliminary results have shown the feasibility of our method in depicting the optic nerves with high resolution and high fidelity, therefore potentially benefiting the clinical applications of optic nerves DWI.

Impact: 3D reduced-FOV multi-shot isotropic optic nerves DWI shows superior advantages of high resolution and high fidelity compared with other conventional DWI sequences, which should be further investigated and applied for clinical applications of optic nerves.

Keywords: Peripheral Nerves, Nerves, Degenerative

Motivation: Multiple studies have shown volumetric changes in the dorsal root ganglia (DRG) in association with various neuropathies, but volumetric changes in patients with low back pain are not much known.

Goal(s): To check a semi-automatic region-growing technique can be used to segment DRG on 3D MR neurography images and to determine if DRG volumes differ in patients.

Approach: 3D MR neurography images were acquired from 10 patients and 4 control subjects at 3T. Segmentation algorithms were applied for DRG volume measurement, and measured volumes were compared between control and patient groups.

Results: Lower DRG volumes were measured with patients.

Impact: Through a semi-automatic 3D region growing technique, dorsal root ganglia volume can be efficiently measured with 3D MR neurography. Morphological assessment of dorsal root ganglia might help to understand overall lumbar spine pathology and low back pain.

Keywords: Peripheral Nerves, Nervous system, Radiomics, trigeminal neuralgia, nomogram, MRI

Motivation: Addressing the diagnostic challenges of Primary trigeminal neuralgia (PTN) and exploring the potential of radiomics combined with clinical features for better accuracy. 

Goal(s): To establish an auxiliary diagnostic model for PTN using radiomic and clinical features. 

Approach: Retrospectively analyzed 116 patients with trigeminal neuralgia, extracting 1316 radiomics features using 3D slicer and studying 13 clinical features. Lasso regression, ICC analysis, univariate and multivariate logistic regression were used for analysis. 

Results: Combining radiomic and clinical characteristics improved the model's AUC values to 0.85. Atrophy of the trigeminal roots might be significant in PTN diagnosis.

Impact: This study enhances PTN diagnosis, guiding clinicians with improved accuracy, potentially benefiting patients. It paves the way for further research on trigeminal root atrophy's role, optimizing treatment strategies and patient care.

Keywords: Structural Connectivity, Neurodegeneration

Motivation: Olfactory bulb and tract imaging with high resolution is required for patient evaluation

Goal(s): Optimized protocol along with super resolution deep learning to improve olfactory bulb and tract imaging 

Approach: Optimized T2 weighted and DTI imaging along with deep learning reconstruction was performed and results were evaluated

Results: Good agreement between existing and proposed methods were observed while the proposed methods improves resolution with better noise performance. 

Impact: This work will allow olfactory system high resolution imaging to serve as a diagnostic tool for patient evaluation.

Keywords: Peripheral Nerves, Diffusion Tensor Imaging, Magnetization Transfer

Motivation: Quantitative and semi-quantitative magnetic resonance imaging investigations of the peripheral nerves in vivo using 7 Tesla are currently limited.

Goal(s): To obtain standard diffusion tensor imaging (DTI) metrics and magnetization transfer ratio (MTR) in the healthy tibial nerve in vivo and to assess the reproducibility of these measures.

Approach: Reproducibility was assessed through repeated measurements (scan-rescan) and calculation of the coefficient of variation between measurements.

Results: The reproducibility assessment results are presented along with normative DTI and MTR measures in the tibial nerve, which can serve as reference in future studies of pathological conditions affecting the lower peripheral nerves.

Impact: This pilot study demonstrates the feasibility of using 7 Tesla magnetic resonance imaging to assess the healthy tibial nerve in vivo using diffusion-weighted and magnetization transfer imaging, opening up the possibilities to investigate lower peripheral neuropathies with higher spatial resolution.

Keywords: Peripheral Nerves, Neurography

Motivation: A more consistent visualization of the thoracic ganglia is needed to aid in identifying abnormal anatomical patterns and disease progression for the formulation of therapeutic strategies.

Goal(s): To prospectively evaluate the clinical feasibility of MR neurography in detecting thoracic dorsal root ganglia and related morphologic information for clinical decisions.

Approach: The T2_FFE, B_FFE, and SHINKEI sequences were applied to identify the best sequence that can precisely provide nerve root visualization and describe the morphological information of thoracic DRG.

Results: T2_FFE offers enhanced nerve visualization and improved image quality, and provides valuable morphological information, with shorter sequence acquisition time.

Impact: This method has a potential role in the diagnosis and treatment of diseases involving unilateral or even bilateral ganglia. By applying morphological MRN, the detailed nerve visualization may help surgeons develop effective DRG-targeted treatment and detect the therapeutic effect.

Keywords: Peripheral Nerves, Neurography, Nervous System, cadaveric MRI, vagus nerve

Motivation: Clinical visualization of the vagus nerve is challenging due to nerve diameter and tortuosity, as well as variation between subjects, making implementation of stimulation therapies difficult.  

Goal(s): Determine feasibility of bilateral vagus visualization in embalmed cadavers using high-resolution imaging.

Approach: Thirteen cadavers were imaged at 0.5-0.6 mm isotropic resolution using 3D constructive interference in steady state (CISS) and volumetric interpolated breath-hold sequence (VIBE). Scanning covered the extent of the vagus from the skull base to the abdomen and imaging was correlated to gross dissection.

Results: The vagus nerve was visualized bilaterally most clearly with CISS and 0.5mm uninterpolated spatial resolution.

Impact: MRI visualization of the vagus, cranial nerve X, could be used to direct future interventions including potential percutaneous MRI-guided procedures. Cadaveric imaging can help optimize acquisitions for future in vivo translation.

Keywords: Head & Neck/ENT, Head & Neck/ENT

Motivation: Identification of the spatial relationship between the parotid tumor and the extracranial segment of the facial nerve can facilitate preoperative planning.

Goal(s): We compared image quality and diagnostic efficacy between double-echo steady-state with water (DESS) and constructive interference in steady-state (CISS) sequences.

Approach: DESS and CISS sequences were used to determine the visibility of the extracranial segment of the facial nerve in healthy volunteers, then locate parotid tumors and facilitate patient diagnosis.

Results: Compared with DESS images, CISS images more reliably showed the location of the facial nerve relative to the lesion in patients with parotid tumors

Impact: CISS demonstrates good visualization of the parotid branches (temporofacial and cervicofacial trunks) compared with DESS. Moreover, CISS is a reliable and direct method for identifying the locations of parotid tumors.

Keywords: Peripheral Nerves, Treatment, trigeminal neuralgia; carbamazepine

Motivation: While MRI have proven valuable in predicting the surgical prognosis of trigeminal neuralgia (TN), studies on the prediction of medical therapy efficacy are still lacking.

Goal(s): Our goal was to identify MRI and clinical characteristics that can predict the efficacy of medical therapy for TN.

Approach: We conducted a blindly evaluation of MRI characteristics of TN. Clinical characteristics was obtained from the medical notes or phone follow-up. The correlation between MRI and clinical characteristics with medical therapy efficacy were subsequently analyzed.

Results: Vertebral artery being culprit vessel and involvement of trigeminal nerve ophthalmic division correlates with drug treatment efficacy.

Impact: The identified MRI and clinical characteristics in patients with TN, which are associated with the efficacy of medical therapy, can assist clinicians in offering informed guidance to patients when deciding between surgical and medical therapy.

Keywords: Head & Neck/ENT, Neurography, CRANI (CRanial Nerve Imaging), Parotid Mass

Motivation: Restricted visualization of the extra foraminal facial nerve inhibits pre-operative decision-making in parotid gland mass regarding nerve preservation.

Goal(s): Using 3D CRANI (CRanial Nerve Imaging) MR sequence, extra foraminal facial nerve was studied, focusing its anatomical relationship to parotid gland mass.

Approach: In 10 patients, post-contrast CRANI sequence was obtained in  3T scanner with 32-ch coil and Compressed SENSE imaging to study its extraforaminal course. Multi-planar and maximum-intensity projections was generated to enhance visibility.

Results: Extraforaminal segments of the facial nerve was well visualized up to its bifurcation. However, the visualization of branches distal to bifurcation in relation to the lesion was poor.

Impact: Extraforaminal facial nerve and its relationship to parotid mass allows surgeons to make better preoperative assessments. CRANI sequence effectively enables proximal nerve tracking while lacks in distal branch visualization in presence of mass; an avenue for future refinements. 

Keywords: Head & Neck/ENT, Brain Connectivity

Motivation: Trigeminal neurogenic tumors involving the peripheral branches are relatively rare, and valueable.Luckly,I collect many kind of neurogenic tumor including rare case.

Goal(s): CT and MR imaging can illustrate related anatomy
and pathway of three peripheral branches of the trigeminal neurogenic tumors.

Approach: We obtained MR and  CT images of all the adult Chinese patients during regular clinical trial with their informed consent. 

Results: Imaging features include irregular thickening and enhancement of the nerve, furthermore to clearly display supra-orbital, infra-orbital, and inferior alveolar nerves respectively.Surprisely,it  also widened the neural foramen those neurogenic nerves pass through. 

Impact: A thorough understanding of its anatomy and pathwayis very important, both in diagnosis and treatment of tumors.It really provided a important clinical guiding for proper practice.

Keywords: Neurotransmission, Neuro, pharmacological MRI, functional MRS

Motivation: An integrated imaging approach using functional magnetic resonance imaging (fMRI) and functional proton magnetic resonance spectroscopy (fMRS) can increase our understanding of the functional response to antidepressant medication like es-ketamine.

Goal(s): We aimed to assess the dose- and time-dependent effects of the antidepressant es-ketamine on the functional brain response. 

Approach: We used an interleaved fMRI and fMRS experiment to assess whole-brain changes in BOLD signal and neurometabolite changes in the anterior cingulate cortex.

Results: Es-ketamine increased glutamate levels and the BOLD signal, and decreased aspartate and glucose levels in the first 10-15 minutes following administration, with specific dose-dependent effects.

Impact: Our results show both dose- and time-dependent neurometabolic and hemodynamic responses to es-ketamine. Understanding the contribution of these two determinants of the functional response might advance our understanding of the effects of antidepressant medication on the human brain.

Keywords: Neurotransmission, Brain

Motivation: The assessment of GABA and Glx levels within the brain with MEscher-Garwood Point RESolved Spectroscopy (MEGA-PRESS) has an important role in the diagnosis and treatment of neuropsychiatric disorders.

Goal(s): We evaluate the daily fluctuations of GABA levels within the parietal lobe (PL) and anterior cingulate gyrus (ACC) regions.

Approach: The GABA+, GABA+/Cr , Glx/Cr ,Glx were measured at six different time points throughout the day using MEGA-PRESS.

Results: Significant variations in GABA+/Cr levels within the PL region, with the lowest point occurring at 9:00 and the highest peak occurring at 21:00 . The melatonin levels were positively correlated with GABA+/Cr within the ACC region.

Impact: GABA changes in localized brain regions are strongly associated with many psychiatric disorders. The outcomes of this study could be used to guide the diagnosis and treatment of neuropsychiatric disorders.

Keywords: Neurotransmission, Brain, 7T, MRS, Laminar fMRI, Brain Function

Motivation: To gain insights into the neurochemical underpinnings of brain function by investigating the association between the cortical depth-dependent BOLD signal and neurometabolite concentrations in the PCC.

Goal(s): Examine the relationship between neurometabolites and laminar-fMRI metrics in the PCC to uncover layer-specific functional relationships

Approach: Laminar fMRI and MRS at 7T and assessment of correlations between cortical depth-dependent fMRI-metrics and neurometabolites

Results: Glutamate positively correlated with the fMRI ECM-metric in the intermediate layers of the PCC, suggesting increased long-range neural excitability. Conversely, lactate concentration negatively correlated with the fMRI ALFF-metric in superficial layers of the PCC, indicating potential layer-specific metabolic and functional differences

Impact: This study exposes the intricate relationship between regional neurometabolite concentrations and laminar fMRI metrics in the posterior cingulate cortex (PCC) that contribute to our understanding of brain activity and functional connectivity at rest

Keywords: Neurotransmission, Spectroscopy

Motivation: Examining the impact of the excitatory-inhibitory balance on cognitive function in healthy individuals holds great significance in research.

Goal(s): Exploring the excitatory-inhibitory balance at the neurotransmitter level and studying the relationship between excitatory-inhibitory balance and cognitive functions.

Approach: The study involved the collection of glutamate and γ-aminobutyric acid using magnetic resonance spectroscopy in 268 healthy participants, alongside the assessment of cognitive function in the subjects.

Results: In the anterior cingulate cortex, we observed a positive correlation between glutamate and γ-aminobutyric acid levels. Additionally, we found that a higher ratio of excitatory balance was associated with improved working memory performance at this specific location.

Impact: This study enhances our understanding of the excitatory-inhibitory balance at the neurotransmitter level and identifies a correlation between the level of excitatory inhibition and cognitive function. These findings provide valuable insights into the impact of excitatory inhibition on cognitive function.

Keywords: Neurotransmission, Metabolism, Spectroscopy, Brain, Animal

Motivation:  Electroconvulsive shock (ECS) therapy is an established treatment for drug-resistant depression. However, the status of neurometabolic activity during ECS-induced seizure is not clear. 

Goal(s): This study was carried out to measure neurometabolic activity during ECS-induced Seizure. 

Approach: ¹H-[¹³C]-NMR spectroscopy was used in conjunction with intravenous [1,6-¹³C₂]glucose or [2-¹³C]acetate infusion to measure neuronal and astroglial metabolic activity, respectively. 

Results: The neurometabolic activity was increased while astroglial activity remained unchanged during ECS-induced seizure. Moreover, the anaerobic glucose consumption was highly increased, suggesting the dominance of glycolysis during the seizure state.

Impact: The assessment of metabolic activity of Glutamatergic, GABA’ergic neurons, and astrocytes during ECS-induced seizures, provides valuable information about glucose consumption during enhanced energy demand, and the interplay of different cell types in the brain.  

Keywords: Neurotransmission, Spectroscopy, Functional MRS

Motivation: Changes in GABA and Glutamate associated with positive/negative BOLD activation in the visual cortex due to central and peripheral stimulation of the visual field are measured with functional MRS.  

Goal(s): How does stimulation of the central visual field affects concentrations of excitatory and inhibitory neurotransmitters and could these changes be consistent with negative and positive BOLD activation? 

Approach: An fMRS paradigm was applied on four volunteers to measure average changes in GABA and Glu due to alternating periods of central and peripheral visual stimulation, using a non-edited semi-LASER sequence.

Results: GABA decreased on average with peripheral stimulation while Glutamate showed an inconsistent trend. 

Impact: Indirect effects of negative and positive BOLD activation can be explored with functional MRS by measuring changes of GABA (inhibitory) and Glutamate (excitatory) neurotransmitters in the visual cortex resulting from central and peripheral stimulation of the visual field.

Keywords: Neurotransmission, Spectroscopy, Hurst Exponent, Excitatory-Inhibitory Balance, Brain Criticality

Motivation: Animal and computational studies have been used as a basis to assume a link between excitatory-inhibitory (E/I) ratio and Hurst exponent (H) in the human brain; however, it has yet to be sufficiently demonstrated in healthy human subjects.

Goal(s): We seek to test the E/I-Hurst link in the visual cortex during rest and movie-watching.

Approach: Multi-echo functional MRI, sLASER, and MEGAPRESS sequences are used in 17 healthy human adults (ages 21-53 years; 13 female, 4 male) with MRS voxel ROI in visual cortex.

Results: E/I and Hurst are not significantly correlated in either the MRS voxel ROI or visual network.

Impact: Hurst exponent (H) is assumed to correlated with excitatory-inhibitory (E/I) ratio without sufficient human evidence. Given the role of E/I imbalance in neuropsychiatric illness and the technical difficulty to measure it, understanding if H acts as its proxy is critical.

Keywords: Neurotransmission, Spectroscopy

Motivation: Many types of visual stimuli were reported effective for visual perception. However, it’s uncertain whether certain types of visual stimuli illicit larger responses.

Goal(s): We aim to measure the metabolic changes in response to different types of visual stimuli to observe which types of visual stimuli can excite larger and more consistent responses.

Approach: We designed three different types of stimuli sessions ( non-sense images, houses, and faces)  for visual stimulation and observed the metabolic changes in the fMRS data at 5T.

Results: Preliminary experiments show that compared to non-sense images and “no interesting” houses, faces stimulate larger responses with dynamic increase.

Impact: An fMRS study is implemented to measure the dynamic changes in response to different types of visual stimuli. Preliminary experiments indicate that faces stimulate larger responses.

Keywords: Neurotransmission, Spectroscopy, BOLD, Brain, Magnetic Resonance, Neural activation, Temperature, Thermometry, Visual cortex, Visual stimulation

Motivation: It is unclear if magnetic resonance spectral response to neural activation offers insight into brain temperature variation. 

Goal(s): To measure visual cortex temperature during visual stimulation.

Approach: During single and continuous stimulation, spectra were collected from the activated visual cortex region (n = 4). Frequency shifts of the N-acetyl aspartate, creatine and choline peaks from the water peak were calibrated to measure temperature using pre-determined regression equations for each peak. Spectral responses to neural activation were estimated as percentage changes in their height, width and area. 

Results: Continuous neural activation was associated with significant decrease in visual cortex temperature.

Impact: Continuous neural activation of the visual cortex increases cerebral blood flow to the activated region, which helps dissipate heat from visual cortex tissues as observed in the consistent temperature reduction. The observed spectral changes indicate clear response to neural activation.

Keywords: Neurotransmission, Deuterium, Neurometabolism, brain, Neuroscience, Spectroscopy

Motivation: Lower sensitivity of ¹³C NMR spectroscopy requires longer acquisition time while quantifying brain metabolites. An alternative technique is essential to aid faster detection.

Goal(s): To evaluate the kinetics of ²H labeling brain metabolites from [6,6’-²H₂]glucose using ²H NMR spectroscopy.

Approach: The cortical extracts of rats infused with [6,6’-²H₂]glucose were analyzed using ²H NMR spectroscopy. 

Results: The signals of deuterated Glc_C6, Glu_C4, Lac_C3, GABA_C2and Gln_C4 are seen in the  ²H NMR spectrum of cortical extract obtained after 90 min of [6,6’-²H₂]glucose infusion. The resonances of Asp_C2, Glu_C2, and Glu_C3 are absent suggesting complete loss/dilution of ²H from the TCA cycle intermediates beyond α-ketoglutarate.

Impact: Judicious use of ²H NMR together with suitable deuterated substrates may an alternative for neurometabolic analysis in neurological disorders.

Keywords: Neurotransmission, Metabolism, Spectroscopy, Brain, Animal

Motivation: Recently FDA has approved S-ketamine for the treatment of drug-resistant depression. However, the impact of long-term use of ketamine on mood, cognition, and neurotransmitter pathways is not clear.

Goal(s): To assess the impacts of chronic ketamine administration on mood, cognition, and neurometabolism in the mice model. 

Approach: ¹H-[¹³C]-NMR spectroscopy in conjunction with an intravenous [1,6-¹³C₂]glucose infusion was used for neurometabolic measurements.

Results: Ketamine administered mice showed hyperactivity, reduced cognition, and depression-like phenotypes. Moreover, chronic ketamine exposure increased the metabolic activity of glutamatergic and GABAergic neurons in the cerebral cortex.

Impact: Ketamine, a rapid-acting antidepressant, has been abused as a party drug historically. This study was performed to uncover the adverse effects of chronic ketamine administration and will be useful in designing better treatment approaches for depression.

Keywords: Neurotransmission, Metabolism, Glutamate, GABA, Isoflurane, Urethane

Motivation: Anesthetics are routinely used in surgery, and neurometabolic analysis in different neurological conditions but their impact on brain energy metabolism is not well understood.

Goal(s): To evaluate the impact of anesthetics on excitatory and inhibitory neurotransmission in the brain.

Approach: Infuse [1,6-¹³C₂]glucose in mice maintained under isoflurane (1.5%) or urethane (1.5 g/kg), and monitor ¹³C labeling of brain metabolites by ¹H-[¹³C]-NMR spectroscopy.

Results: The glutamatergic and GABAergic neurometabolic activity was suppressed in isoflurane as well as in urethane anesthetized mice. The inhibitory and excitatory neurotransmission increase or decrease together with the brain activity.

Impact: These findings will have implications for the interpretation of function signals in the brain.

Keywords: Neurotransmission, Neuroscience

Motivation: The functional role of Inhibitory tone in the motor cortex is not completely understood. Previous work has been limited by the coarse spatial resolution in single-voxel spectroscopy.

Goal(s): We applied a novel high spatial resolution MR spectroscopic imaging technique to test the relationship between inhibitory tone and motor network (MN) connectivity.

Approach: We performed voxel-wise analysis of neurochemical data to correlate measures of inhibitory and excitatory tone with age as a confounder, MN and default mode network (DMN).

Results: In the motor hand areas, we demonstrated a reciprocal correlation of inhibitory tone with MN and DMN connectivity. Inhibitory tone could “switch” node connectivity.

Impact: The connectivity of key motor network nodes could be influenced by their inhibitory tone and the excitation–inhibition difference. This finding advances the understanding of motor network function and could be a target for modulation in clinical settings.

Keywords: Neurotransmission, Brain, Migraine,GABA

Motivation: To investigate the variation of GABA concentrations in the anterior cingulate cortex and posterior cingulate cortex of migraine patients without aura during a migraine attack and the interictal stage.

Goal(s): To elucidate the role of GABA in the migraine pathophysiology.

Approach: We prospectively enrolled 12 migraineurs and 16 healthy controls and acquired MEGA-PRESS on a 3T MR from voxels located in the ACC and the PCC.

Results: Among migraineurs,  a significant increase in GABA+ in the PCC during  a migraine attack versus the interictal stage(P=0.0023).  Measurements in ACC and PCC showed a statistically significant elevation of GABA+ in migraineurs than healthy controls(P=0.0017, P=0.0031).

Impact: We speculate that increased GABA levels may reflect a compensating mechanism to reduce a hyperexcitatory state and a protective role for GABA in suppressing headaches. We will probe into the mechanism of GABAergic Drugs for the treatment of migraine.

Keywords: Head & Neck/ENT, Metabolism, coffee, MEGA-PRESS, GABA, MRS, sleepiness

Motivation: The effects of acute caffeine intake on brain metabolite levels remain largely unknown.

Goal(s): Illustrate the sensitivity of MRS to fluctuations in brain metabolites, investigate the difference among different caffeine consumption habit groups and to explore the association between metabolite changes and sleepiness.

Approach: MRS was performed at three time point after the participants consumed coffee.

Results: GABA+, GPC/GPC + PCH, Ins, Glu, and Glx levels were significantly altered after caffeine consumption. The levels of Glu, GPC, Cr + PCr, Glx, and Ins were significantly influenced by caffeine consumption habits. GABA+ levels in TH voxels significantly correlate with subjective sleepiness.

Impact: This study should prove valuable in the study of the sensitivity of MRS to fluctuations in brain metabolites, the brain metabolites alteration differences among different coffee consumption habits, and MRS studies of GABA.

Keywords: Neurotransmission, Spectroscopy, GABA, Glx

Motivation: Reproducibility is critical in longitudinal studies to monitor subtle alterations of GABA and Glx concentration in neurodegenerative disorders.

Goal(s): To evaluate the reproducibility of GABA and Glx measurements of the midbrain and basal ganglia regions in healthy subjects.

Approach: The MEGA-PRESS sequence was scanned twice with a two-week gap for each subject to obtain the GABA and Glx level in the left basal ganglia and bilateral midbrain. The reproducibility was evaluated.

Results: We observed good agreement between two scans for the GABA and Glx quantification based on the Bland-Altman analysis.

Impact: The reproducibility analysis of GABA and Glx measurements in the basal ganglia and midbrain regions are needed for the follow-up studies. The preliminary results informed that applying ¹H-MRS to investigate the progression of GABA and Glx levels is applicable.

Keywords: Head & Neck/ENT, Cancer, Head and Neck Cancer, T1rho mapping, T2 mapping, Radiotherapy, Treatment responses

Motivation: Early assessment of response to radiotherapy may be useful to crucial for effectively managing head and neck cancer (HNC).

Goal(s): To evaluate the response to radiotherapy in HNC using quantitative 3D T1rho and T2 mapping. 

Approach: T1rho and T2 mapping was performed on a healthy volunteer and three HNC patients, one of whom was scanned before, during, and after radiotherapy.

Results: Significant decrease in T1rho and T2 values of the tumor were observed two weeks after starting and completing radiotherapy. However, the values in other tissues, such as muscles, remained relatively stable across the three scans.  

Impact: This study evaluates the feasibility of using quantitative T1rho and T2 mapping to assess the treatment response to radiotherapy for head and neck cancer. This information could be valuable in tailoring individualized treatments for patients with head and neck cancer. 

Keywords: Head & Neck/ENT, Fat, Pulsatile tinnitus. Sigmoid sinus dehiscence. Intracranial hypertension. Cerebrospinal fluid dynamics. Cerebrospinal fluid volume.

Motivation: The mechanism of sigmoid sinus dehiscence (SSWD) in pulsatile tinnitus (PT) patients remains unclear.

Goal(s): To assess the cerebrospinal fluid (CSF) dynamics and volume of SSWD-PT with intracranial hypertension by phase-contrast magnetic resonance imaging (PC-MRI).

Approach: Thirty-five PT patients with SSWD and intracranial hypertension identified on dual-phase contrast-enhanced CT (DP-CECT) and brain magnetic resonance venogram (MRV), respectively. And 35 age-, gender-, and handiness-matched healthy volunteers. All participants underwent T1-weighted volumetric and PC-MRI.

Results: The body mass index, regurgitant fraction and CSF volume were significantly higher and the mean velocity, peak velocity and mean flux were significantly slower in SSWD-PT.

Impact: We found the CSF dynamics and volume changes in SSWD-PT with intracranial hypertension, which may be related to blood flow dynamics changes in sigmoid sinus and presence of PT. These results suggest treatment for SSWD-PT should be more comprehensive.

Keywords: Head & Neck/ENT, Multimodal, Multiparameter Quantitative MRI

Motivation: Dysthyroid optic neuropathy (DON) is a rare yet highly significant complication of thyroid associated orbitopathy (TAO), which requires urgent treatment. However, diagnosing this condition is a formidable challenge due to the absence of well-defined criteria for its identification.

Goal(s): The aim of this study was to use multiparameter MRI for diagnosing DON.

Approach: Fifty-five patients were enrolled, who underwent MRI, including conventional imaging, T1 mapping, T2 mapping, and mDIXON Quant sequences for providing quantitative parameters.

Results: The quantitative parameters could offer reliable evidence for the differentiation of DON from TAO, especially T1 values of extraocular muscles and water fraction of orbital fat.

Impact: The native T1 values of extraocular muscles combined with water fraction of orbital fat provided more accurate diagnostic ability of DON in TAO patients. Moreover, the pathological presentation of fibrosis of extraocular muscles associated with DON may occur.

Keywords: Head & Neck/ENT, Nerves

Motivation: Trigeminal neuralgia is characterized by vascular compression of the trigeminal nerve, while neurogenic hypertension results from vascular compression in the medulla oblongata.

Goal(s): To investigate the pathogenesis of TN in conjunction with hypertension and identify the vessels responsible,

Approach: we conducted a retrospective population-based study including 457 TN patients,

Results: and found a significant link between neurovascular conflict and hypertension. Specifically, arteries near the root entry zone, such as the anterior inferior cerebellar artery, vertebrobasilar artery, and superior cerebellar artery, were more associated with hypertension, especially when pain localized in the V2,3 area. Conversely, the posterior inferior cerebellar artery displayed an opposing trend.

Impact: Patients with TN combined with neurogenic hypertension are recommended to take microvascular decompression (MVD) operation, who have these conditions in our study, will show potential improvements in their hypertension.

Keywords: Head & Neck/ENT, Head & Neck/ENT, Cochlear Implant Artifacts

Motivation: A cochlear implant (CI) contains an implanted magnet placed under the scalp. Newer rotating magnet designs facilitate safe and comfortable scanning up to and including 3 T. However, MRI of the head is still confounded by image distortion.

Goal(s): To characterise CI artefacts at 3 T.

Approach: T2DRIVE and T1-weighted mDIXON images were acquired in CI users, normally-hearing participants, and a phantom.

Results: Visibility of bilateral internal auditory canals and cochleae varied across three CI users. Pre-surgical assessment will be beneficial on an individual basis to maximise the chances of successful post-operative MR acquisition.

Impact: Bilateral internal auditory canals can be visualised despite the presence of a cochlear implant (CI): an assessment of the effect of a CI on the usability of clinical MR images in CI users, normally-hearing individuals, and a phantom.

Keywords: Head & Neck/ENT, Head & Neck/ENT

Motivation: HYDROS is useful method for detection of endolymphatic hydrops in patients with Meniere’s disease, but it has a potential risk for motion of patients during the acquisition because of its long scan time, resulting in misalignments of subtraction images.

Goal(s): To develop a new sequence, called interleaved HYDROPS, which acquires PPI and PEI images with an interleaved manner in one single scan.

Approach: We developed the interleaved 3D IR-prepared TSE with variable inversion delays. Interleaved HYDROPS were compared with conventional HYDROPS for image quality, particularly in the motion simulated situation.

Results: Initial findings indicated good feasibility of interleaved HYDROPS, encouraging further clinical evaluation.

Impact: Interleaved HYDROPS could provide PPI and PEI images with minimized motion effects during scan, compared with conventional separately acquired sequence. It holds promise for increasing robustness for motion-induced subtraction errors, but further studies are warranted to confirm its full potential.

Keywords: Head & Neck/ENT, Cancer, Nasopharyngeal Carcinoma

Motivation: Complications from radiotherapy in nasopharyngeal carcinoma impact patient quality of life, necessitating methods to determine the optimal radiation dose for patients. 

Goal(s): To evaluate Synthetic MRI's ability to monitor clival invasion and its changes during treatment in nasopharyngeal carcinoma patients. 

Approach: T1, T2 and PD values of clivus were acquired before treatment, at radiation doses of 6420cGy and 7062cGy, and were compared with each other.

Results: Prior to treatment, the clival T1 values in clival invasion patients were higher than those without clival invasion. No difference was found in Quantitative values between the radiation dose reached 6420cGy and 7062cGy. 

Impact: Synthetic MRI can assess clival invasion in nasopharyngeal carcinoma and its changes during radiation treatment, potentially enabling the evaluation of the optimal radiation dose for patient.

Keywords: Head & Neck/ENT, Quantitative Imaging

Motivation: The objective of this study was to examine the potential impact of chemotherapy on the brain in patients with nasopharyngeal carcinoma (NPC) using Multiplex (MTP) MR imaging sequence, which generate multiple contrasts with one-time scan.

Goal(s): We aimed to investigate the altered MTP parameters and their correlation with clinical cognitive scores before and after chemotherapy.

Approach: All patients underwent MTP imaging, and the data were analyzed using BrainTool software.

Results: The findings revealed that patients who underwent chemotherapy exhibited reduced brain volume and elongated T2Star in some brain regions, although no significant correlation was observed with clinical cognitive scores.

Impact: The newly MTP MR sequence can evaluate brain alterations in NPC patients following chemotherapy. The observed decrease in volume values and increase in T2Star properties within brain regions may suggest neuron and myelin sheath damages in NPC patients after chemotherapy.

Keywords: Head & Neck/ENT, Tumor

Motivation: Malignancies originating from the mucosa of the oral cavity and oropharynx are considered as one of the most prevalent types of malignancies.

Goal(s): We intended to evaluate the diagnostic performance of MAGIC in distinguishing between benign and malignant pathologies in the oral cavity and oropharynx regions.

Approach: This study enrolled 45 patients with malignancies and 19 patients with benign pathologies. The quantitative values were measured and histogram features were extracted from lesion regions. ROC curves were constructed to evaluate the diagnostic efficiency.

Results: The quantitative mappings showed similar diagnostic performance as morphological images. The diagnostic efficacy was further improved with all images combined.     

Impact: Considering the routine diagnosis of malignancies mainly based on morphologic and contrast-enhanced images, the present study validated the clinical value of MAGIC to acquire both of the morphological and quantitative images during a single scan without contast.

Keywords: Head & Neck/ENT, Neuro, facial morphology, craniofacial atlas

Motivation: Current research lacks an understanding of the relationship between the craniofacial structure and the brain, and this connection is of significant importance for pre-diagnosis and neuroscience research.

Goal(s): Develop a MRI-based craniofacial atlas to support clinical-neuroscience research, particularly in understanding the relationship between the brain and craniofacial structure.

Approach: Gathered and processed MRI scans from 148 subjects, employing specialized algorithms for detailed craniofacial and skull mapping, aiding neuroscience research.

Results: The study revealed variations in skull thickness, particularly in the occipital bones, and a significant negative correlation between cortical and skull thickness in specific regions. A comprehensive facial atlas was also successfully developed.

Impact: Our research provides a clear research framework and atlas that can be used to explore the relationship between neurological disorders and craniofacial morphological changes in future studies. Additionally, it offers a potential approach for non-invasive and rapid preclinical diagnosis.

Keywords: Head & Neck/ENT, Head & Neck/ENT, Normative Modeling; Meige syndrome; Facial Paralysis; Machine Learning

Motivation: This study delves into the variations in gray matter volume among patients with Meige Syndrome (MS), facial paralysis (FP), and healthy controls. 

Goal(s): It aims to unveil the neurological mechanisms underlying these conditions. With a sample of 53 FP patients, 31 MS patients, and 102 healthy controls, the research assesses disease severity and conducts high-resolution MRI imaging. 

Approach: Normative modeling and machine learning algorithms are employed to identify differences in specific brain regions. 

Results: Results reveal significant variations in gray matter volume, particularly in the anterior cingulate region, shedding light on the importance of this area in understanding these conditions.

Impact: This study's outcomes could transform clinical practice and research in Ménière's Syndrome and facial paralysis. Enhanced diagnostic and treatment methods may significantly improve patients' quality of life, fostering exploration of innovative therapies and a deeper understanding of these conditions.

Keywords: Head & Neck/ENT, Spectroscopy, Precision and accuracy, brain, tinnitus

Motivation: The measurement of GABA+ using in vivo proton magnetic resonance spectroscopy requires adequate reproducibility and reliability for its use in clinical research and as a potential biomarker. 

Goal(s): We aimed to determine the within-session test-retest reproducibility and reliability of GABA+ in the auditory cortex of individuals with tinnitus. 

Approach: A MEGA-sLASER sequence for GABA+ measurement using two consecutive within-session blocks was performed on 38 participants over 2 scanning days.

Results: GABA+ quantification in the auditory cortex demonstrated similar reproducibility and reliability when using either a total creatine (tCr) or water reference (GABA+/tCr: CV=5.6%, ICC=0.69, 95% CI [0.52-0.80]; GABA+/water: CV=5.6%; ICC=0.73, 95% CI [0.58-0.83]). 

Impact: Auditory cortex GABA+ quantification with MEGA-sLASER in a clinical population with GABA+ abnormalities in the region of interest can be achieved with reproducibility and reliability that is comparable to what has been reported in other brain regions of healthy controls. 

Keywords: Head & Neck/ENT, Head & Neck/ENT, Graves’ ophthalmopathy; T2 mapping

Motivation: T2 relaxation time (T2RT) of extraocular muscle (EOM) derived from T2 mapping has been reported to be useful for staging patients with Graves’ ophthalmopathy (GO). However, due to the particularity of orbital anatomy, various region of interest (ROI) selection methods have been used in the process of T2RT measurements in GO.

Goal(s): This study aimed to evaluate the performance of T2 mapping based on different ROIs for staging GO.

Approach: T2RT-mean and T2RT-max values of EOM on coronal T2 mapping  were measured and analyzed.

Results: Taking reproducibility and diagnostic performance into consideration, T2RT-mean was found to be an ideal biomarker for staging GO.

Impact: Taking reproducibility and diagnostic performance into consideration, T2RT-mean of EOM derived from T2 mapping was found to be an ideal biomarker for staging GO compared to T2RT-max.

Keywords: Head & Neck/ENT, Head & Neck/ENT, Nasopharyngeal carcinoma; Depth of Invasion; Synthetic MRI

Motivation: Deeply infiltrating tumors have a poor prognosis and need close follow-up. Whether the depth of invasion could serve as a quantitative prognostic indicator in NPC. The prognostic assessment value of synthetic MRI (SyMRI) needs further analysis.

Goal(s): To explore the value of two quantitative methods in prognostic assessment in NPC, including depth of invasion and SyMRI.

Approach: This study prospectively included NPC patients, and utilized multiple statistical methods to construct and validate two methods.

Results: Depth of invasion and SyMRI are important quantitative methods.

Impact: Tumor invasion depth is an unignorable metric, and combining it with SyMRI may provide a quantitative and objective approach for clinical treatment.

Keywords: Head & Neck/ENT, CEST & MT, Synthetic imaging, Sinonasal Lesions, APT

Motivation: Distinguishing between benign and malignant sinonasal lesions is crucial for determining the appropriate treatment regimen and predicting patient outcomes. 

Goal(s): To evaluate the performance of synthetic MRI (SyMRI), combined with amide proton transfer (APT)-weighted MRI (APTw) in differentiating between malignant and benign sinonasal lesions. 

Approach: Eighty patients with sinonasal lesions were underwent the SyMRI and ATPw scan and the quantitative parameters were analyzed.

Results: T1, T2, PD and APT values were significant between the benign and malignant groups. Combined SyMRI and APTw had the best diagnostic efficiency.

Impact: Combined the SyMRI with APTw would function as a quantitative and contrast-free approach, significantly enhancing the differentiation of benign and malignant sinonasal lesions. This method also helps overcome the limitations associated with the superficial nature of nasal endoscopic sampling.

Keywords: Head & Neck/ENT, Image Reconstruction, deep learning, reconstruction, magnetic resonance imaging, eye, image quality

Motivation: Extraocular rectus muscles (ERMs) are essential for precise eye movement control, and their assessment is vital for diagnosing eye conditions. Magnetic Resonance Imaging (MRI) is preferred due to its superior soft-tissue resolution, but it has limitations.

Goal(s): To determine whether Deep Learning Reconstruction (DLR) can enhance eye image quality and diagnosis.

Approach: A study with 28 patients used DLR on ocular MRI. Two readers evaluated the images independently, and statistical analyses were conducted.

Results: DLR significantly improved ERM depiction and overall image quality compared to conventional MRI. Interobserver agreement was good, especially for structural depiction. DLR produced clear, detailed images, enhancing diagnostic potential.

Impact:  This study demonstrates that DLR improves MRI image quality for assessing eye conditions, potentially leading to more accurate diagnoses, reduced repeat examinations, and enhanced patient care.

Keywords: White Matter, CEST & MT

Motivation: Standard structural MR imaging techniques are not able to provide information on the metabolic state of white matter lesion. Specialized imaging techniques such as NOE and GluCEST can complement these conventional images by leveraging larger chemical shifts at 7T. 

Goal(s): To observe potential NOE and GluCEST contrast differences in a leukoencephalopathy patient at 7T.

Approach: GluCEST and NOE images were acquired at 7T. NOE experimental z-spectral data was fit with multi-pool Lorentzian fitting to produce five individual pool fits.

Results: DS, MT, and rNOE differentiated white matter changes as well as GluCEST changes in the gray matter in a leukoencephalopathy patient. 

Impact: This method of ultra-high field MR imaging for patients with demyelinating conditions can provide complementary metabolic information to standard structural imaging that, when tracked longitudinally, can yield improved diagnostic outcomes and understanding of disease mechanism for this patient population.

Keywords: White Matter, Magnetization transfer, NOE

Motivation: Nuclear Overhauser Effect (NOE) is based on dipolar cross relaxation mechanism that enables the indirect detection of aliphatic protons via the water proton signal. This work focuses on determining the reproducibility of the transient-Nuclear-Overhauser-Effect (tNOE) of the healthy human brain at 3 Tesla.    
 

Goal(s): To establish reproducibility of tNOE in the brain regions of healthy subjects at 3T.

Approach: We scanned three healthy subjects multiple times to determine inter-day reproducibility of tNOE on 3T.

Results: The inter-subject coefficient of variations (CoV) of tNOE from GM and WM were 5.12% and 3.97%, respectively. The intra-subject tNOE CoV range for GM and WM was 0.24%-4.0%.  

Impact: This work will facilitate the use of tNOE at 3T to investigate macromolecular (lipid and proteins) derangements in different diseases with significantly reduced scan time and improved specificity compared to steady state NOE.    

Keywords: White Matter, Brain, Whole brain spectroscopic imaging, neurite orientation distribution and density imaging, Superior longitudinal fasciculus

Motivation: Superior longitudinal fasciculus (SLF) is critical in multiple normal functions. It is imperative to co-localize white-matter tract of SLF with metabolite maps to facilitate simultaneous analysis of microstructural integrity and metabolite alterations.

Goal(s): To evaluate relationships among metabolite ratios and diffusion MRI derived parameters along the path of SLF in normal healthy adults.

Approach: The associations between whole brain spectroscopy derived Cho/Cr, Cho/NAA ratios and diffusion MRI derived FA, MD, fICVF, fIso and ODI parameters were assessed along the length of SLF segments II-III.

Results: Strong significant correlations between Cho/Cr and Cho/NAA ratios and FA, MD, f_icvf were observed.

Impact: Diffusion MRI and whole brain spectroscopy could be used to study the covariation of white matter microstructure and metabolism. Multiparametric normative tract profiles established over larger cohorts could serve as the basis for early detection of white matter anomalies.

Keywords: White Matter, White Matter, Gamma-aminobutyric acid

Motivation: The alteration of cortical GABA levels in WMH patients and whether it mediates the association of WMH volume with executive function remain unclear

Goal(s): We investigated the cortical GABA levels, and whether cortical GABA mediates the association between WMH and executive function in the WMH people.

Approach: We used the independent samples test,general linear model,partial correlation analyses and mediation analysis.

Results: Patients with moderate to severe WMH showed lower GABA+/Cr in the anterior cingulate cortex (ACC) and worse executive function than mild WMH patients. And  the GABA level in ACC mediates the association between white matter hyperintensities and executive function in WMH patients.

Impact: The GABA+/Cr level in the the anterior cingulate cortex had a critical role. And it mediates the association between white matter hyperintensities and executive function in the WMH patients.

Keywords: White Matter, White Matter, Aging, Alzheimer's Disease, Spectroscopy

Motivation: APOE4 has been linked to increased amyloid and tau deposition and microstructural WM changes in Alzheimer’s, but despite the major role of APOE in myelination, whether WM metabolism is altered in individuals at risk for Alzheimer’s remains unknown.

Goal(s): To examine if choline, a constituent of myelin and a marker of membrane turnover, is associated with APOE4, CSF p-tau181 (a marker of tau burden), and WM volume (a marker of neurodegeneration).

Approach: Cognitively unimpaired elderly with and without APOE4 underwent ¹H-MRSI. Relationships between WM choline, APOE4, tau, and WM volume were assessed.

Results: No associations were found between WM choline and any marker.

Impact: WM metabolism is not associated with genotype, tau, or neurodegeneration in healthy elderly, but given that amyloid deposition is the earliest Alzheimer’s pathological hallmark, additional investigations with amyloid biomarkers are needed to better characterize WM metabolism in the preclinical stage.

Keywords: White Matter, Diffusion/other diffusion imaging techniques, myelin, brain, myelin water imaging, diffusion

Motivation: Literature suggests that white matter (WM) may be specifically affected in polyG diseases, a novel class of genetic neurodegenerative diseases including fragile X-associated tremor/ataxia syndrome (FXTAS) and neuronal intranuclear inclusion disease (NIID).

Goal(s): To use advanced MRI to characterize WM in polyG disease.

Approach: 3T myelin water imaging and diffusion tensor imaging in participants with FXTAS and NIID.

Results: FXTAS and NIID demonstrated diffuse cerebral WM damage and myelin loss. Middle cerebellar peduncle (MCP) changes were seen in FXTAS, but not in NIID. Diffusion hyperintense foci in the MCP (FXTAS) and frontal WM (FXTAS and NIID) matched foci of highest dysmyelination.

Impact: Fragile X-associated tremor/ataxia syndrome and neuronal intranuclear inclusion disease show diffuse cerebral white matter abnormalities and myelin damage, and spatially differential changes in the frontal white matter and middle cerebellar peduncle.

Keywords: White Matter, White Matter, UTE imaging, Myelin

Motivation: Many neurological disorders are characterized by myelin damage and loss. Robust long T2 suppression is of critical importance for accurate myelin quantification due to myelin's low proton densities.  

Goal(s): To develop a new UTE imaging approach that enables sufficient long T2 suppression for selective myelin imaging.

Approach: A 3D DIR-UTE sequence was developed for selective myelin imaging on a 3T clinical scanner. The technical feasibility was tested by phantom and in vivo studies.

Results: The long T2 signals were sufficiently suppressed with the DIR scheme. The myelin proton fraction in white matter regions quantified by the DIR-UTE was 5.42±0.35%.

Impact: The long T2 signals were sufficiently suppressed with the DIR scheme. The myelin proton fraction in white matter regions quantified by the DIR-UTE was 5.42±0.35%.

Keywords: White Matter, White Matter

Motivation: There is a need for selective myelin imaging with minimal contamination from long-T2 water components.

Goal(s): To develop a new contrast mechanism for direct visualization of myelin using a three-dimensional adiabatic inversion recovery prepared ultrashort echo time (3D IR-UTE) sequence.

Approach: We employed the long-T2 signal phase transition in 3D dual-echo IR-UTE imaging to find the optimal inversion time (TI) necessary to null water signals for selective myelin imaging in a clinical 3T scanner. 

Results: Myelin signal could be selectively detected by 3D IR-UTE sequence based on long-T2 phase transition and optimal TI  for both ex vivo and in vivo brains.

Impact: The 3D IR-UTE sequence allows direct imaging of myelin, which is important for accurate diagnosis and assessment of multiple sclerosis (MS), Alzheimer’s disease (AD), and other neurological diseases.

Keywords: White Matter, White Matter

Motivation: Studying ex vivo tissue requires preservation by formalin-fixation or freezing.  Effects of these methods on tissue parameters compared to fresh tissue is unknown.

Goal(s): We investigated how freezing/thawing and fixation affect T1, T2, and MT properties in brain tissue. We created a protocol to apply MR methods (T2-MESE, biexponential T1, qMT, ihMT, NODDI) to pathology specimens in the Michigan Alzheimer’s Disease Research Center (MADRC) repository. 

Approach: We scanned the same ex vivo sheep brain samples fresh, frozen/thawed, and fixed, and compared their relaxation and MT properties.

Results: Effects of fixation are most prominent in white matter and especially influence T1 and T2 relaxation.

Impact: Thawed tissue exhibits more similar relaxation and MT properties to fresh tissue than fixed tissue does. In MR studies that use ex vivo tissue samples, such as those correlating MR to histology, thawed tissue may be preferable to formalin-fixed.

Keywords: White Matter, Quantitative Imaging, myelin water imaging, multicomponent analysis, multiple sclerosis, quantitative MRI, qMRI, white matter

Motivation: Multicomponent T₂ (mcT₂) analysis is the go-to tool for mapping myelin in vivo. Resolving T₂ spectra, however, is highly challenging due to substantial ambiguity in the multidimensional space of microstructural configurations.

Goal(s): Accurate and reproducible myelin water imaging.

Approach: A spatially-global data-driven mcT₂ analysis was employed, relying on the identification of tissue-specific mcT₂ configurations prior to performing voxel-wise analysis. A new scheme was developed for correcting transmit field (B₁⁺) inhomogeneities.

Results: Successful application of the data-driven technique is demonstrated on numerical phantom, healthy volunteers, and for identifying pathology in normal-appearing tissue of subjects with multiple sclerosis.

Impact: The data-driven approach constitutes a new paradigm for multi-component T₂ fitting, yielding unprecedented accuracy and high robustness. Application on MS patients’ data highlights the potential of data-driven MWF values as a biomarker for pathology in normal appearing tissue.

Keywords: White Matter, Simulations

Motivation: To improve the accuracy of myelin water fraction (MWF) calculations.

Goal(s): To develop multi-component phantom for MRI simulators and to validate the accuracy depending on pulse sequences and imaging parameter settings.

Approach: First, five different electron micrographs of the normal central nervous system (CNS) were divided into two regions (my and ax/ie), and the percentage of each component was calculated. Second, each proton density (PD) was set as a percentage of the divided area. 

Results: We developed multi-component water phantom and could demonstrate the SPGR signal variations to B₀ inhomogeneity on an MRI simulator using our multi-component water fraction phantom.

Impact: Our multi-component phantom derived from electron microscopic analysis may be useful to evaluate the differences in MWF values between each signal model, e.g., qMT and mcDESPOT.

Keywords: White Matter, Microstructure

Motivation: Axon diameter and myelination are essential for conduction of action potentials and therefore related to brain function. However, the relationships between them in white matter (WM) across different species are not well understood.

Goal(s): To investigate the relationship between axon diameter and myelination in human and macaque brain WM.

Approach: We estimate axon diameter and myelin water fraction (MWF), and derive fiber g-ratio, using macaque and human brain data acquired on a preclinical scanner.

Results: Microstructure parameters exhibit consistent patterns across WM tracts and species. Regions with smaller axons tend to have higher packing density and MWF; fiber g-ratio is relatively stable.

Impact: The weak correlations between dMRI measures and MWF suggest they can provide complementary information about fiber morphology. The regional variations of these microstructure measures will be baseline for investigating changes in abnormal tissue conditions such as demyelination and axonal loss.

Keywords: White Matter, Diffusion/other diffusion imaging techniques, Myelin, Neurodegeneration

Motivation: Myelin degeneration is implicated in many neurological diseases. Diffusion and susceptibility MRI provide metrics to assess myelin degeneration. 

Goal(s): Treatment can affect myelination in neurodegeneration and diffusion metrics can be used to follow these changes. 

Approach: After detailed registration to the Allen Atlas, we examined key white matter areas (corpus callosum, fornix). 

Results: We observed diffusivity increases and kurtosis/axonal water fraction decreases in AD mice. We also saw an inverse trend in HD mice. Interestingly, this was reversed by treatment and confirmed histologically. 

Impact: We find diffusion changes suggesting myelin loss in Alzheimer’s mice, and inverse changes in Huntington’s mice that are reversed by disease-modifying treatment and confirmed histologically. Advanced diffusion metrics can be useful biomarkers to monitor myelin changes and treatment in neurodegeneration.

Keywords: White Matter, Relaxometry, Myelin

Motivation: While higher cardiorespiratory fitness (CRF) is recognized as vital for brain health, its specific connection with white matter integrity, especially cerebral myelination, remains unclear.

Goal(s): This study aims to investigate the association between CRF and myelin in cognitively unimpaired adults spanning a wide age range.

Approach: We employed our advanced multicomponent MR relaxometry method to measure myelin water fraction, a direct proxy of myelin content, while CRF was assessed using the maximum rate of oxygen consumption, peak VO₂.

Results: Our results indicate that higher peak VO₂ is associated with greater myelin content across several white matter structures, particularly among older adults. 

Impact: This work lays the foundation for future investigations to further elucidate the mechanisms underlying the relationship between cardiorespiratory fitness and cerebral myelination, as well as its potential as an interventional target in addressing age-related neurodegeneration, including in Alzheimer’s disease.

Keywords: White Matter, White Matter, MMF, MWF, MPF, Myelin

Motivation: Myelin imaging metrics have varying degrees of association with histology but have not yet been correlated with each other. 

Goal(s): To explore correlations between macromolecular protein, myelin water, and non-aqueous myelin content on a 3T clinical scanner.

Approach: Seven healthy volunteers were scanned using an MT-Cones sequence to provide for two-pool MT modeling of macromolecular proton fraction (MMF), a STAIR-STE-Cones sequence to quantify myelin water fraction (MWF), and a STAIR-UTE-Cone to estimate non-aqueous myelin proton fraction (MPF).

Results: Strong, significant correlations were found between these three myelin imaging biomarkers with R values of 0.856, 0.876, and 0.775, respectively

Impact: Strong positive correlations were found between the three imaging biomarkers of macromolecular, myelin water, and non-aqueous myelin components. This may help in understanding the value of these myelin imaging biomarkers in the assessment of neuroinflammatory and neurodegenerative diseases.

Keywords: Structural Connectivity, High-Field MRI, sleep

Motivation: The habenula is evolutionarily conserved brain region which play a crucial role in sleep regulation

Goal(s): To analysis the structural and functional relationship between habenula and individual sleep by 5T ultrahigh-resolution MRI

Approach: Using ultrahigh-resolution structural and functional MRI, we parcellated lateral and medial portions of the habenula and calculated structural and functional connectivity on the basis of these parcellations

Results: We parcellated lateral and medial portions of the habenula and identified connectivity with salience, limbic and part of somatomotor networks, which led to the loss in average sleep and cognitive processes

Impact: For the first time we identified the correlation between habenula and individual sleep using 5T ultrahigh-resolution MRI. By analyzing 300 samples high -resolution data, we revealed the neurological basis of individual sleep regulation, and provided new opinions for the mechanism of sleep diseases.

Keywords: Structural Connectivity, Brain Connectivity, Migraine

Motivation: While the pathophysiology of migraine remains incompletely understood, several studies reported connectivity disruptions across large-scale brain networks. 

Goal(s): To study changes in the structural connectome of migraine patients including cortical and subcortical regions as well as the cerebellum, often disregarded.

Approach: We performed tractography on diffusion MRI data and applied graph theory metrics to study connectome changes in episodic migraine patients and their healthy controls, using two different whole-brain parcellations.

Results: Patients show increased global efficiency and decreased characteristic path length, as well as increased connectivity of cerebellar regions with a greater node degree in the posterior lobe of the cerebellum.

Impact: This study sheds light on the importance of including regions other than the cortex in the structural connectome studies of migraine. Indeed, the cerebellum seems to play an important role in migraine, presenting increased connectivity with other regions.

Keywords: Structural Connectivity, Brain Connectivity

Motivation: Neuronal axons (nerve fibers) facilitate complex connectivity patterns, but retrieving fiber architecture with micrometer resolution remains elusive. Meanwhile, thousands of brain histology sections are produced and archived daily.

Goal(s): Here, we show that fiber architecture can be derived with micrometer resolution from new and archived histology sections.

Approach: Using Computational Scattered Light Imaging (ComSLI), we generate detailed microscopic maps of nerve fiber orientations in healthy and diseased, animal and human brain sections prepared with various protocols and stains.

Results: We compare whole-brain results to diffusion MRI. This opens new avenues to studying microscopic brain fiber architecture in a time- and cost-effective manner.

Impact: Using scattered light, we generate micrometer maps of nerve fiber orientations in new and archived histology sections of healthy and diseased, animal and human brains prepared with various protocols and stains. We compare whole-brain fiber orientations to diffusion MRI.

Keywords: Structural Connectivity, Brain Connectivity, Functional connectivity

Motivation: EEG measured directional information flow, cerebral metabolism and structural connectivity are altered in temporal lobe epilepsy, although their interplay have not been elucidated.

Goal(s): To investigate whether and how structural and metabolic connectivity may separately or jointly affect the directional information flow.

Approach: This study proposed a step-wise analysis to study the correlation between directional information flow measured by SEEG and glucose metabolism measured by FDG PET, and to explore their associations with different structural connectivity.

Results: The inward information flow was negatively correlated with FDG uptake. White matter structural connectivity modulated the relationship between SEEG information flow and metabolism.

Impact: Unraveling the underlying association of white matter connectivity and FDG metabolism with directional information flow strength could offer a comprehensive view of neuronal signal propagation and potentially improve seizure onset localization of focal epilepsy.

Keywords: Structural Connectivity, Diffusion Tensor Imaging, Major depressive disorder; Structural connectome; Graph theory

Motivation: Previous studies have demonstrated brain abnormalities in adolescents with major depressive disorder (MDD); however, how the topological organization of brain networks is affected is still unclear.
 

Goal(s): This study aimed to investigate the white matter (WM) structural topology in adolescent MDD.
 

Approach: The topological metrics of WM structural brain networks were analyzed using graph theory method.
 

Results: Adolescent MDD patients showed disrupted topological organization at the global, rich-club and modular levels, exhibited abnormal nodal centralities in multiple regions, and had a decrease in the coupling between structural and functional connectivity.
 

Impact: Our findings suggest widespread disruption of structural brain networks and structural-functional decoupling in adolescent MDD, which may provide new insights into the neurobiology of adolescent MDD.

Keywords: Structural Connectivity, Diffusion/other diffusion imaging techniques

Motivation: To the best of our knowledge, no study in neuroscience has been conducted based on high intelligence (HI) and low intelligence (LI) groups young healthy adults.

Goal(s): This study aims to explore the effect of brain network structures on the intelligence quotient and brain efficiency of healthy adults.

Approach: We focused on the white matter’s topological traits, which demonstrate network performance and structural connectivity differences between the HI and LI groups.

Results: We found structural differences in connections between specific nodes in the HI and LI groups. Intelligence correlated positively with network efficiency and negatively with path length.

Impact: This study innovatively explores the relationship between brain network structures and intelligence in healthy young adults. This study revealed that higher intelligence is associated with efficient brain networks and greater resilience in targeted network disturbances.

Keywords: White Matter, Diffusion Tensor Imaging, exercise

Motivation: The impact of longer exercise durations and its correlation with comprehensive behavioral changes, such as improvements in strength and working memory, remains relatively underexplored.

Goal(s): In this study, we explore the impact of an 8-week strength training program on brain function and structure through multimodal MRI.

Approach: We recruited 21 participants, who had been leading a sedentary lifestyle before enrolling. Utilizing a Siemens Prisma scanner and Human Connectome Project protocols, we obtained multimodal MRI data, covering anatomical scans, diffusion imaging, resting state fMRI, and ASL scans. 

Results: Preliminary findings highlight the importance of microstructural measurements in detecting exercise-induced brain changes.

Impact: This research highlights the potential for using multimodal MRI to characterize exercise-induced white matter plasticity in the brain, particularly in motor-related areas.

Keywords: Structural Connectivity, White Matter

Motivation: Comparative studies on brain structure between humans and macaques across entire brain have not been thoroughly conducted.

Goal(s): The goal of this study is to show the similarities and differences of structural connectivity (SC) in humans and macaques.

Approach: SC was calculated from diffusion-weighted imaging. Based on the SC, the similarity and Least Absolute Shrinkage and Selection Operator (LASSO) were used.

Results: High similarity of SC between and within species was observed. LASSO yielded feature extraction of 12 connections.

Impact: This study clearly showed the similarity of white matter structure between and within species in humans and macaques. The method of this study is quantitative and provides valuable insights in translational research.

Keywords: White Matter, Relaxometry, transverse relaxation orientation dependence

Motivation: The orientation dependence of transverse relaxation R₂ in the human brain white matter could be exploited as a potential myelin specific biomarker for assessing demyelinating pathologies.

Goal(s): To investigate the feasibility of characterizing fiber tract specific anisotropic R₂ solely based on DTI.

Approach: A high-resolution public domain Connectome DTI dataset was used for the demonstration. Two major fiber tracts, corpus callosum and corticospinal tract, were segmented, and corresponding orientation dependent R₂ profiles were quantified based on a recently developed model.

Results: Results suggested that anisotropic R₂ could be extracted effectively from DTI, facilitating easy access to a potential myelin specific biomarker.

Impact: In this work, we demonstrated that a single T₂-weighted image (i.e., b=0)  effectively separates anisotropic R₂ from its isotropic counterpart offering an efficient alternative to conventional lengthy R₂ mapping method of incorporating in-vivo axon fiber orientation information from DTI.

Keywords: White Matter, Brain Connectivity, White matter; Diffusion MRI; Functional MRI; Multi-modal

Motivation: The axonal connections in white matter(WM) are vital for brain function, but there is a knowledge gap of the functional role of WM tracks.

Goal(s): To address this, we proposed a method to combine diffusion MRI (dMRI) and functional MRI (fMRI) to map the functional role of WM tracks during tasks.

Approach: To each WM track generated with dMRI, we define the dynamic functional connectivity (DFC) that reflects the functional interaction of the GM it connects. General linear model(GLM) is then employed to measure the activation level during task. 

Results: Meaningful tracks that are associated with various tasks, implicating the activated networks. 

Impact: Our method paves the road to generate a functional atlas of white matter. It is important for understanding the functional architecture of the brain, the mechanism of brain disorders, such as, Schizophrenia, Epilepsy and Traumatic Brain Injury.

Keywords: Head & Neck/ENT, Head & Neck/ENT

Motivation: The underlying structural pathophysiology of visual white matter degeneration in primary open-angle glaucoma (POAG) remains incompletely understood.

Goal(s): To characterize macro- and micro-structural abnormalities in the optic tract and optic radiation of POAG by multiple morphology and diffusion metrics derived from diffusion spectrum imaging(DSI)

Approach: DSI was performed on 34 bilateral POAG patients and 25 healthy controls (HCs), and multiple morphology and diffusion metrics were calculated and compared.

Results: Significant differences emerged in morphology and diffusion metrics between POAG patients and HCs.

Impact: Our demonstration of multiple morphology and diffusion changes in POAG utilizing DS suggests the macro- and micro-structural white matter abnormalities, which could be used for assessing POAG degenetation

Keywords: White Matter, Multimodal

Motivation: Substantial effort has been invested into understanding how brain structure constrains function. However, research has primarily focused on understanding structure, rather than linking brain dynamics to it.

Goal(s): Compare oscillation propagation delays estimated using neuronal avalanches from MEG resting-state data with the underlying white matter structure estimated through tractography.

Approach: We characterised the relationship between pathways length and the related propagation delays, using deterministic and probabilistic approaches, and looking at different frequency bands.

Results: While higher frequency bands scale proportionally with propagation delays and length, lower frequency bands show constant delays, regardless of tract length, for both deterministic and probabilistic tractography.

Impact: This multi-modal approach has the potential to improve understanding of how underlying white matter structure constrains brain [oscillatory] activity. Future research will focus on integrating additional structural and microstructural measurements to inform biophysical models of brain structural and functional connectivity.

Keywords: White Matter, Neuro, 7T MRI; Papez circuit; segmentation; deep learning

Motivation: The core components mediating the Papez circuit are important targets or localization indicators for the clinical development of deep brain stimulation (DBS) in treating Alzheimer's disease (AD), refractory epilepsy, and other diseases.

Goal(s): Exploring deep learning model for segmentation of the core components mediating the Papez circuit in brain 7T-MRI

Approach: Fifty-five healthy volunteers were enrolled, and SegResVAE Net was used to segment core components.

Results: The SegResVAE Net exhibited the best Dice scores for the mammillary body, mammillothalamic tract, and the average of all components.

Impact: Segmentation of the core components mediating the Papez circuit would be beneficial for treating Alzheimer's disease (AD), refractory epilepsy, and other diseases.

Keywords: White Matter, White Matter

Motivation: T₂ (or R₂=1/T₂) contrast is widely used for the study of neurological disease. Understanding how the relaxation relates to tissue microstructure may improve its clinical utility.

Goal(s): To explore white matter microstructural correlates to R₂.

Approach: R₂ mapping in healthy volunteers using Gradient Echo Sampling of Spin Echo at 7T. Atlas based analysis of fiber tracts, and analysis of corpus callosum subsections.

Results: R₂ variation was about 25% across the white matter and correlated inversely with the diffusion MRI metric of axonal diameter.

Impact: T2 contrast is complex and influenced by factors including tissue iron and lipid content. Tissue microstructure, in particular white matter fiber thickness, may also play a role. Studying their relative contribution will help understand the nature of pathological tissue changes.

Keywords: White Matter, Tractography & Fibre Modelling, Spaceflight

Motivation: The effects of spaceflight on the central nervous system, and in particular the brain’s white matter (WM), are poorly understood.

Goal(s): To gain knowledge about the effect of long-duration spaceflight on the brain's WM.

Approach: We performed the first fixel-based analysis of diffusion MRI scans of 18 cosmonauts before and after long-duration spaceflight.

Results: We show widespread changes in the WM after spaceflight, which are predominantly macroscopic rather than microscopic. Moreover, we detect a net increase in the amount of WM fibers in the left superior and left middle cerebellar peduncles, providing evidence for neuroplasticity in the brain induced by long-duration spaceflight.

Impact: Better understanding and monitoring of the effect of space flight on the brain is crucial to ensure the health of space crews and their performance during long-duration space missions.

Keywords: Multiple Sclerosis, Multiple Sclerosis, Network analysis, Structural disconnection, Morphometric similarity

Motivation: Multiple sclerosis can be modelled as a network disorder. Progressive demyelination and neurodegeneration lead to structural disconnection and disruption of the morphometric similarity between gray matter regions.

Goal(s): To obtain measures of structural disconnection and morphometric similarity networks from conventional MRI sequences and test whether they are sensitive to disease status and clinical disability.

Approach: 461 patients were imaged. Using publicly available software, we computed structural disconnection using white matter lesions masks and normative tractography atlases. Likewise, morphometric similarity was computed from standard FreeSurfer outputs.

Results: Structural disconnection and morphometric similarity networks are sensitive to disease status and explain clinical disability.

Impact: Measures of structural disconnection and morphometric similarity networks obtained from conventional MRI sequences are sensitive to multiple sclerosis and its related physical and cognitive disability. Our approach could represent a way to overcome the limitations of the standard network analyses.

Keywords: Radiomics, Modelling, Mixture-Modeling, White Matter Lesions

Motivation: Analyzing multiple sclerosis (MS) lesions longitudinally is challenging, and requires consistent and robust imaging, processing, and statistical methods. Conventional binary lesion segmentations might overlook significant pathology changes as degeneration is continuous. 

Goal(s): To track subtle changes in MS lesions using statistically derived metrics. 

Approach: We introduced a two-component Mixture Model (MM) to track longitudinal changes qT1 with regions of interest (ROIs) and compared it with conventional image metrics.

Results: In our longitudinal analysis, the MM approach uncovered changes missed by traditional methods suggesting MM may help capture and understand longitudinal evolution of MS lesions.

Impact: Our novel mixture modeling analysis approach may untangle unique aspects of biological processes in MS lesion evolution, offering a valuable alternative to conventional image analysis methods.

Keywords: Functional/Dynamic, Spectroscopy

Motivation: Bridge the knowledge gap in understanding the central mechanisms of chronic low back pain (CLBP) and the effects of spinal manipulation (SM).

Goal(s): To use 1H-MRS to investigate metabolic differences in the posterior cingulate cortex (PCC) during spinal manipulation for chronic low back pain (CLBP).

Approach: The approach involved recruiting CLBP patients and healthy controls, performing 1H-MRS in the posterior cingulate cortex (PCC) before and after spinal manipulation (SM), and correlating metabolite changes with clinical outcomes.

Results: CLBP patients exhibited altered brain metabolism in the posterior cingulate cortex (PCC), with changes in specific metabolites, and these abnormalities improved after spinal manipulation (SM).

Impact: The research provides insights into the central mechanisms of chronic low back pain (CLBP) and the potential therapeutic benefits of spinal manipulation, which could inform better pain management strategies.

Keywords: White Matter, Brain, Autism Spectrum Disorder, Precision Medicine, Replicability

Motivation: Heterogeneity of neuroimaging findings remains a challenge to identify specific brain-related phenotypes in ASD. Quantitative metrics of individual deviation across brain measurements are needed for parsing variation and identifying individuals who may or may not have abnormal brain structure.

Goal(s): This study aims to quantify individual brain differences in individuals with and without ASD.

Approach: We investigated the Mahalanobis distance to characterize multidimensional brain measures of microstructure in individuals with and without ASD in a set of white matter regions.

Results: We found multivariate Mahalanobis distance is superior to univariate comparisons at distinguishing between individuals with and without ASD.

Impact: Normative modeling and multivariate approaches may provide informative metrics for parsing heterogeneity in the multivariate patterns of brain development in autistic individuals.

Keywords: White Matter, Brain

Motivation: Chronic hypoperfusion is a central mechanism of cerebral small vessel disease (CSVD), but studies using different methods have shown different results.

Goal(s): To compare the associations between CSVD and CBF measured by phase-contrast MRI and ASL in the same cohort.

Approach: 69 subjects were totally recruited in the study. WMH, FW, and tFA were used to reflect the disease severity. The associations between CSVD and CBF measured by two methods were investigated.

Results: Compared to CBF_PC, CBF_ASL showed a negative association with FW and a positive association with tFA. The ratio of CBF_ASL to CBF_PC was also correlated with FW and tFA.

Impact: Future studies need to consider the differences between CBF measured by ASL and phase-contrast MRI and choose a more appropriate method according to the research purpose.

Keywords: White Matter, Kidney, hemodialysis

Motivation: The relationship between white matter hyperintensity (WMH) and altered cerebral blood flow (CBF) in maintenance hemodialysis patients remains unclear.

Goal(s): The study aims to explore the regulation of changes for CBF and its relationship with WMH burden in hemodialysis patients.

Approach: Hemodialysis patients were divided into two groups based on whether their CBF decreased after 3-year therapy. The severity of white matter hyperintensity was compared between the two groups.

Results: Compared with the increased CBF group, higher burden of deep WMH was found in the decreased CBF group.

Impact:  This association between WMH and decrased CBF in maintenance hemodialysis be beneficial to the exploration of the complex mechanisms underlying the development of cerebral abnormalities during hemodialysis.

Keywords: White Matter, Neurodegeneration

Motivation: The factors that influence iron deposition in the normal-appearing white matter (NAWM) of the brain have yet to be thoroughly examined.

Goal(s): This study aimed to measure brain iron levels in a community population and identify factors affecting NAWM iron levels.

Approach: Brain iron load was assessed using quantitative susceptibility mapping.

Results: Age, hypertension, T2DM, smoking, BMI, and APOE4 affect iron metabolism in certain NAWM brain regions. Moreover, the mean susceptibility values of the corpus callosum are significantly related to some cognitive tests.

Impact: We could identify the potential factors that could affect iron levels in the white matter and accurately map iron in this part of the brain. This information could help us better control confounding variables in future research.

Keywords: White Matter, White Matter, Aging, Small Vessel Disease, Neurodegeneration

Motivation: Dirty-appearing white matter (DAWM) might be an early marker of cerebral small vessel disease (SVD) progression.

Goal(s): To investigate whether dirty-appearing white matter (DAWM) on brain MRI is related to long-term progression of SVD markers in a cohort of community-dwelling older adults.

Approach: We visually rated DAWM volume fraction on baseline FLAIR images (n=2506) and related this to progression of multiple SVD MRI markers at the 5.2-year follow-up.

Results: Global and occipital DAWM is associated with an increase in global white matter hyperintensity (WMH) volume at follow-up. This suggests that DAWM is an early marker of SVD, preceding WMH.

Impact: The presence of DAWM on MRI might help in early risk stratification of older adults at risk for cognitive decline due to SVD, and in that way allow for selection of individuals for preventive lifestyle interventions and treatment trials.

Keywords: White Matter, White Matter, obsessive-compulsive disorder

Motivation: Diffusion tensor imaging (DTI) is a useful imaging technique to investigate white matter (WM) integrity and previous studies had revealed the disruption of WM related to neuropathology in obsessive-compulsive disorder (OCD). However, few study had reliably located the defect at track level.

Goal(s): To investigate the WM integrity in OCD on a whole brain level using newly developed tractography method.

Approach: We used Tracts Constrained by Underlying Anatomy (TRACULA) software to investigate the WM integrity in OCD.

Results: We found widespread disruption of WM integrity in OCD, and for the first time, we observed abnormality in bilateral acoustic radiation in OCD.

Impact: Using the innovated fiber tractography methodology, we were able to detect abnormality in bilateral acoustic radiation in OCD, which had been suggested by previous study using resting state fMRI.

Keywords: White Matter, Fetus

Motivation: There is a controversial argue about the prognosis of fetuses with isolated ventriculomegaly in clinical practice.

Goal(s): Application of diffusion Magnetic Resonance Imaging (dMRI) in fetuses with isolated ventriculomegaly to explore structure changes of white matter fibers.

Approach: Collecting brain dMRI data in isolated ventriculomegaly and healthy fetuses, analyzing differences in white matter structure between the two groups using diffusion tensor imaging (DTI) and fixel based analysis (FBA) methods.

Results: Significant differences were found in DTI or FBA parameters of white matter fibers including the inferior longitudinal fasciculus, corpus callosum, fornix, sagittal stratum and corticospinal tract between the two groups.

Impact: There are changes in the brain white matter structure in intrauterine fetuses with isolated ventriculomegaly, which provides a certain objective basis for potential risks of neurodevelopmental disorders and prenatal counseling.

Keywords: Neurotransmission, Quantitative Imaging, systemic lupus erythematosus; quantitative MRI; white matter microstructure

Motivation: Neuropsychiatric disorders are common symptoms in systemic lupus erythematosus (SLE) patients. However, investigations into altered white matter (WM) microstructure caused by SLE were insufficient.

Goal(s): Investigate WM microstructure alterations and their association with anxiety and depression in SLE patients using synthetic MRI (SyMRI) technique.

Approach: T1, T2 and myelin content, acquired by SyMRI, were compared between 52 SLE patients and 24 health controls.

Results: Longer T1 relaxation time and lower myelin content were found in several WM regions, and anxiety in SLE patients was found to be correlated with a decrease in myelin content in the fornix.

Impact: The demyelination of the fornix may be a significant factor leading to anxiety in patients with systemic lupus erythematosus.

Keywords: White Matter, Neonatal

Motivation: To investigation of cerebral asymmetry in full-term newborns and alterations in the lateralization of the infant brain with white matter injury

Goal(s): To explore brain volume laterality in normal full-term newborns and the effect of infant with WMI on laterality.

Approach: Calculated asymmetry index, used non-parametrically to test the significant, compared the difference of AI with the WMI group.

Results: The distribution of lateralized significance in brain regions between groups was near the same. Significant differences were found between the groups in the hippocampus, amygdala, superior temporal gyrus middle part GM, occipital lobe GM, superior temporal gyrus middle part WM, and caudate nucleus.

Impact: WMI can cause localized lateralized changes in brain regions, which may be associated with future adverse developmental outcomes and might be a biomarker for predicting prospective developmental outcomes of WMI.

Keywords: White Matter, White Matter

Motivation: White matter lesion (WML) is a neuroimaging signature of cerebral small vessel disease (CSVD), commonly comprising both vascular and nonvascular components for which assessment methods remain to be developed.

Goal(s): To investigate the feasibility of using multimodal MR imaging to separate vascular and nonvascular components in WML.

Approach: Twelve patients with CSVD were prospectively included and underwent 3T MR imaging. Magnetization transfer ratio (MTR) was derived from magnetization transfer imaging. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were derived from diffusion tensor imaging.

Results: MTR was found to correlate with ADC and FA differently in WML as compared to normal-appearing white matter.

Impact: Appropriate separation of vascular/nonvascular components in WML can help differential diagnosis and treatment formation of CSVD. The sensitivity of combined MTR/FA/ADC can be further verified by comparing CSVD with other neurological diseases that present WML but have nonvascular pathogenesis.

Keywords: White Matter, White Matter, CADASIL, WMH, longitudinal studies

Motivation: In CADASIL, the relationship between white matter hyperintensities (WMH) changes and disease progression remains unknown. 

Goal(s): To estimate WMH changes, accurate segmentations are mandatory but remain challenging to obtain automatically because of patients MRI variability and heterogeneous contrast between WMH and normal appearing white matter. We aim to decrease correction time required to reach accurate results.

Approach: We used an incremental learning approach with a supervised algorithm from baseline segmentation data up to the final follow-up data to improve results and reduce manual correction time.

Results: A significant improvement of segmentation sensitivity and a reduction of manual correction time were obtained.

Impact: To accurately investigate the WMH progression in CADASIL, we propose an individual-based incremental training approach, with repeated learning of the segmentation algorithm from subsequent corrected data obtained along follow-up, to reduce the final manual correction time as much as possible.

Keywords: White Matter, Aging, cognitive impairment

Motivation: It is still unclear what the mechanism of the effect of white matter hyperintensities (WMHs) and cognitive impairment is.

Goal(s): To use intravoxel incoherent motion (IVIM) to evaluate the microvascular and parenchymal microstructural changes of WMHs and to investigate their association with cognitive impairment.

Approach: The IVIM parameters were compared between patients and controls, different ROIs, and different WMH severity. Additionally, a multivariate linear regression analysis was conducted to explore the factors influencing cognitive scores.

Results: WMH patients had higher parenchymal diffusivity than the control group. Furthermore, increased parenchymal diffusivity was associated with an increased risk of cognitive decline.

Impact: The IVIM technique has the potential to provide a quantitative marker of parenchymal diffusivity for assessing the severity of WMH and may be useful in quantifying cognitive dysfunction in patients with WMH.

Keywords: Infectious Disease, Spectroscopy, HIV, metabolites

Motivation: Chronic HIV infection is associated with widespread brain metabolite imbalance. However, few studies attempted to quantitate changes in brain metabolites in people with HIV (PWH) before and after initiating antiretroviral therapy (ART) treatment.

Goal(s): the aim of this study is to evaluate changes in brain metabolites in PWH, before and after initiating ART, at the whole-brain level using MRSI spectroscopic imaging (MRSI).

Approach: In this longitudinal study, changes in MRSI derived metabolite are evaluated before and after ART treatment using an atlas-based approach.

Results: Our results showed persistent neuro-inflammation in HIV subjects post-ART despite maintaining viral suppression.

Impact: This study advocates the need for continued monitoring of their brain health of PWH even after starting ART.

Keywords: Infectious Disease, Metabolism

Motivation: Many long-COVID patients experience fatigue and post exertional malaise which are primary symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Understanding the similarities and differences between long-COVID and classic ME/CFS could provide insights into the disease mechanisms.

Goal(s): To measure brain anatomy and oxygen metabolism between the two groups.

Approach: Clinical standard and advanced MRI techniques measuring the venous oxygenation were applied. The fatigue level was assessed by questionnaires.

Results: No differences in brain anatomy were observed between the groups, but the long-COVID group had significant lower venous oxygenation than the healthy control group and the classic CFS group.

Impact: Many long-COVID patients fulfill diagnostic criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Compared to structural changes, metabolism-related parameters, such as venous oxygenation of the brain, may be more sensitive to changes related to long-COVID and CFS disease mechanisms.

Keywords: Neuroinflammation, COVID-19

Motivation: The symptoms of brain fog include problems with concentration, memory, attention, which result in difficulties with communication. This can make it extremely difficult for an individual to carry out daily tasks and responsibilities as well as maintain relationships deteriorating their quality of life.

Goal(s): To investigate white matter alteration in Long-COVID.

Approach: Voxel-wise analysis of core white matter voxels using advanced MRI metrics and neuropsychological scores. 

Results: Results highlight promising perspective for further investigations and potential clinical interpretation of Long-COVID syndromes

Impact: The addition of MRI enables a more thorough exploration of the diverse cognitive dimensions affected in individuals experiencing brain fog and perhaps the possibility to understanding the involvement of WM alterations as either a risk factor or consequence of Long-COVID. 

Keywords: Infectious Disease, COVID-19, Glymphatic system;DTI-ALPS

Motivation: Central nervous related sequelae are often reported in recovered COVID-19 patients. It’s unclear whether recovered patients have glymphatic impairment and clinical correlation.

Goal(s): Assessing glymphatic function in recovered patients and the clinical correlation.

Approach: 61 recovered patients and 38 healthy controls were enrolled. Glymphatic function was assessed using DTI-ALPS and compared between recovered and HC subjects.

Results: The impairment of glymphatic function was observed in recovered patients and was more obvious in older patients. It was correlated with sleep quality and anxiety status in a subgroup of recovered patients. 

Impact: Our study firstly provided evidence of glymphatic function impairment in recovered COVID-19 patients. 

Keywords: Infectious Disease, COVID-19, Magnetic Resonance Spectroscopy, Anosmia, Orbitofrontal Cortex

Motivation: Olfactory impairments caused by COVID-19 have been addressed in neuroimaging findings over the past years. However, long-term complications on brain orbitofrontal cortex (OFC) needs to be further investigated.

Goal(s): Our goal was to assess metabolites level change in the brain OFC region in COVID-induced anosmia subjects in comparison to healthy population.

Approach: 54 subjects categorized into control, short- and long-term anosmia groups were studied using single voxel MRS. Metabolite level alterations of their brain OFC region were investigated. 

Results: We found that NAA, Cho, and Cr levels in brain OFC region decreased as COVID-induced anosmia duration and severity increased.

Impact: The demonstrated results of alteration in brain metabolites level influenced by the severity of COVID-induced anosmia highlights MRS as a robust assessment tool for physicians to better investigate olfactory function impairment in the brain orbitofrontal cortex.

Keywords: Infectious Disease, COVID-19

Motivation: COVID-19's neurological effects remain ambiguous, with limited exploration of neuroimaging changes versus clinical symptoms, especially through pre-SARS-CoV-2 exposure longitudinal imaging, remains less explored.

Goal(s): Understand brain change patterns and identify therapeutic targets for post-COVID-19 brain injury and neuropsychiatric effects.

Approach: Utilized consistent neuroimaging on patients in acute recovery across two centers. Employed multiple clinical tools to gauge neuropsychiatric manifestations. Blood samples analyzed for protein profiles indicative of inflammation and neural damage.

Results: Found significant vulnerability in the limbic lobe, observed contrasting pathological changes in symmetrical brain regions, and highlighted potential genetic and neurotrophic factors influencing neuropsychiatric symptoms post-COVID-19.

Impact: This study offers clinicians a clearer path to target COVID-19-related neuropsychiatric symptoms. It prompts further inquiry into genetic influences on brain alterations, enabling tailored therapeutic strategies for affected patients.

Keywords: Infectious Disease, COVID-19

Motivation: Post-Acute Sequelae of COVID-19 of neurological origin (neuroPASC), such as brain fog and anxiety, are not well understood.

Goal(s): To study volumetric changes in the brain’s limbic structures in COVID-19 patients with neuroPASC such as brain fog.

Approach: 29 COVID-19 patients with neuroPASC and 29 matched controls underwent ultrahigh field brain MRI at 7T. Hippocampal subfields and amygdala subnuclei were segmented with FreeSurfer and studied across neuroPASC subgroups.

Results: Several subunit volumes were significantly decreased in COVID patients compared to controls across neuroPASC subgroups. Sex-based differences were also present.

Impact: There may be subtle changes in the volumes of the brain’s limbic structures in COVID patients with neuroPASC compared to controls. These changes may be related to neuroPASC symptoms and may depend on sex differences.

Keywords: Infectious Disease, COVID-19, brain changes, Omicron, young adults, mild symptom, SARS-CoV-2

Motivation: The existence of brain structural abnormalities in young adults with mild Omicron infections remains unclear.

Goal(s): This study aimed to investigate short-term brain structure changes in this specific patient group.

Approach: Young adult patients and age- and sex-matched controls were enrolled, and brain structures were assessed on T1-MPRAGE images. One-way ANOVA, Kruskal-Wallis tests, and logistic regression were employed to determine differences among groups.

Results: While whole brain volume didn't significantly differ among groups, subtle alterations in various regions within cerebral cortex, white matter, and cerebrospinal fluid were observed during the acute phase, with a tendency of recovery over time.

Impact: Short-term structural changes in brain were observed in this study. The findings suggest cerebral impairments at the early stage of infection with SARS-CoV-2 Omicron even in individuals with mild symptoms.

Keywords: Infectious Disease, COVID-19, Independent Component Analysis

Motivation: To understand the cognitive deficits of Long Covid (LCov).
 

Goal(s): What are the brain locations with different BOLD activity in LCov?

Approach: Two consecutive fMRI were acquired in 19 LCov and 16 healthy controls (HC) with a 7 Tesla scanner during the cognitive color-word Stroop task.  Run2 was affected by fatigue induced by Run1. BOLD time series were processed with the CONN toolbox and submitted to independent component analysis (group ICA).

Results: ICA detected widespread deficits in LCov activity and sensorimotor excesses. The extent of LCov activity differences supports the hypothesis that global Covid19 infection affects brain-wide BOLD activity and regulatory function.

Impact: Our discovery of brain-wide changes in Long Covid BOLD activity supports the mechanism of brain-wide Covid-19 infection inducing cognitive deficits. Research should be directed to therapies that eliminate cerebral infection and facilitate and monitor recovery from virus inflicted damage.

Keywords: Infectious Disease, Brain, COVID-19, Biomarkers, Fatigue, Spectroscopy

Motivation: Persistent fatigue after recovery from SARS-CoV-2 shows pathologies comparable to chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME). It is unknown if disruptions in mitochondrial functions caused by SARS-CoV-2 persists in post COVID fatigue as dysregulated mitochondrial homeostasis.

Goal(s): We aim to investigate if post-COVID fatigue relates to perturbations of mitochondrial function in the brain representing signs of neuroinflammation, redox imbalance, and neuronal dysfunctions.

Approach: Proton MR spectroscopy was performed on post-COVID fatigue patients targeting at posterior cingulate gyrus (PCG), one of the most metabolically active regions.

Results: We found reduced level of antioxidants and neuronal activity in post-COVID fatigue patients.

Impact: Proton MR spectroscopy in PCG of post-COVID fatigue patients shows signs of redox imbalance and reduced neuronal activity, suggesting of long-term dysregulations in mitochondrial homeostasis persisting after SARS-CoV-2 infection. SARS-CoV-2 infection may lead to further neurodegenerations post-recovery.

Keywords: Infectious Disease, COVID-19

Motivation: Brain network alterations in acute phase of coronavirus disease 2019 patients (acute-COVID) with fatigue has not yet been elucidated.

Goal(s): Our goal was to determine the characteristics of alterations in brain network and the neurobiological mechanisms in acute-COVID patients with fatigue.

Approach: We utilized graph theory analysis to assess brain network alterations in COVID-19 patients.

Results: Results demonstrated the abnormalities in brain network in acute-COVID patients with fatigue, involing left insular gyrus and right inferior frontal gyrus. Morever, the normalized characteristic path length of global brain in acute phase of COVID-19 could predict the development of chronic symptoms.

Impact:  Our functional MRI findings highlight abnormal brain network metrics in acute phase COVID-19 patients with fatigue, offering valuable neuroimaging marker for early clinical intervention in long-COVID patients.

Keywords: Infectious Disease, COVID-19, Arterial Spin labelling, Brain, Brain Connectivity, Diffusion Tensor Imaging, Microstructure, Multimodal, Spectroscopy, Perfusion

Motivation: There is an urgent need to understand the biological basis of long-COVID.

Goal(s): To elucidate long-term consequences of SARS-CoV-2 infection in the brain using advanced MRI.

Approach: In a multisite study, we collected single-voxel MRS, diffusion MRI, pCASL and T2 FLAIR MRI, to investigate the neurochemistry, microstructure, perfusion, and white matter hyperintensities (WMH) in participants suffering from long-COVID.

Results: Participants with long-COVID have long-lasting effects (that persist years after acute infection) in the neurochemistry, microstructure, and perfusion, primarily in the brainstem, midbrain and diencephalon, and their connecting tracts, without the presence of overt white matter pathology.

Impact: Multi-modal advanced MRI demonstrates long-lasting effects of COVID-19 in the brain, including neurochemical and microstructural abnormalities and perfusion deficits. These insights may facilitate the treatment and care of people suffering from long-COVID.

Keywords: Infectious Disease, Quantitative Susceptibility mapping, PASC, COVID-19

Motivation: The etiology of persistent and enigmatic neurological symptoms in post-acute sequelae of COVID-19 (PASC) remains unclear.

Goal(s): To utilize quantitative susceptibility mapping (QSM) to compare iron levels in the basal ganglia of individuals with neurological symptoms of PASC, recovered COVID-19 patients, and uninfected controls, thereby identifying potential biomarkers for the condition.

Approach: QSM imaging was performed on three distinct cohorts: PASC, post-COVID non-PASC, and uninfected subjects

Results: Elevated QSM values, indicative of iron accumulation, in the putamen and caudate nucleus were observed in PASC patients.

Impact: The study aims to offer a novel imaging perspective on PASC, potentially leading to a better understanding of its neurological aspects and aiding in the development of targeted therapies for affected patients.

Keywords: Infectious Disease, COVID-19

Motivation: It was unclear that if the brain function would be changed after multiple COVID-19 infections when the psychological burden incremented.

Goal(s): To evaluate the long-term brain brain change of the patients who transformed from mildly emotional problem after the first COVID-19 infection into severely one after multiple infections. 

Approach: The patients with mildly emotional abnormality after once infection (control group) and others  transformed from mild into severe abnormality after multiple COVID infections (patients group) were included. The parameters derived from BOLD and DTI were compared after 3-6 months.

Results: The patients group had a decreased FA and increased ALFF in some brain areas. 

Impact: The abnormalities in these brain areas could help clinicians to understand the potential machine of the transformation of mild emotion problem into severe emotion problem after another COVID infection.

Keywords: Infectious Disease, Diffusion/other diffusion imaging techniques

Motivation: The motivation behind this study stems from the urgent need to decipher the neuroinflammatory processes contributing to Post-Acute Sequelae of COVID-19 (PASC) and to identify potential biomarkers for this condition through neuroimaging.

Goal(s): The primary goal is to investigate the presence of cerebral imaging markers indicative of neuroinflammation in individuals experiencing neurological PASC.

Approach: The study employed multi-shell diffusion MRI, to investigate changes in individuals with PASC. Diffusion parameters indicative of neuroinflammation were analyzed, by comparing among PASC patients, never-infected individuals, and acute-COVID controls.

Results: PASC patients demonstrated increased whole-brain alterations consistent with axonal injury with inflammation. 

Impact: The findings of altered diffusion parameters in PASC patients shed light on the presence of axonal injuries with inflammation. These insights can potentially impact the diagnosing and treating long-term neurological symptoms of COVID-19, ultimately improving patient care and recovery strategies.

Keywords: Functional Connectivity, COVID-19

Motivation: Neural functional networks provide insights into the intrinsic function and integrity of brain areas.

Goal(s): The aim of the current study was to investigate the levels of functional integration and segregation of brain areas within the default mode network (DMN) in a cohort of adults 6-12 months after admission for SARS-CoV-2 pneumonia.

Approach: We used a functional atlas and graph-theoretical framework to model the topology of brain areas within the DMN.

Results: We found reduced functional integration within the DMN of adults previously admitted with SARS-CoV-2. Affected brain areas are involved in higher-cognitive memory processing functions.

Impact: Investigating the brain’s functional organization in the context of post-acute infection with SARS-CoV-2 can offer a window into the neuropathology of long COVID-19 symptoms.

Keywords: Infectious Disease, COVID-19, Synthetic MR, Quantitative Imaging, Data Analysis, Voxel-wise Analysis, Voxel-based Analysis

Motivation: The effect of COVID-19 on the brain is not fully understood. Simultaneous 3D-acquisition of relaxometry parameters can indicate where microstructure has changed.

Goal(s): To locate differences in T1, T2 and proton density in COVID-19 patients.

Approach: 3D-QALAS was performed on 17 volunteers and 17 patients. Relaxometry and segmentation maps were calculated and warped to a common space to compare both groups.

Results: T2 changes associated with COVID-19 were observed in left cerebellar white and grey matter and in WM of the brain stem and thalamus, along with increased right temporal and occipital T1 and PD, and decreased frontal T1, T2 and PD values.

Impact: A voxel-based relaxometry analysis using 3D-QALAS data, including WM and PD, was performed for the first time, based on the hMRI toolbox. Different patterns of parameter changes were observed in several brain regions, possibly indicating different types of microstructural changes.
 

Keywords: Blood Vessels, Brain

Motivation: Recent developments enabled to measure brain tissue strain as induced by arterial pulsations in detail. This opens the opportunity to study how these strains are affected by the brain’s macroscopic environment and its local microstructure.

Goal(s): To explore to what extent the strain principal strain directions can be explained by both global boundary conditions and local tissue microstructure.

Approach: Systolic 3D strain measurements of the brain were compared with a brain model and DTI measurements.

Results: The first principal strain showed good agreement with the brain model and consistent spatial patterns were observed in comparisons between third principal strain and DTI data.

Impact: Our results help confirm previous ideas on how the brain swells during cerebral arterial pulsations while also providing a first view into the relationship between the direction of the Poisson effect and brain microstructure, opening up avenues for further research.

Keywords: Blood Vessels, Susceptibility, echo combination, multi-echo

Motivation: Scan times for multi-echo T₂^*w sequences are too long at 1.5T.

Goal(s): Shorten scan times by reducing the number of echoes needed for a specific contrast.

Approach: During this ISMRM, we introduced a novel echo combination method that increases contrast over the standard Root Sum-of-Squares (RSOS) technique. We applied this method to 7 and 6 echo 3D SPGR protocols and compared the results to a 9 echo protocol that used RSOS.

Results: Contrast was comparable or better in the 6 and 7 echo protocols using our technique, compared to the 9 echo protocol with RSOS, resulting in a scan time reduction of 23-26%.

Impact: Our echo combination technique allows fewer echoes in multi-echo T₂^*w imaging to match the contrast of higher echo protocols resulting in a 23-26% scan time reduction. This alleviates one of the primary concerns clinicians have using T₂^*w imaging at 1.5T.

Keywords: Blood Vessels, Perfusion, Small vessel disease

Motivation: Largely unidentified pathophysiological mechanisms in cerebral small vessel disease (cSVD) hamper treatment development. One of the potentially affected functions is cerebral blood flow (CBF) autoregulation.

Goal(s): Establish whether brain tissue perfusion is (in)dependent of macrovascular blood supply in cSVD patients.

Approach: The relationship between internal carotid artery blood flow (blood supply), measured with phase-contrast MRI, and gray matter CBF (CBF_GM), measured with arterial spin labeling, was determined separately for cSVD patients (n=41) and controls (n=18).

Results: A significant, positive relationship between CBF_GM and blood supply was found in cSVD patients, but not in controls, suggesting impaired autoregulation in cSVD.

Impact: We revealed a positive relationship between internal carotid artery blood supply and the cerebral blood flow in gray matter in cerebral small vessel disease patients, but not in controls, which could indicate compromised autoregulatory capacity.

Keywords: Blood Vessels, Blood vessels, 4D Flow

Motivation: To investigate the relationship between the enhancement of intracranial cystic aneurysm walls and aneurysm morphology and hemodynamics. 

Goal(s): The study aimed to identify new imaging indicators for intracranial aneurysm enhancement.

Approach: We conducted a retrospective collection of magnetic resonance images of aneurysm cases and grouped them based on aneurysm wall enhancement grades. Then the differences in morphological and hemodynamic parameters between groups were compared.

Results: The study found that the maximum flow rate at the aneurysm neck and the ratio of the aneurysm neck to the maximum flow rate of the parent artery were statistically significant.

Impact: This study investigated the hemodynamic relationship between aneurysms and the parent artery, and its potential impact on aneurysm wall enhancement. These results could offer valuable insights into the connection between aneurysm wall enhancement and hemodynamics.

Keywords: Blood Vessels, Animals, The glymphatic system

Motivation: The pathogenesis of hypertensive cerebral edema remains elusive

Goal(s): To visualize and evaluate the transport function of the glymphatic system in the spontaneously hypertensive rats (SHR).

Approach: We used the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and immunofluorescence analysis

Results: And we found that there was a significant change in the transport function of the glymphatic system and a decrease in the expression of aquaporin-4 (AQP4) around blood vessels. 

Impact: The combination of DCE-MRI and immunofluorescenc analysis can facilitate further exploration of mechanisms underlying brain edema in the spontaneously hypertensive animal models, thus aiding in the study of the glymphatic system.

Keywords: Blood Vessels, Diffusion Tensor Imaging, cerebral small vessel disease; glymphatic clearance function; ALPS index; SVD score

Motivation: The pathogenesis of cerebral small vessel disease (SVD) is unclear, which may be related to glymphatic clearance.

Goal(s): To assess the association between glymphatic clearance function and the extent of cerebral damage in SVD, along with the effects on cognitive function.

Approach: We derived the ALPS index from DTI data to evaluate lymphatic function, and we utilized MR imaging to determine the SVD score as a measure of cognitive function.

Results: We found a significantly decrease in ALPS index in SVD patients compared to healthy controls, and a significantly negative correlation between the ALPS index in the left hemisphere and SVD severity.

Impact: Glymphatic clearance dysfunction may be present in patients with SVD and may be associated with decreased cognitive function.

Keywords: Blood Vessels, Velocity & Flow

Motivation: The hemodynamic changes after superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with Moyamoya disease (MMD) remain unclear. 4D flow is expected to provide more information about the hemodynamic parameters of patients with MMD before and after surgery.

Goal(s): To clarify the hemodynamics by comparing flow parameters obtained by 4D flow magnetic resonance imaging (MRI).

Approach: Patients with MMD were prospectively recruited for 4D flow magnetic resonance scanning before and after bypass surgery.

Results: After bypass surgery, the contralateral internal carotid artery blood flow decreased and cerebral blood flow was redistributed.

Impact: The results indicate that 4D flow MRI is a feasible, noninvasive alternative for evaluating bypass grafts in the early postoperative period. These flow parameter values may help improve the way patients are evaluated after bypass surgery.

Keywords: Blood Vessels, Brain, 7T-CEST

Motivation: The incidence of middle cerebral arterial (MCA) stenosis increases yearly, molecular biomarkers for this condition are needed. Amide proton transfer imaging is a potential imaging marker. 

Goal(s): To investigate the APT changes in MCA stenosis patients.

Approach: We quantitatively evaluated both the affected and healthy middle cerebral arterial blood-supplying brain regions in eight patients with unilateral middle cerebral arterial stenosis using CEST-APT at 7T. 

Results: The CEST values of the affected MCA-supplied brain regions were higher than those of the healthy MCA-supplied brain regions, suggesting metabolic alterations in patients with MCA stenosis.

Impact: CEST values for vascularized brain regions can be quantitatively measured using 7T-CEST and can provide new markers for mechanistic and intervention studies in patients with MCA stenosis. This can contribute to a better understanding of the pathogenesis of MCA stenosis.

Keywords: Blood Vessels, fMRI (resting state), cerebrovascular reactivity

Motivation: Mapping of cerebrovascular reactivity (CVR) using resting-state BOLD fMRI (RS-fMRI) was raised in 2017 and 2021 with verification using the moyamoya disease (MD). But pathological hemodynamics of MD was missing by RS-fMRI.

Goal(s): Arterial stealing phenomenon can be demonstrated by carbogen-based fMRI (CO2-CVR), but not by RS-fMRI.

Approach: Both RS-CVR and CO2-CVR using a 3T MR and an automatic delivery system of carbogens were acquired for eleven subjects and ten patients with MD. Bland-Altman plots was applied for both RS-CVR and CO2-CVR.

Results: By using CO2-CVR, unique negative CVR of MD verified the arterial stealing phenomenon which was missed by RS-CVR.

Impact: Arterial stealing phenomenon of moyamoya disease/syndrome can be demonstrated as negative cerebrovascular reactivity by carbogen-based fMRI (CO2-CVR), but not by resting-state fMRI (RS-CVR).

Keywords: Vascular, Stroke

Motivation: Stroke is major global cause of death. However markers of recovery are still lacking. 

Goal(s): Vasculature affects shear waves propagation acting as a scattering source, ultimately affecting waves dispersion properties measurable with MRE.

Approach: In this study we use multi frequency MRE to find the fingerprint of vascular remodelling after stroke in the dispersion properties of waves, and explored the temporal profile of vascular and tissue remodelling and its relashionship with recovery.

Results: We show for the first time in-vivo that MRE senses tissue integrity as well as vascular organization. We show that such parameters have a good prognostic value.

Impact:   We show that MRE could disentangle tissue constitutive properties and vasculature, and thereby could provide new insights in the understanding of tissue plasticity after stroke and potentially constitute a relevant marker in the context of stroke therapy.

Keywords: Blood Vessels, White Matter

Motivation:  Cardiovascular disease (CVD) is closely related to cerebrovascular injury. However, even when the ejection fraction (EF) is normal, the cardiac microvascular system may still be abnormal.

Goal(s): Explore the relationship between CVD with preserved EF and cerebrovascular injury.

Approach: The heart and brain MRI of the participants were scanned with 3.0T MRI scanner. Different cardiac ejection parameters and high signal images of white matter were obtained.

Results: Patients with CVD, when EF is normal, are still associated with WMH and are still a risk factor for brain injury.

Impact: t is crucial to pay early attention to the early indicators of cerebrovascular abnormalities in patients with heart failure, as timely intervention is essential for reducing the risk of stroke.

Keywords: Blood Vessels, Blood vessels, Microvasculature mapping, vascular abnormalities

Motivation: There is limited understanding of microvascular alterations in neurovascular diseases such as multiple sclerosis (MS) and Parkinson’s disease (PD) using in vivo imaging techniques.

Goal(s): To detect microvascular abnormalities using the novel imaging technique MICRO (Microvascular In-vivo Contrast Revealed Origins).

Approach: MICRO imaging involves high resolution susceptibility weighted imaging (SWI) acquired in the presence of ultrasmall superparamagnetic iron oxides (USPIO). 

Results: As compared to non-contrast conventional vascular imaging, MICRO drastically improves the detection of microvascular abnormalities that can help in identifying the most vulnerable structures in vascular etiology of MS and PD.

Impact: This multicentre study demonstrates that MICRO imaging has the potential to comprehensively study vascular pathology something that is often ignored in evaluating neurodegenerative diseases. 

Keywords: Blood Vessels, Velocity & Flow, ASL

Motivation: Hemodynamic information in the posterior circulation of Moyamoya disease (MMD) patient is crucial and may hint collateral flow.

Goal(s): To assess feasibility of hemodynamic quantification for the posterior circulation of MMD patients based on ASL dynamic MRA.

Approach: The model-free aBF quantification method based on ASL dynamic MRA,  CFD simulation and 3D phase contrast (PC) were compared in the posterior circulation and the circle of Willis.

Results: As compared to CFD, aBF demonstrated better an agreement with PC results and had the potential for quantifying distal vessels. However, its accuracy may be influenced by the choice of AIF.

Impact: This study provides preliminary evidence regarding the feasibility of using ASL dynamic MRA to quantify the flow hemodynamics in Moyamoya disease patients.

Keywords: Blood Vessels, Blood vessels, BOLD dynamic susceptibility contrast

Motivation: Heterogenous BOLD responses are expected across brain regions due to different baseline blood volumes. However, there are very few experimental data to show regional differences of ΔR₂^*.

Goal(s): To determine regional ΔR₂^* by graded hypoxia and to elucidate field dependency of regional ΔR₂^* to transient hypoxic stimuli.

Approach: Three hypoxic conditions (90%N₂, 95%N₂, 100%N₂) were administered to anesthetized mice in two different magnetic field strengths of 9.4T and 15.2T.

Results: The peak ΔR₂^* map revealed heterogenous BOLD responses across regions. Field-dependent ΔR₂^* ratio to 15.2T to 9.4T is close to the ratio of the magnetic field strengths.

Impact: We quantitatively determined regional BOLD responses in whole brain to hypoxia, which is dependent on baseline blood volume. Our result can serve as reference data for normalizing sensitivity of BOLD responses evoked by neuronal activity or vascular stimuli across regions.

Keywords: Blood Vessels, fMRI (task based), Neurovascular coupling

Motivation: We aimed to unravel the intricate relationship between neuronal metrics and vascularization in human visual cortex, addressing the need for a deeper understanding of these factors' impact on fMRI data.

Goal(s): Our study sought to determine if differences exist in pRF sizes between micro- and macro-vascular compartments and the influence of extra- and intra-vascular effects.

Approach: We obtained pRF estimates across cortical depth using different fMRI scan sequences (SE/GE) at varying field strengths (7T/3T).

Results: While our findings confirmed typical pRF size trends and vascularization-dependent amplitude effects across cortical depth, we did not find that vascularization or magnetic field strength affected pRF sizes.

Impact: This study's findings challenge the conventional understanding of how vascularization affects neuronal metrics in functional brain imaging. The research underscores the complexity of neurovascular interactions and their implications for the interpretation of fMRI data.

Keywords: Blood Vessels, Alzheimer's Disease, White Matter; Velocity & Flow

Motivation: This study is driven by the need to understand the intricate relationship between cerebrovascular disease (CVD) and Alzheimer's disease (AD) pathology.

Goal(s): In this study, we aim to investigate the correlations between CVD markers, AD biomarkers and white matter (WM) microstructure.

Approach: To achieve these goals, we used 4D flow MRI and neurite orientation dispersion and density imaging (NODDI) and utilized statistical models to examine the relationships between vascular flow and WM neurite density index. 

Results: Our results identified significant correlations between AD biomarkers, WM integrity and cerebrovascular flow in specific vessels. 

Impact: Our findings motivate further investigations into the intricate relationship between cerebrovascular disease and Alzheimer's disease (AD) pathology. Better understanding of this relationship may improve early AD detection and therapeutic strategies. 

Keywords: Blood Vessels, Neurofluids, respiratory effects, CBF, cerebral blood flow, phase contrast, real time phase contrast

Motivation: The hydrodynamic characteristics of arterial venous cerebral blood flow (AVCBF) in different breathing patterns remain insufficiently understood.

Goal(s): Quantifying the effects of free and deep breathing on multiple parameters of CBF using real-time phase contrast MRI.

Approach: We applied RT-PC on 14 healthy volunteers to continuously quantify AVCBF dynamics in the main cerebral vessels during free and deep breathing. A time-domain analysis investigated the influence of breathing change on the AVCBF parameters: mean flow, stroke volume, cardiac period.

Results: Deep-breathing decreased global AVCBF dynamics. Mean flows, stroke volumes and cardiac periods decreased but their percentage change between inspiratory and expiratory periods increased.

Impact: This study quantified the effects of free- and deep-breathing on cerebral blood flow dynamics. It should contribute to a better understanding of cerebral hemodynamics and its relation with breathing, providing a valuable reference for clinical applications and physiological studies.

Keywords: Blood Vessels, CEST & MT, Cerebrovascular disease

Motivation: Assessing alterations of the brain microenvironment in patients with moyamoya disease after revascularization (MMD) would develop optimal postoperative management and improve the prognosis.

Goal(s): This study aimed to explore alterations of amide proton transfer weighted (APTw) signal in patients with MMD after receiving revascularization surgery.

Approach: MMD patients who underwent unilateral revascularization surgery were prospectively collected. Baseline computed tomography perfusion (CTP) and APTw imaging were performed. Patients were followed up with CTP and APTw imaging about 1 year after revascularization.

Results: APTw values in both surgical and contralateral hemispheres at follow-up were found to be significantly higher than those at baseline.

Impact: APTw imaging is a potential assessment tool to quantitatively evaluate alterations of acid-base metabolism in the brain microenvironment of patients with MMD after revascularization, which provides additional information to help neurosurgeons develop optimal postoperative management and follow-up protocols for MMD.

Keywords: Blood Vessels, Velocity & Flow, Cerebrovascular disease, moyamoya angiopathy

Motivation: Current evidence is insufficient to help better understand the interactions between hemodynamics of carotid siphons in moyamoya angiopathy (MMA) and outcomes of revascularization.

Goal(s): To evaluate hemodynamic alterations of carotid siphons after revascularization for MMA using 4D Flow MRI and to explore its association with outcomes.

Approach: MMA patients receiving revascularization were prospectively enrolled. We used VesselExplorer2 software to analyze 4D Flow MRI data and measure hemodynamic parameters of carotid siphons. Relationships between hemodynamic parameters of carotid siphons and surgical outcomes were explored.

Results: Flow_mean and Flow_max of bilateral ICAs in MMA decreased at follow-up, which was associated with outcomes of revascularization surgery.

Impact: We identified new hemodynamic parameters that might be used to predict the prognosis of MMA. 4D Flow MRI is a promising tool for quantitatively detecting hemodynamics in intracranial vessels of MMA patients, providing valuable hemodynamic parameters for evaluating surgical outcomes.

Keywords: Blood Vessels, Modelling

Motivation: MRI is increasingly used to investigate vascular pathology in neurodegenerative disease. The origin of the MRI signal, however, often remains elusive. This study models pulsatile blood flow aiming to characterize vascular pulsation’s impact on MRI signal formation in advanced sequences.

Goal(s): To create a realistic model of pulsatile blood flow in microvasculature.

Approach: Static and pulsatile flow are simulated in a simplified and a more realistic synthetically generated vessel model using 1D approximations of governing equations.

Results: Pulsatile flow simulations in simplified networks with realistic inflow wave forms yield realistic deformation characteristics. Realistic pressure and flow distributions are achieved in extensive microvascular networks.

Impact: By providing realistic voxel-scale vascular simulation models capable of quantifying physiological parameters such as CBV and vessel deformation due to pulsatility, contribution of microvascular pulsations to MRI signal and cerebral waste clearance may be explored in the future.

Keywords: Blood Vessels, Stroke, Acute ischemic stroke,Multimodal Scan,Time Efficiency

Motivation: The matter of time efficiency for both CT and MRI remains a topic of ongoing debate.

Goal(s): To provide an objective comparison of time efficiency between CT multimodal and MRI multimodal scans in patients with acute ischemic stroke in the late time window.

Approach: Efficiency in terms of time was compared between AIS patients who underwent CT scans and those who underwent MRI scans.

Results: The evaluation time for the MRI multimodal scan was found to be shorter than that of CT. MRI scans were recommended for use during the night shift. Furthermore, more experienced technicians had shorter scanning times.

Impact: Implementing this approach can streamline the scanning procedure for radiology departments when dealing with acute stroke patients, aid in the training of technicians, and recommend a preference for MRI scans during nighttime shifts.

Keywords: Blood Vessels, Neurodegeneration, Cerebral Small Vessel Disease

Motivation: The motivation behind this study was to delve deeper into the amygdala subregion changes in Cerebral Small Vessel Disease (CSVD) and how these changes correlate with cognitive impairment.

Goal(s): The primary goal was to determine whether specific amygdala subregions could serve as early indicator for cognitive impairment in CSVD, thereby aiding in early diagnosis and intervention.

Approach: Combined 3T MRI neuroimaging with cognitive assessments and focused statistical evaluation of amygdala subregions

Results: Our study revealed significant volume reductions in specific amygdala subregions among CSVD group, with pronounced atrophy observed in the left cortical nucleus.

Impact: This research introduces a novel indicator that utilizes neuroimaging techniques for the early prediction of CSVD progression and associated cognitive impairment, which could significantly enhance the precision of diagnostics and inform effective management strategies for CSVD.