Computed Tomography Characteristics of Ruptured Corpus Luteum: Does Prior Coitus Modify Findings?

Background & Aims: To determine the effect of prior coitus on CT findings of ruptured corpus luteum.Methods: The subjects were female patients complaining of acute lower abdominal pain, who underwent CT examination. Patients meeting the following criteria were diagnosed with ruptured corpus luteum: 1) an adnexal cystic mass with thick wall, 2) high density ascites (≥20 Hounsfield Units [H.U.]), 3) no CT evidence of acute abdominal diseases, 4) no pregnancy, 5) no prior history of chronic lower abdominal pain, and 6) relief of pain within two weeks. These patients were classified into two groups: with and without coitus within three days before the onset. Then, CT findings were evaluated.Results: A total of 18 patients fulfilled the criteria. Patients with prior coitus (n＝9) showed a larger maximum diameter of the adnexal cyst (38.8 vs 23.5 mm, p＝0.005), higher attenuation of ascites (41 vs 25 H.U., p＝0.017), and a larger amount of ascites (pelvis-limited or beyond pelvis) (p＝0.015), compared to the others (n＝9).Conclusions: Prior coitus affected CT findings such as a larger amount of ascites with higher attenuation.