COMPARISON OF T2 LESION VOLUME AND MAGNETIZATION-TRANSFER RATIO HISTOGRAM ANALYSIS AND OF ATROPHY AND MEASURES OF LESION BURDEN IN PATIENTSWITH MULTIPLE-SCLEROSIS

PURPOSE: The purpose of this study was twofold: first, to compare two different measures of lesion burden in patients with multiple sclerosi s (MS), the magnetization transfer ratio (MTR) histogram and T2 lesion volume; and, second, to investigate the relationship between lesion b urden and atrophy in patients with MS, METHODS: Thirty patients with M S were examined with MR imaging, including fast spin-echo T2- and prot on density-weighted sequences as well as magnetization transfer sequen ces. The lesion burden in each subject was quantitated by MTR histogra phic analysis and by a computer-based method for calculating the total volume of lesions on T2-weighted images, Additionally, the CSF volume , the brain parenchymal volume, and the percentage of brain parenchyma l volume were determined in all patients by using this method and were compared with measurements in eight control subjects. RESULTS: Signif icant loss of parenchymal volume was seen in patients with MS as deter mined by increased CSF volume and decreased percentage of brain parenc hymal volume relative to that in age-matched control subjects. An inve rse correlation was observed between the peak height of the MTR histog ram and T2 lesion volume. T2 lesion volume corresponded positively,vit h CSF volume and inversely with percentage of brain parenchymal volume . The peak height of the MTR histogram corresponded positively with pe rcentage of brain parenchymal volume and inversely with CSF volume, CO NCLUSION: MS patients sustain a significant loss of parenchymal volume (atrophy), which corresponds strongly with increasing lesion burden. T2 lesion volume and peak height of the MTR histogram show good correl ation, and the peak height of the MTR histogram shows a superior corre lation with measures of brain atrophy as compared,vith measurements of T2 lesion volume, suggesting that the MTR histogram may be a better i ndicator of global disease burden than is T2 lesion volume.