PT  - JOURNAL ARTICLE
AU  - Alex Rovira
AU  - Juli Alonso
AU  - Gracia Cucurella
AU  - Carlos Nos
AU  - Mar Tintoré
AU  - Salvador Pedraza
AU  - Jordi Rio
AU  - Xavier Montalban
TI  - Evolution of Multiple Sclerosis Lesions on Serial Contrast-Enhanced T1-Weighted and Magnetization-Transfer MR Images
DP  - 1999 Nov 01
TA  - American Journal of Neuroradiology
PG  - 1939--1945
VI  - 20
IP  - 10
4099  - http://www.ajnr.org/content/20/10/1939.short
4100  - http://www.ajnr.org/content/20/10/1939.full
SO  - Am. J. Neuroradiol.1999 Nov 01; 20
AB  - BACKGROUND AND PURPOSE: Magnetization-transfer imaging is a technique that could provide indirect evidence of the characteristics of multiple sclerosis (MS) lesions. The purpose of this work was to study the evolution of MS lesions on T1-weighted MR images over time and to investigate changes in magnetization-transfer ratio (MTR) values of MS lesions with different initial appearances on contrast-enhanced T1-weighted images.METHODS: Eleven patients with relapsing-remitting MS were studied with MR imaging. The MTRs were calculated for 47 lesions that had been classified according to their appearance on contrast-enhanced T1-weighted images. Each patient was examined at four time points over a 1-year period. The MTR changes observed in the selected lesions were compared with their initial T1-weighted appearance.RESULTS: The lowest MTR values were initially found in hypointense nonenhancing lesions and in ring-enhancing lesions, with both types showing a hypointense center. Changes in MTR values were more dynamic and reversible in ring-enhancing than in hypointense nonenhancing plaques. Nodular-enhancing lesions had slightly lower initial MTRs than did isointense nonenhancing lesions.CONCLUSION: The absence or presence of contrast uptake may indicate a different pathologic basis for hypointense MS lesions on T1-weighted MR images. These differences should be kept in mind when considering T1 lesion load as a surrogate marker of disability in MS.