Magnetic Resonance Imaging Evaluation of Ectopic Pregnancy: A Value-Added Review

Ectopic pregnancy (EP) is a known cause of maternal mortality and may be misdiagnosed in up to 50% of pregnant female individuals (Ann Emerg Med. 1996;28(1):10-17). Magnetic resonance imaging, with its superior soft tissue resolution, is a valuable alternative diagnostic modality to diagnose EP when transvaginal ultrasound results are inconclusive. Although an extrauterine gestational sac is the most specific finding, there are other key MRI findings that can aid in diagnosing EP. As availability of MRI access in the emergency department setting increases across the nation, its utility in women with a positive pregnancy test has also increased. Specific MRI findings that are diagnostic of EP include absence of intrauterine pregnancy, adnexal mass separate from the ovary, and hemoperitoneum. In addition, intrauterine ectopic locations, especially intramural, cornual, and cervical pregnancies, can be diagnosed with increased accuracy with the help of MRI. Magnetic resonance imaging is also useful in excluding potential mimics of EP, including adnexal cysts, ovarian neoplasms, and fibroids. In summary, providing an accurate diagnosis and determining the precise location of an EP, which is supported by the use of MRI, is imperative for guiding a patient's treatment to prevent a potentially fatal outcome.