Relative Clinical Utility of Quantitative MRI Measures in the Spinal Cord in Multiple Sclerosis Patients (PD6.006)

OBJECTIVE: To determine which combination of quantitative MRI measures in the spinal cord(SC) is best able to discriminate between multiple sclerosis(MS) patients of differing disability levels. BACKGROUND: SC pathology is common in MS. Prior studies have shown that quantitative MRI measures in the SC, including diffusion-tensor and magnetization-transfer imaging derived indices, and SC-cross-sectional area(CSA), correlate with MS-related clinical disability. The relative clinical utility of these MRI measures is unclear, and certain MRI measures may be more adept at discriminating between disability levels in MS patients than others. DESIGN/METHODS: 124 MS patients underwent 3-tesla cervical SC-MRI and were categorized into subgroups based on expanded disability status scale(EDSS) score and SC lesion count. Regions-of-interest circumscribed the SC cross-section axially between C3-C4. SC-CSA, fractional anisotropy(FA), mean diffusivity(MD), perpendicular/parallel diffusivity(λA5;/λ||), and magnetization-transfer ratio(MTR) were calculated. To determine which combination of MRI measures would best associate with disability level, a multivariable logistic regression model using forward stepwise selection(p-value cut-off=0.10) was utilized with disability level as the dependent variable and MRI measures, age, and sex included as potential covariates. RESULTS: In all MS patients, the covariates of age, sex, SC-CSA,FA, and MTR(p CONCLUSIONS: The combination of SC-CSA, FA, and MTR was best able to discriminate between disability levels in MS patients, suggesting that certain combinations of MRI measures may be of more predictive clinical utility than others. The clinical discriminatory ability of combinations of MRI measures differs in settings of low/high lesion counts. Prospective studies are needed to assess the prognostic utility of these MRI measures in predicting disability progression, which would broaden the clinical application of these imaging techniques. Supported by: MS Society of Canada; National MS Society. Disclosure: Dr. Oh has received research support from Teva Neuroscience and EMD Serono. Dr. Saidha has received personal compensation for activities with MedicalLogix and Teva Neurosciences. Dr. Chen has nothing to disclose. Dr. Smith has nothing to disclose. Dr. Prince has received personal compensation for activities with Diagnosoft, Inc. Dr. Prince has received royalty payments from technology that Johns Hopkins owns and has licensed to Diagnosoft, Inc. Dr. Prince holds stock and/or stock options in Diagnosoft, Inc. Dr. Jones has received research support from Philips Medical Systems. Dr. Van Zijl has received personal compensation for activities with Philips Medical Systems and Kennedy Krieger Institute as speaker and/or consultant. Dr. Van Zijl has received research support from Philips Medical Systems. Dr. Diener-West has nothing to disclose. Dr. Reich has nothing to disclose. Dr. Calabresi has received personal compensation for activities with Biogen Idec, Teva Neuroscience, Genzyme Corporation, Vaccinex, Vertex, and Novartis. Dr. Calabresi has received research support from the National Institutes of Health, the National Multiple Sclerosis Society, Nancy Davis Foundation, Biogen Idec, Vertex, Genentech, Inc., Abbott, and Bayer.