Quantitative spinal cord MRI in radiologically isolated syndrome

Abstract

ObjectivesTo assess whether quantitative spinal cord MRI (SC-MRI) measures, including atrophy, and diffusion tensor imaging (DTI) and magnetization transfer imaging metrics were different in radiologically isolated syndrome (RIS) vs healthy controls (HCs).MethodsTwenty-four participants with RIS and 14 HCs underwent cervical SC-MRI on a 3T magnet. Manually segmented regions of interest circumscribing the spinal cord cross-sectional area (SC-CSA) between C3 and C4 were used to extract SC-CSA, fractional anisotropy, mean, perpendicular, and parallel diffusivity (MD, λ⊥, and λ||) and magnetization transfer ratio (MTR). Spinal cord (SC) lesions, SC gray matter (GM), and SC white matter (WM) areas were also manually segmented. Multivariable linear regression was performed to evaluate differences in SC-MRI measures in RIS vs HCs, while controlling for age and sex.ResultsIn this cross-sectional study of participants with RIS, 71% had lesions in the cervical SC. Of quantitative SC-MRI metrics, spinal cord MTR showed a trend toward being lower in RIS vs HCs (p = 0.06), and there was already evidence of brain atrophy (p = 0.05). There were no significant differences in SC-DTI metrics, GM, WM, or CSA between RIS and HCs.ConclusionThe SC demonstrates minimal microstructural changes suggestive of demyelination and inflammation in RIS. These findings are in contrast to established MS and raise the possibility that the SC may play an important role in triggering clinical symptomatology in MS. Prospective follow-up of this cohort will provide additional insights into the role the SC plays in the complex sequence of events related to MS disease initiation and progression.

Considerations for Mean Upper Cervical Cord Area Implementation in a Longitudinal MRI Setting: Methods, Interrater Reliability, and MRI Quality Control

“…1,4,5 One of the most common SC atrophy measurement methods is the mean upper cervical cord area (MUCCA). [6][7][8] MUCCA has been found to be robust at the C1-C2 and C2-C3 intervertebral levels. 9,10 However, there is little consensus on how reliable it is longitudinally or whether SC atrophy measures are ready for use as a clinical trial end point and/or for patient monitoring in neuroinflammatory diseases, 11,12 SC injury, 13,14 or degenerative cervical myelopathy, 15 among other diseases affecting the SC.…”

“…29 This method was shown to better segment MR imaging scans, including the brain, than PropSeg; however, raw MUCCAs were still significantly different between DeepSeg and Jim. 7 Thus, when one compares results from different studies using different segmentation methods, absolute MUCCA cannot be used; rather, we propose the evaluation of effect sizes from the change in the MUCCA from each study.…”

Differences in Advanced Magnetic Resonance Imaging in MOG-IgG and AQP4-IgG Seropositive Neuromyelitis Optica Spectrum Disorders: A Comparative Study

“…MOG-IgG seropositive patients with clinical and neuroimaging features of NMOSD are currently under discussion as being a distinct disease entity (45)(46)(47)(48)(49)(50)(51). There are few studies investigating MRI findings of MOG-IgG+ patients, likely due to its recent discovery and rare prevalence (18,28,(46)(47)(48).…”

“…While brain atrophy and microstructural tissue damage occur in MS from earliest disease stages (28)(29)(30), non-conventional MRI studies have shown conflicting results in NMOSD (31)(32)(33)(34)(35), and advanced imaging, such as diffusion tensor imaging (DTI) analysis, have not been reported from MOG-IgG+ patients.…”

Radiologically Isolated Syndrome: A Review for Neuroradiologists

“…Similar changes were reported in advanced MR imaging of the spinal cord in RIS. In a study 22 of 3T spinal cord MR imaging in 24 individuals with RIS and 14 healthy controls, the spinal cord magnetization transfer ratios were lower in patients with RIS. By contrast, there were no significant differences in the DTI metrics (fractional anisotropy and mean, perpendicular, and parallel diffusivity) between individuals with RIS and healthy controls.…”