Benign and malignant gynecologic disease: clinical importance of fluid and peritoneal enhancement in the pelvis at MR imaging.

PURPOSE: To correlate magnetic resonance (MR) imaging findings of pelvic fluid, peritoneal enhancement, and peritoneal nodules with the presence of benign or malignant pelvic disease.
MATERIALS AND METHODS: Pelvic MR imaging findings in 87 women (mean age, 46 years) who subsequently underwent surgery were retrospectively reviewed. Phased-array multicoil, axial spin-echo T1-weighted MR images and axial fast spin-echo T2-weighted images were obtained. The largest pelvic fluid pocket was measured on the T2-weighted images in three orthogonal dimensions. Peritoneal enhancement and nodules were evaluated on gadolinium-enhanced MR images in 54 women.
RESULTS: Pelvic fluid was shown in 21 of 25 patients with malignant neoplasms and 48 of 62 patients with benign disorders. Larger fluid pockets were associated with malignancy rather than with benign disorders, but there was substantial overlap. Use of peritoneal enhancement to diagnose peritoneal spread of tumor had a sensitivity, specificity, accuracy, and positive predictive value of 92% (11 of 12), 86% (36 of 42), 87% (47 of 54), and 65% (11 of 17), respectively. Use of peritoneal nodules for peritoneal spread had a higher specificity (90% [38 of 42]) and positive predictive value (69% [nine of 13]), although the sensitivity was lower (75% [nine of 12]).
CONCLUSION: Large peritoneal fluid pockets are moderately predictive of malignancy or peritoneal spread of tumor. Peritoneal enhancement and enhancing peritoneal nodules are more sensitive and more specific.