Peripheral hypervascularity of the corpus luteum with ovarian edema (CLOE) may decrease false positive diagnoses of ovarian torsion.

In patients with pelvic pain, corpus luteum with associated ovarian edema (CLOE) may be mistaken for ovarian torsion on ultrasound or CECT.This was a multi-reader, blinded, retrospective review performed at a single academic center from 2012 to 2018. Cases of CLOE that were misdiagnosed as torsion and cases of ovarian torsion without a lead-point mass were analyzed. Evaluated ultrasound features included presence of a corpus luteum, ovarian and corpus luteum volume, Color Doppler vascularity of the corpus luteum rim compared to that of the ovarian stroma, peripheral follicular displacement, twisted vascular pedicle, and free fluid. Evaluated CT features included presence of a corpus luteum, ovarian and corpus luteum volume, corpus luteum rim enhancement, twisted vascular pedicle, and free fluid.39 cases of CLOE and 30 cases of ovarian torsion without lead-point mass were reviewed. A corpus luteum was present in 56.7% of torsed ovaries. In CLOE cases, peripheral hypervascularity of the corpus luteum (manifested as enhancement at CECT or flow signal at Doppler US) was present in 67.7% (21/31) of cases on ultrasound, and in 95.7% (22/23) of cases on CT. No peripheral hypervascularity of the corpus luteum was seen in cases of torsion (p < 0.001). Torsed ovaries were significantly larger than CLOE cases. Other findings were not significantly different between the two groups.Increased blood flow in the periphery of a corpus luteum on color Doppler ultrasound or on CECT is a strong negative predictor for ovarian torsion.