INTRAOBSERVER REPRODUCIBILITY IN MEASURING NEW PUTATIVE MR MARKERS OFDEMYELINATION AND AXONAL LOSS IN MULTIPLE-SCLEROSIS - A COMPARISON WITH CONVENTIONAL T2-WEIGHTED IMAGES

New magnetic resonance (MR) measures considered to be putative markers of demyelination and axonal loss were found to be more closely relate d to clinical disability than T2-weighted MR imaging (MRI) findings in patients with multiple sclerosis (MS). In this study, we evaluated th e reproducibility of such measurements in order to assess their reliab ility for longitudinal studies in MS. The intra-observer coefficients of variation for repeated measurements did not significantly differ am ong the MR techniques studied [2.6% for T2-weighted MRI, 4.38% for une nhanced T1-weighted MRI, 3.65% for magnetisation transfer imaging (MTI ) and 2.28% for spinal cord cross-sectional area at C5]. Our findings suggest that non-conventional MR techniques may be reliable outcome me asures for clinical trials in MS.