ARRS 2022 Abstracts

RETURN TO ABSTRACT LISTING


E1879. Placenta Accreta Spectrum: The Good, the Bad, and the Ugly
Authors
  1. Edwina Chang; Santa Clara Valley Medical Center; Stanford University Medical Center
  2. Luyao Shen; Stanford University Medical Center
Background
Placenta accreta spectrum encompasses varying degrees of abnormal placentation attaching to or invading the myometrium and uterine serosa. It is a significant cause of maternal morbidity and mortality and is one of the most common reasons for emergent hysterectomy. Its prevalence has been rapidly increasing in the United States, partly due to the increase in incidence of Cesarean sections and increasing maternal age. At our institution, MRI and ultrasound (US) are simultaneously performed in the evaluation of the placenta in the second and third trimester. This educational exhibit provides the spectrum of normal and abnormal imaging appearances and pathology we have encountered at our institution.

Educational Goals / Teaching Points
This exhibit aims to discuss the MRI and US imaging protocol in evaluation of the placenta. Participants willlearn the normal and abnormal appearance of the placenta in the second and third trimesters of pregnancy, with an emphasis on the placenta accreta spectrum. We present a spectrum of cases with imaging findings and pathology correlation in the placenta accreta spectrum to understand the key imaging findings that should be reported when interpreting MRI and US exams of the placenta.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Imaging protocols include our institution's MRI and US protocols with imaging sequences obtained in the evaluation of the placenta, with additional directed evaluation based on the same day MRI findings. Imaging appearances include: normal imaging appearance of the placenta in the second and the third trimester; placenta previa; marginal cord insertion and vasa previa, including color Doppler evaluation of vessels coursing the cervical os to exclude entities such as maternal marginal vein; and placenta accreta spectrum, including placenta accreta, placenta increta and placenta percreta.

Conclusion
Placenta accreta spectrum is a significant cause of maternal morbidity and mortality - and is one of the most common reasons for emergent hysterectomy. Given the gravity of the pathology, radiologists have an essential role in evaluating cases of suspected placenta accreta spectrum. Therefore, it is important that residents and attending physicians are knowledgeable in the normal and abnormal imaging appearance of the placenta. This educational exhibit aims to demonstrate the technique and spectrum of imaging findings in evaluation of the placenta, as well as to discuss the key imaging findings that should be in the radiologist's report, based on experiences at our institution.