[Gynecologic and obstetric disorders presenting with abdominal pain]

This article briefly reviews the clinical settings and imaging findings of gynecologic/obstetric disorders presenting with abdominal pain. MR imaging is considered to be an excellent modality for the diagnosis of these disorders because of its high sensitivity to blood. Although CT allows images to be obtained within a shorter time than does MR imaging, the possibility of pregnancy should be excluded prior to the examination. Hemorrhagic ovarian cyst exhibits hyperintensity on T1-weighted images or hematocrit effect on CT or MR images. Hemoperitoneum associated with hemorrhagic cyst strongly indicates rupture of the cyst. Rupture of endometrial cysts and dermoid cysts can cause acute chemical peritonitis. In ectopic pregnancy, findings of hematosalpinx associated with strong enhancement of the tubal wall frequently contribute to the diagnosis. Torsion of the adnexa can be diagnosed by the pedicle between the ovary and uterus, and the lack of contrast enhancement. Tuboovarian abscess is recognized as a cystic mass having a thick wall that is strongly enhanced. Among complications of uterine leiomyoma, red degeneration shows characteristic MR findings, hyperintense rim on T1-WI, hypointense rim on T2-WI, and lack of contrast enhancement. Because of the high incidence of OHSS associated with normal pregnancy, CT is contraindicated.