RT Journal Article SR Electronic T1 Interscanner Variation in Brain MR Lesion Load Measurements in Multiple Sclerosis Using Conventional Spin-Echo, Rapid Relaxation-Enhanced, and Fast-FLAIR Sequences JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 133 OP 137 VO 20 IS 1 A1 Massimo Filippi A1 Maria A. Rocca A1 Claudio Gasperini A1 Maria P. Sormani A1 Stefano Bastianello A1 Mark A. Horsfield A1 Carlo Pozzilli A1 Giancarlo Comi YR 1999 UL http://www.ajnr.org/content/20/1/133.abstract AB BACKGROUND AND PURPOSE: Different MR pulse sequences have been proposed for measuring multiple sclerosis (MS)-related abnormalities. The reproducibility of measured brain MS lesion volumes was compared for MR images performed using different scanners and different pulse sequences.METHODS: Nine patients with relapsing-remitting MS were each imaged on two scanners and, on each occasion, dual-echo conventional spin-echo, dual-echo rapid-acquisition relaxation-enhanced (RARE), and fast fluid-attenuated inversion recovery (fast-FLAIR) images were obtained. The lesion volume present on each image was evaluated three times by a single observer in random order, using a local thresholding technique.RESULTS: The mean lesion volumes present on fast-FLAIR images were significantly higher than those measured on dual-echo conventional spin-echo and RARE images. The mean intraobserver coefficients of variation for the different sequences and scanners ranged from 3.0% to 4.2% (no statistically significant difference). For each of the sequences, the use of different scanners introduced a variability that was higher than the intraobserver variability: the interscanner coefficient of variation was 7.4% for conventional spin-echo, 9.5% for RARE, and 18.5% for fast-FLAIR images.CONCLUSION: Our study confirms that the use of different scanners significantly influences lesion loads measured from MR images of patients with MS and establishes that newer sequences are more susceptible to measurement variability. It also indicates that, if newer sequences are to be used in clinical trials, careful standardization is needed.