Ovarian torsion: CT and MR imaging appearances.

Abstract

To describe the features of twisted ovarian tumors on computed tomographic (CT) scans and magnetic resonance (MR) images. The CT scans, MR images, clinical records, and histopathologic findings in 10 patients with surgical proof of a twisted adnexal tumor were retrospectively evaluated. The most common findings on MR images were nonspecific: deviation of the uterus to the twisted side (n = 9), engorged blood vessels on the twisted side (n = 6), a small amount of ascites (n = 5), and obliteration of fat (n = 4). The following characteristics were seen only in the five patients with hemorrhagic infarction: (a) a protrusion of the lesion on the twisted side to which the uterus was continuous or engorged blood vessels converged (n = 5); (b) thick, straight blood vessels that draped around the lesion (n = 2); (c) distinct hematoma (n = 2); and (d) complete absence of enhancement (n = 3). Three findings (a, b, and d) seem to be diagnostic of the twisted adnexal tumor and may facilitate prompt surgical intervention at examination with MR imaging or CT.