FAST-SPIN-ECHO (FSE) AND GRADIENT-AND-SPIN-ECHO (GRASE) IN FAST MRI OF THE PELVIS

In this prospective study two different T2-weighted fast spin-echo (FS E) sequences and a gradient- and spin-echo (GRASE) sequence were compa red in 20 consecutive patients undergoing clinical pelvic MR examinati ons. A GRASE and two FSE sequences were applied, whereby the FSE seque nces differed from each other by altered echo spacings (15.0 and 22.5 ms) and T2 contrast. Quantitative image analysis included ROI evaluati on of different S/N and C/N values. Visual image analysis was performe d by two independent readers using a standardized score sheet for anat omic and pathologic findings. Overall image quality was significantly better in both FSE sequences. GRASE and FSE22.5 were superior in delin eation of most of anatomic and pathologic structures due to intermedia te to hypointense contrast behavior of pelvic fat compared to FSE15.0 in which fat was bright. Therefore, FSE15.0 was optimal for low intens ity lesions. Short acquisition times of FSE and GRASE sequences allow application of two different techniques - fat hypointense respectively bright - for excellent lesion visualisation. This study demonstrates the usefulness of contrast manipulation in fast T2-weighted MRI techni ques without special techniques, such as fat saturation. (C) 1997 Else vier Science Inc.