MR outcome parameters in multiple sclerosis: Comparison of surface-based thresholding segmentation and magnetization transfer ratio histographic analysis in relation to disability (a preliminary note)

BACKGROUND AND PURPOSES: MR imaging is now widely used to monitor disease p rogression in patients with multiple sclerosis (MS), The purpose of this st udy was to explore the relationship between disability status and existing and new MR parameters in MS patients. METHODS: Forty-one patients with clinically definitive MS were studied. MR imaging included T2- and T1-weighted imaging as well as gradient-echo imagi ng with and without magnetization transfer contrast. We used surface-based thresholding segmentation techniques to obtain T2 and T1 lesion load, T1/T2 ratio, and several magnetization transfer ratio (MTR) lesion load paramete rs, MTR histographic analysis included measurements of absolute peak height (aHp), relative peak height (rHp), MTR of the peak (MTRp), mean MTR (MTRm) , and MTR25, MTR50, and MTR75, relating to the integrals of the histogram a t 25%, 50%, and 75%, respectively, of the total area under the curve. All M R parameters were correlated with Expanded Disability Status Scale (EDSS) s core, disease duration, and patient's age, RESULTS: Using surface-based thresholding segmentation techniques, we found relatively low correlations with EDSS, T1 lesion load and T1/T2 ratios cor related most strongly, Regarding MTR histographic parameters, EDSS correlat ed best with rHp but only weakly with others. Similar correlations were fou nd with disease duration, but not with age. CONCLUSION: The best MR correlations with disability were several MTR histo graphic parameters. Our findings may favor the use of these MR parameters o ver T2 lesion load to monitor disease progression in patients with MS, find ings that should be explored further in longitudinal studies.