4473
Comparison of 5T and 3T MRI in patients with moyamoya disease: An initial study
Sirui Li1, Mengqi Tu1, Dan Xu1, Shihong Han2, Shuheng Zhang2, Wenbo Sun1, Jinchao Chen3, Haibo Xu1, and Jianjian Zhang3
1Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China, 2United Imaging Healthcare, Shanghai, China, 3Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan, China
1Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China, 2United Imaging Healthcare, Shanghai, China, 3Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan, China
Synopsis
In this study, a 5.0T whole body MR imaging system was used for the evaluation of moyamoya disease (MMD). Diagnostic performance of time-of-flight magnetic resonance angiography (TOF-MRA) and susceptibility-weighted imaging (SWI) were evaluated and compared between the 5T MRI scanner and a clinical 3T MRI scanner in three MMD patients. Preliminary results show that 5 T MRI might be superior to 3T MRI for the visualization of small collateral branches and micro bleeding points.
Introduction
Moyamoya disease (MMD) is a serious cerebrovascular disease with progressive stenosis and occlusion of the main trunk of the internal cerebral arteries, which is accompanied by the development of small collateral branches in the basal ganglia.1,2 Magnetic resonance imaging (MRI) is a valuable imaging tool for the non-invasive assessments of seventy of MMD.3 However, Due to the complex architecture and hemodynamic features of collateral networks, MRI has limitations in the visualization of small collateral branches with slow flow in MMD at 3T.3 The developed ultra-high field (7T) MRI has already changed this situation, which has been proven comparable to the digital subtraction angiography (DSA).2 Recently, a 5T whole body MR imaging system was developed,4 and its performance for the clinical use has not been reported yet. This study aimed to compare the performance of the high-resolution time of flight MR angiograph (TOF-MRA) and susceptibility-weighted imaging (SWI) sequences in imaging MMD between a clinical 3T MRI scanner and the 5T whole body MRI.Methods
Three MMD patients were enrolled and the written informed consent was successfully acquired. Before the DSA, conventional MRI examinations were performed on a clinical 3T scanner (uMR 790, United Imaging Healthcare, Shanghai, China) with a commercial 24-channel phased-array head-neck coil, including high resolution TOF-MRA (TR/TE = 20/4.5ms, BW = 230Hz, thickness=0.25mm, matrix =383*464, Fov = 190*230mm2) and SWI (TR/TE = 32/19 ms, BW = 110Hz, thickness=0.75mm, matrix =525*624, Fov = 185*220mm2) scans. Within the same day, MRI examinations with the same resolution were performed again on a whole body 5T scanner (uMR Jupiter, United Imaging Healthcare, Shanghai, China) with a customized 48-channel phased-array head coil, including TOF-MRA (TR/TE = 20/4 ms, BW = 210Hz, thickness=0.25mm, matrix =383*464, Fov = 190*230mm2) and SWI (TR/TE = 32/19 ms, BW = 110Hz, thickness=0.75mm, matrix =525*624, Fov = 185*220mm2). Images acquired at both 3T and 5T MRI were compared in terms of SNR and contrast. The diagnostic performace of TOF-MRA and SWI measurements in MMD at 5T MRI were evaluated.Results
Compared with the conventional 3T MRI, the TOF-MRA sequence performed at 5 T MRI demonstrates high SNR and better contrast, especially when showing small collateral branches in the basal ganglia (Figure 1), and in the cortex (Figure 2) . The SWI sequence at 5T also shows high SNR compared with SWI at 3T (Figure 3). Besides, the SWI enhanced the visualization of intracranial vein and micro bleeding points of hemorrhagic MMD, as showed in Figure 3. In addition, a fusion of the TOF-MRA and SWI images simultaneously visualized the intracranial arteries and veins of MMD, as showed in Figure 4.Discussion
The visualized of collateral branches and micro bleeding points is very important for the revascularization surgery of MMD patients.2 The preliminary results in this study have showed 5T MRI is a very promising tool for evaluating MMD with routine TOF-MRA and SWI sequences, superior to 3T, and similar with findings at 7T.1-3 Besides, the fusion of TOF-MRA and SWI provide a new constrast for MMD, which will help the surgical planning of the superficial-temporal-artery—middle-cerebral-artery (STA-MCA) bypass and the postoperative evaluation.In the future, more MMD patients will be enrolled in this study and more quantitative results will be given to uncover benefits at 5T. Besides, a comparison 5T TOF-MRA with the DSA is on the way.Conclusion
A new 5.0T whole body MR imaging system might be a very promising tool for the assessments of MMD in clinic.Acknowledgements
This work is supported by National Key R&D Program of China 2017YFC0108803.References
1.Deng X, Zhang Z, Zhang Y, Zhang D, Wang R, Ye X, Xu L, Wang B, Wang K, Zhao J. Comparison of 7.0- and 3.0-T MRI and MRA in ischemic-type moyamoya disease: preliminary experience. J Neurosurg. 2016 Jun;124(6):1716-25.
2. Matsushige T, Kraemer M, Sato T, Berlit P, Forsting M, Ladd ME, Jabbarli R, Sure U, Khan N, Schlamann M, Wrede KH. Visualization and Classification of Deeply Seated Collateral Networks in Moyamoya Angiopathy with 7T MRI. AJNR Am J Neuroradiol. 2018 Jul;39(7):1248-1254.
3. Su J, Ni W, Yang B, Xiao W, Gao X, Yang H, Li Y, Lei Y, Jiang H, Wang H, Gu Y, Mao Y. Preliminary Study on the Application of Ultrahigh Field Magnetic Resonance in Moyamoya Disease. Oxid Med Cell Longev. 2021 Jan 13;2021:5653948.
4. Zhenhua Shen, Xuchen Zhu, Shihong Han, et al. Initial Experience of Body Imaging at 5T. ISMRM 2021;3120.
Figures
Figure1.
an example of the comparison of the TOF-MRA sequences between the 5T (left row) and
the 3T (right row) in the basal ganglia. The 5.0T MRI gives more detailed information
of vascular anatomy. The a1 and a2 represent the TOF-MRA images of a 40 years old
male at 5T and 3T, respectively. The b1 and b2 represent the TOF-MRA images of a 59 years old
female. The c1 and c2 represent the TOF-MRA images of a 50 years old female.
Figure2.
an example of the comparison of the TOF-MRA sequences between the 5T (a) and
the 3T (b) at the cortex. The 5.0T MRI gives more detailed information of vascular
anatomy of MMD patients.
Figure3. an example of the comparison of the SWI sequence between the 5T (a) and the 3T (b) in the basal ganglia of a 59 years old female MMD patients with micro-hemorrhage. The 5T SWI obviously has higher SNR and better contrast than the 3T.
Figure4. an illustrations of the fusion images of TOF-MRA and SWI sequences showed the micro-hemorrhage of one MMD patients at 5T (a-c), and the fusion of the TOF-MRA and SWI clearly showed the micro bleeding points (the white arrow).
DOI: https://doi.org/10.58530/2022/4473