IMPROVED CONTRAST OF ENHANCING BRAIN-LESIONS USING CONTRAST-ENHANCED TL-WEIGHTED FAST SPIN-ECHO MR-IMAGING

OBJECTIVE. The purpose of this study was to evaluate the ability of T1 -weighted fast spin-echo MR sequences to provide improved contrast-to- noise ratios for contrast-enhanced lesions during acquisition times sh orter than those used for conventional T1-weighted spin-echo MR sequen ces. SUBJECTS AND METHODS. We compared contrast-to-noise ratios of 32 enhancing brain lesions in 25 patients on T1-weighted spin-echo (546/1 0 [TR/TE]; two excitations; acquisition time, 4 min 12 sec) and on fas t spin-echo (546/10 [TR/effective TE]; echo-train length, 4; echo spac ing, 10 msec; two excitations; acquisition time, 1 min 45 sec) MR imag es obtained at 1.5 T after IV administration of 0.10 mmol/kg gadopente tate dimeglumine. RESULTS. The contrast-enhanced T1-weighted fast spin -echo MR images showed approximately a 12% reduction in the signal-to- noise ratios of the background white matter without an accompanying re duction in the signal-to-noise ratios of the enhancing lesions or CSF when compared with the contrast-enhanced T1-weighted spin-echo MR imag es, The contrast-enhanced T1-weighted fast spin-echo MR images provide d a 23% improvement in the contrast-to-noise ratios of enhancing lesio ns over the contrast-enhanced T1-weighted spin-echo images (p < .001). CONCLUSION. Contrast-enhanced T1-weighted fast spin-echo MR imaging s howed a statistically significant improvement in contrast-to-noise rat ios at much shorter scan times than those used in conventional contras t-enhanced T1-weighted spin-echo MR imaging.