Adnexal torsion: magnetic resonance findings in the viable adnexa with emphasis on stromal ovarian appearance.

Purpose To evaluate ultrasound (US) and magnetic resonance (MR) findings in the viable twisted adnexa. Materials and Methods Ten patients underwent US and MR studies before surgical detorsion. Corrected cross-sectional area of the ovary was defined as cross-sectional area minus areas of cysts and follicles superior to 1 cm. On T2-weighted images, signal intensity of the stroma was graded as type 1 when it was equal to that of urine and type 2 when it was less than that of urine but markedly more than the contralateral side. Results The tube was twisted in six cases and the ovary in nine cases. All adnexa were viable. The largest ovarian cross-sectional area and the largest corrected ovarian cross-sectional area of the twisted ovary were significantly larger than those of the contralateral ovary (P = 0.043 for US; P = 0.012 and 0.017, respectively, for MR). These ovaries contained types 1 and 2 hyperintensity in six cases and only type 2 hyperintensity in three cases. Tubal thickening was seen on MR in five cases. Conclusion Tubal thickening, enlargement of ovarian stroma as reflected by the corrected cross-sectional area, and hyperintensity of this stroma on T2-weighted images probably related to edema were useful findings in these viable torsions. J. Magn. Reson. Imaging 2004;20:451–462. © 2004 Wiley-Liss, Inc.