Introduction

Lesions can occur within the spinal cord in various conditions such as demyelination, infection, trauma, tumour, infarction, cord compression etc. Accurate diagnosis is critical for appropriate therapeutic management and clinical outcome. T2 weighted turbo spin echo (T2 TSE) is one of the standard and primary techniques used for lesion assessment in the spinal cord.^1,2 In the recent past white matter suppressed (wms) T1 weighted TSE sequence, also referred to as T1 STIR (short tau inversion recovery), has been shown to be better than the conventional sequences in better conspicuity in spinal lesion detection in Multiple sclerosis.³ However, reports on its applicability in non-MS spinal conditions are scant. In this work we have applied wms T1 STIR in cases of spinal conditions other than MS, to explore its relevance in these conditions.

Materials and Methods

WMS T1 STIR data was acquired in 4 patients with different spinal conditions – spinal infarction, trauma post infective transverse myelitis and ADEM (acute disseminated encephalomyelitis) (see Table-1 for imaging parameters) in addition to the conventional spine imaging protocol. In one of the patients, with ADEM, data was acquired at two time points, 10 weeks apart – pre-treatment and post-treatment. Another patient, with spinal infarction was also imaged twice – 1 day apart. WMS T1 STIR images were compared with the conventional T2 TSE sagittal and/or T2 TSE axial for the visualization of lesion and artifacts.

Results

Figures 1 to 4 compare the visualization of lesions in the cases of infarction, post infective transverse myelitis, ADEM, and spinal trauma respectively. Conspicuity of the lesions was better in WMS T1 STIR compared to the conventional T2 TSE. In the ADEM case, the effect of treatment was more clearly visualized with WMS T1 STIR compared to T2 TSE.

Discussion and Conclusion

Use of IR sequence in detecting white matter lesions of brain is well established with sequences developed to suppress CSF like FLAIR as well as white mater in Double IR sequences with 3D acquisitions to better depict various white mater lesions and hence characterize disease burden.1 A good spectrum of such conditions also involve spinal cord; lesions of which have always been a challenge to pick up employing conventional sequences like T2 weighted image owing to acquisition related parameters, artefacts and inter-reader variability in lesion count.4 As gray mater forms a significantly smaller component (by volume) of cord parenchyma, with negligible inherent differentiation between gray and white mater of spinal cord; it seems sufficient to employ a sequence with selective white mater suppression to depict lesions in spine, even in non-MS conditions. Differentiation between various conditions involving cord parenchyma is of extreme clinical importance as management decisions vary impacting clinical outcome. For example, differentiation between a hyperacute condition like spinal cord infarct from more treatable condition like demyelination implies different treatment regimens and prognosis. It is also important to characterize type of lesion for differentiating various demyelinating diseases like MS, NMO and ADEM; treatment of which are quite different and could even potentially worsen existing condition as in NMO if treated with interferon beta which is used to treat MS. Also depiction of lesion response to treatment, development of new lesions can independently influence treatment modifications on follow up. In this context, better conspicuity of lesions, offered by WMS T1 STIR is desirable and could be either used as an adjunct to T2 weighted image or as a standalone sequence. The present study is a preliminary work in exploring the relevance of WMS T1 STIR in non-MS spinal conditions. While the results are promising, application in a larger cohort is warranted for statistically establishing its utility.

Acknowledgements

No acknowledgement found.

References

1. Americal College of Radiology. ACR–ASNR–SCBT-MR–SSR PRACTICE PARAMETER FOR THE PERFORMANCE OF MAGNETIC RESONANCE IMAGING (MRI) OF THE ADULT SPINE.; 2018. 2. Simon JH, Li D, Traboulsee A, et al. Standardized MR imaging protocol for multiple sclerosis: Consortium of MS Centers consensus guidelines. In: American Journal of Neuroradiology. ; 2006. doi:27/2/455 [pii] 3. Poonawalla AH, Hou P, Nelson FA, Wolinsky JS, Narayana PA. Cervical Spinal Cord Lesions in Multiple Sclerosis: T1-weighted Inversion-Recovery MR Imaging with Phase-Sensitive Reconstruction. Radiology. 2008. doi:10.1148/radiol.2463061900 4. Altay EE, Fisher E, Jones SE, Hara-Cleaver C, Lee JC, Rudick RA. Reliability of classifying multiple sclerosis disease activity using magnetic resonance imaging in a multiple sclerosis clinic. JAMA Neurol. 2013. doi:10.1001/2013.jamaneurol.211