Ultrasound (US) is the first line imaging modality in the evaluation of acute pelvic pain in women; however, challenging imaging conditions and complex pathologies may lead to inconclusive results. MRI offers superior soft tissue resolution and a larger FOV compared to US and avoids ionizing radiation compared to CT. MRI is an excellent second line imaging modality, with drawbacks including cost and exam duration.
Educational Goals / Teaching Points
After reviewing this exhibit, learners will understand the complementary role of US and MRI for acute pelvic pain; enumerate key imaging sequences for suspected urgent gynecologic and obstetric conditions; articulate an organized approach to acute pelvic MRI interpretation; and identify “can’t miss” diagnoses in pregnant and nonpregnant women.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Differential diagnoses for acute pelvic pain in women encompasses both pregnancy-related (ectopic pregnancy, subchorionic hemorrhage, placental abruption, retained products of conception, uterine arterovenous malformation) and non-obstetric diagnoses (adnexal torsion, pelvic inflammatory disease, degenerating leiomyoma, hemorrhagic cyst, cystic neoplasm rupture). MRI allows for better anatomic delineation, characterization of fluid complexity, identification of blood products or intralesional fat, and enhancement pattern. In addition, MRI allows for imaging a larger FOV, which improves evaluation when anatomy is obscured on US due to body habitus, large fibroids, and/or bowel gas.
Pelvic MRI is an appropriate advanced imaging option for the evaluation of acute pelvic pain in women with inconclusive sonographic findings. Relatively short duration imaging protocols can facilitate prompt diagnosis and management.