ESR Essentials: Gynaecological causes of acute pelvic pain in women: a primer for emergent evaluation-practice recommendations by the European Society of Emergency Radiology.

Acute pelvic pain (APP) is a common presentation in women of all ages and has both gynaecological and non-gynaecological causes. In the emergency department, the suspected differential diagnosis dictates the chosen imaging modality. For premenopausal patients with APP, transabdominal ultrasound (TAUS) and transvaginal ultrasound (TVUS) are first-line investigations with high sensitivity and specificity for ectopic pregnancy, adnexal torsion, and ovarian cysts and their complications. US may also be valuable in pelvic inflammatory disease. When a non-gynaecological cause is suspected, contrast-enhanced CT (± transabdominal US) is indicated and has the advantage of 24/7 availability and lack of operator dependence. CT, however, may reveal an unexpected gynaecological cause of APP. When available, MRI is an excellent second test to improve diagnostic certainty in pregnant women when US is inconclusive-both for gynaecological and non-gynaecological conditions. MRI has a high diagnostic accuracy for pelvic inflammatory disease and tubo-ovarian abscesses. This article will enable readers to refresh their knowledge of common causes of APP and understand the histopathological processes involved in gynaecological causes of APP and how the imaging findings correlate. It will outline why different modalities are useful in different pathologies and help understand the limitations of each modality, including the requirement for operator expertise (US), relative lack of specificity/sensitivity (CT), and limited availability (MRI). This article excludes pregnancy-related causes of APP (apart from ectopic pregnancy) and also excludes non-gynaecological causes of APP. KEY POINTS: In female patients with acute pelvic pain, ultrasound is the best first modality in suspected gynaecological pathology. CT can be used when non-gynaecological causes of pain are suspected and when US is inconclusive. MRI has limited availability in an emergency setting and may be used in pelvic inflammatory disease and in pregnancy when US is inconclusive.