Sensitivity and reproducibility of fast-FLAIR, FSE, and TGSE sequences for the MRI assessment of brain lesion load in multiple sclerosis: a preliminary study.

Abstract

Fast fluid-attenuated inversion recovery (fast-FLAIR), fast spin echo (FSE), and turbo-gradient spin echo (TGSE), new pulse sequences for magnetic resonance imaging (MRI), are able to display multiple sclerosis (MS) lesions more conspicuously (fast-FLAIR) and with shorter imaging times (FSE, TGSE) than is conventional spin-echo MRI. In this study, we scanned 7 MS patients, using fast-FLAIR (18 axial brain slices), FSE (27 slices), and TGSE (9 slices) sequences in the same session, to compare the brain MRI lesion loads detected by these different sequences and the intraobserver reproducibility of these measurements. On the subset of slices (n = 9) covered by all three measurements, the mean lesion load was 7.577 mm3 on fast-FLAIR, 5.248 mm3 on FSE, and 3.080 mm3 on TGSE (p = 0.006) sequences. The mean intraobserver coefficients of variation were 2.92% for fast-FLAIR, 2.86% for FSE, and 4.31% for TGSE (not significant). These findings demonstrate that both fast-FLAIR and FSE sequences may be potentially useful for serial MRI studies for monitoring clinical trials, while TGSE might be useful for speeding diagnostic MRI in MS patients. Longitudinal, clinically correlated studies using these new MRI sequences are needed to confirm these preliminary data.