Abstract: Relative Clinical Utility Of Quantitative MRI Measures In The Spinal Cord In MS Patients (The 27th Annual Meeting of the CMSC and the 5th Cooperative Meeting of the CMSC-ACTRIMS)

Friday, May 31, 2013: 4:00 PM

Jiwon Oh, MD , Neurology, Johns Hopkins University, Baltimore, MD

Shiv Saidha, MD , Neurology, Johns Hopkins University, Baltimore, MD

Min Chen, BSc , Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD

Seth Smith, PhD , Department of Radiology and Radiological Sciences, Biomedical Engineering, Physics and Astronomy, Institute of Imaging Science, Vanderbilt University, Nashville, TN

Jerry Prince, PhD , Computer Science, Johns Hopkins University, Baltimore, MD

Craig Jones, PhD , F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD

Peter van Zijl, PhD , Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD

Marie Diener-West, PhD , Biostatistics, Johns Hopkins University, Baltimore, MD

Daniel S Reich, MD, PhD , Translational Neuroradiology Unit, National Institute of Neurological Disorders and Stroke, Bethesda, MD

Peter A Calabresi, MD, FAAN , Johns Hopkins University, Baltimore, MD, USA, Baltimore, MD

Background:

Spinal cord (SC) pathology is common in multiple sclerosis (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.

Objectives:

To determine which combination of quantitative MRI measures in the SC is best able to discriminate between MS patients of differing disability levels.

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(λ_⊥/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<0.10) were retained in the model. When MS patients were stratified into low/high lesion count, SC-CSA and MTR (p<0.10) were retained as covariates in low lesion count settings, while only age and FA (p<0.10) were retained in high lesion count settings.

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.

3.1 Relative Clinical Utility Of Quantitative MRI Measures In The Spinal Cord In MS Patients