[MR in the characterization of benign ovarian masses].

To investigate the role of MRI in characterizing benign ovarian masses, the MR images of 64 patients affected with benign ovarian masses were retrospectively reviewed. The benign nature of the masses was proven at surgery (42 cases), fine-needle biopsy (10 cases), laparoscopy (6 cases) and follow-up (6 cases). MRI correctly characterized 56 of 64 masses (87.5%). In particular, all the cases of simple serous cyst (9), of hemorrhagic cyst (10), of fibroma (4), of dermoid cyst (18) and of tubo-ovarian abscess (7). MRI misdiagnosed 4 endometrial cysts--2 of them as hemorrhagic cysts and 2 as dermoid cysts-, 1 serous cystoadenoma as cystoadenocarcinoma and 1 suppurative mucinous cystoadenoma as tubo-ovarian abscess. Moreover, 1 angiofibroma and 1 hematosalpynx were misdiagnosed as endometrial cysts. In conclusion, MRI can be considered a second-choice diagnostic tool which can replace CT in the evaluation of the patients in whom US alone fails to yield an unquestionable diagnosis.