Ultrasound of the acute female pelvis.

Ultrasound is the most valuable imaging modality in evaluating the premenopausal female presenting with acute pelvic pain. The appropriate interpretation of the ultrasound study requires correlation with the patient's clinical history and laboratory values. This is especially true of the serum beta-hCG, where ultrasound relies on this test to make the diagnosis of ectopic pregnancy. When the serum test for pregnancy is negative and the patient has an adnexal mass this could be secondary to a complicated ovarian cyst (hemorrhage, rupture), ovarian torsion or pelvic inflammatory disease. The ultrasound image can usually make the diagnosis in conjunction with the clinical papameters, however, this is most difficult in patients with ovarian torsion.