MRI of ovarian torsion: Correlation of imaging features with the presence of perifollicular hemorrhage and ovarian viability

Purpose The purpose of our study is to test for: (a) correlation between the presence of a perifollicular T2-hypointense rim on MRI with the presence of perifollicular hemorrhage on histology; and (b) correlation between this finding and diminished ovarian viability after intra-operative detorsion. Methods and materials Our IRB-approved, retrospective study evaluated 780 patients between August 2012 and February 2016 with ovarian torsion as a diagnostic consideration on the emergency department note. Patients were included if they had preoperative MRI and intraoperatively confirmed case of ovarian torsion. MRIs were retrospectively reviewed for presence of perifollicular T2 hypointense rim in the torsed ovary. Two arms of analysis were performed: (a) assessment of perifollicular hemorrhage on histological exam; and (b) assessment of ovarian viability after intra-operative detorsion. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI for predicting ovarian viability in the setting of torsion was performed. κ test assessed level of agreement between readers. Results 24 patients included in one of the two arms; 20 in viability analysis and 12 in perifollicular hemorrhage analysis (8 in both). The presence of T2-hypointense rim on MRI demonstrated 88.9% sensitivity and 66.7% specificity for the diagnosis of perifollicular hemorrhage on histology, and 91.7% sensitivity and 100% specificity for predicting intraoperative viability. Conclusion The presence of a perifollicular T2 hypointense rim on MRI in the setting of ovarian torsion correlates with perifollicular hemorrhage on histopathologic exam, and may also be a useful predictor of ovarian viability in patients presenting with ovarian torsion.