Ovarian torsion: sonographic evaluation.

The sonographic and clinical findings of 13 patients with surgically proven ovarian torsion are reported. Sonography demonstrated an abnormal pelvic mass in all patients. The appearance was nonspecific, ranging from solid to cystic, but frequently reflected the commonly associated ovarian pathology present in 69% of patients. The mass was large (mean diameter: 8 cm) and frequently midline (8/13). The clinical findings were variable and nonspecific, leading to a correct preoperative differential diagnosis in only 35% of patients. Preoperative sonography reduced the likelihood of unnecessary appendectomy in patients with ovarian torsion.