The purpose of this study was to identify differences in multidetector-row computed tomography (MDCT) findings of adnexal torsion (AT) according to the anatomical subtypes and identify MDCT findings that may predict conservative treatment.

A total of 295 consecutive women with pelvic pain who underwent preoperative MDCT and subsequent surgery less than 24 h after admission were included in this retrospective study. Among them, 116 women (mean age: 33.9 years; range: 3–80 years) with histopathologically confirmed AT after surgery were included in the final analysis.

On histopathological examination, an underlying ovarian mass was found in 98 women (98/116, 84.5%). In the group without ovarian mass (n=18), massive edema (12/18, 66.7% vs. 16/98, 16.3%; P<0.001) was frequently found. However, in the group with ovarian mass (n=98), twisted tube or pedicle (5/18, 27.8% vs. 55/98, 56.1%; P=0.027) and concentric or eccentric wall thickening (5/18, 27.8% vs. 82/98, 83.7%; P<0.001) demonstrated a statistically significant higher incidence. Based on the surgical and pathological results, the 116 women were classified into three subtypes including ovary-tubal (89/116, 77%), ovary only (22/116, 19%) and tubal only subtype (5/116, 4%). In the ovary-tubal subtype, tubal thickening (88/89, 98.9% vs. 11/22, 50.0%; P<0.001), twisted tube or pedicle (57/89, 64.0% vs. 3/22, 13.6%; P<0.001) and remaining tubal enhancement (52/89, 58.4% vs. 7/22, 31.8%; P=0.025) were more frequently observed than in the ovary only subtype. There was no significant difference between the relative frequency of imaging findings in the cystectomy group and adnexectomy group of the ovary-tubal type.

Knowledge of common and characteristic MDCT findings of AT according to the anatomical subtypes is important to make accurate diagnosis and avoid delayed treatment.