VALUE OF PHASE-SHIFT GRADIENT-ECHO MR-IMAGING IN THE DIFFERENTIATION OF PELVIC LESIONS WITH HIGH SIGNAL INTENSITY AT T1-WEIGHTED IMAGING

PURPOSE: To assess the value of phase-shift gradient-echo magnetic res onance (MR) imaging with the fast low-angle shot (FLASH) technique in the differentiation of hemorrhagic tumors and teratomas. MATERIALS AND METHODS: T1- and T2-weighted spin-echo imaging and phase-shift MR ima ging were performed in 60 patients. On T1-weighted images, the signal intensity of lesions was compared with that of intraperitoneal fat. Fi ndings at MR imaging were compared with the surgical findings. The dia gnostic performance of each pulse sequence was analyzed with receiver operating characteristic curves. RESULTS: Sixty high-signal-intensity lesions were identified in 45 patients at T1-weighted imaging. Hemorrh agic lesions and teratomas had similar signal intensities on both T1- and T2-weighted images. Lesions were detected more decisively with FLA SH imaging than with T1- and T2-weighted imaging. CONCLUSION: Phase-sh ift gradient-echo imaging is a readily available method for the differ ential diagnosis of lesions with high signal intensity at T1-weighted MR imaging.