SINGLE-DOSE GADOLINIUM WITH MAGNETIZATION-TRANSFER VERSUS TRIPLE-DOSEGADOLINIUM IN THE MR DETECTION OF MULTIPLE-SCLEROSIS LESIONS

PURPOSE: To compare the efficacy of single-dose gadolinium with magnet ization transfer contrast (MTC) with that of triple-dose gadolinium in detecting enhancing multiple sclerosis lesions. METHODS: Twenty-one p atients with multiple sclerosis were examined with MR imaging first wi th 0.1 mmol/kg gadolinium (single dose) and then, after 24 to 72 hours , with 0.3 mmol/kg gadolinium (triple dose). T2-weighted fast spin-ech o and T1-weighted spin-echo MR images with and without MTC were obtain ed before contrast administration followed by either T1-weighted spin- echo images with MTC (single dose) or conventional T1-weighted spin-ec ho images (triple dose), starting 5, 17, and 29 minutes after contrast administration. All images were evaluated in a blinded fashion and sc ored in random order by two readers. Outcome parameters included numbe r of enhancing lesions, number of active MR examinations (those contai ning at least one enhancing lesion), contrast ratio (signal intensity of enhancing lesion divided by signal intensity of normal-appearing wh ite matter), and size of enhancing lesions. RESULTS: Eighty-one percen t more enhancing lesions and 49% more active MR examinations were dete cted when a triple dose of gadolinium was used as compared with a sing le dose. The level of agreement between readers as to the number of en hancing lesions was significantly higher for triple-dose than for sing le-dose gadolinium. With triple-dose gadolinium, contrast ratios and a reas of enhancement increased by 10% and 33%, respectively. Delayed im aging increased the size of the lesion by 11% on single-dose MTC image s and by 18% on triple-dose images. CONCLUSION: Triple-dose gadolinium is more effective (higher sensitivity and interobserver agreement) th an single-dose gadolinium in combination with MTC in detecting enhanci ng multiple sclerosis lesions.