GRASE (GRADIENT- AND SPIN-ECHO) MR OF THE BRAIN

PURPOSE: To assess the clinical utility of GRASE (gradient-and spin-ec ho) MR imaging of the brain by comparing it with the T2-weighted turbo spin-echo technique. METHODS: Fifty-three consecutive patients referr ed for MR imaging of the brain were studied with TZ-weighted turbo spi n-echo and GRASE techniques, matched for effective echo time (110 mill iseconds), echo train length (eight), and spatial resolution. The exam inations were evaluated independently by two neuroradiologists for les ion detection (high-and low-signal-intensity lesions) and lesion consp icuity, and for susceptibility, motion, and chemical-shift artifacts. RESULTS: The GRASE technique provided greater detection of both high-a nd low-signal-intensity lesions and of low-signal-intensity lesions wi th paramagnetic susceptibility characteristics (ie, calcium and hemorr hage). Chemical-shift artifacts in the frequency-encoding direction we re more prominent with the turbo spin-echo technique, whereas chemical -shift artifacts in the phase-encoding direction were more prominent w ith the GRASE technique. There was no significant difference in the de gree of diamagnetic susceptibility artifacts at the base of the skull, or in motion artifacts. CONCLUSION: T2-weighted GRASE is a fast imagi ng technique with a potential for replacing turbo spin-echo in routine MR imaging of the brain. GRASE maintains the contrast resolution of t urbo spin-echo imaging and is better at depicting lesions with paramag netic susceptibility characteristics.