Magnetisation transfer ratio histogram analysis of primary progressive andother multiple sclerosis subgroups

Introduction: Global magnetisation transfer ration (MTR) histogram analysis in the brain offers a method for evaluating pathological change both as a result of lesions and microscopic changes in normal appearing tissues. Methods: 39 controls and 83 MS patients (46 primary progressive, ii benign, 10 relapsing-remitting, 16 secondary progressive) were studied to explore the relationship of six conventional MTR histogram parameters with MS clini cal subgroups and disability. Principal component (PC) analysis, which make s use of all the histogram data, was also used to examine the relationship between the MTR histogram and disability. Results: When primary progressive patients were compared to controls, there were abnormalities of average MTR, and MTR at the 25th, 50th and 75th perc entile. Disabled relapsing onset patients exhibited abnormalities in the sa me four parameters. Benign and nondisabled relapsing onset patients exhibit ed no significant abnormalities. Modest correlations were observed between disability and individual MTR parameters in relapse onset but not primary p rogressive patients-PC analysis revealed stronger and significant associati ons with disability in both subgroups. (r = 0.40 for primary progressive an d r = 0.51 fur relapsing onset). Conclusion: A number of MTR parameters are abnormal in primary progressive MS. MTR abnormalities are seen in disabled patients, whether of relapsing o r primary progressive onset. The improved correlation with disability obtai ned by PC analysis suggests a useful role of this method for following clin ically relevant pathological changes depicted in the MTR histogram. (C) 200 1 Elsevier Science B.V. All rights reserved.