Spectrum of magnetic resonance imaging findings in ovarian torsion

PURPOSE: Ovarian torsion is the twisting of the ovary on its vascular pedicle resulting in vascular compromise. Diagnosis of ovarian torsion is challenging in patients who have atypical clinical or ultrasound (US) findings. The objective of our study was to demonstrate the magnetic resonance imaging (MRI) features of ovarian torsion to help radiologists make a conclusive diagnosis when the clinical and US findings are unclear. MATERIAL AND METHODS: We retrospectively reviewed the clinical and MRI features in 10 females with surgically proven ovarian torsion, who had inconclusive clinical, US, or computed tomography findings. RESULTS: All patients showed a significantly enlarged ovary with size ranging from 5 to 18 cm. ‘Twisted ovarian pedicle’ sign was seen in seven patients. Eight cases showed areas of haemorrhage within the ovarian stroma. Non-enhancement of ovarian stroma was observed in six patients. Seven patients showed an ipsilateral deviation of the uterus. CONCLUSIONS: MRI features of ovarian torsion include ovarian enlargement, twisted ovarian pedicle, ovarian haemorrhage, abnormal ovarian enhancement, and ipsilateral deviation of the uterus. Awareness of these imaging features will enable the radiologist to recognise ovarian torsion and differentiate it reliably from other benign or malignant ovarian lesions.