RETURN TO ABSTRACT LISTING


Background
Placenta accreta spectrum (PAS) disorders represent a significant challenge in obstetric care, with potentially life-threatening consequences for both the mother and fetus. In the last 50 years, the incidence of PAS has increased nearly 10-fold. Early diagnosis and management are critical for optimal outcomes, as more than 50% of cases require peripartum hysterectomy to prevent life-threating massive obstetric hemorrhage. This exhibit aims to provide a comprehensive overview of the imaging findings associated with PAS, facilitating a multidisciplinary approach to patient care.

Educational Goals / Teaching Points
PAS encompasses a spectrum of abnormalities, including placenta accreta, increta, and percreta, all characterized by an abnormal adherence of the placenta to the uterine wall. Risk factors for PAS include placenta previa, prior cesarean section, and prior PAS disorder. PAS disorders range in severity from superficial adhesion of the placenta to the myometrium to myometrial invasion. Ultrasound is the initial imaging modality employed in evaluation of PAS. Key sonographic findings include loss of the normal hypoechoic retroplacental clear space, disrupted uterine serosa-bladder interface, and turbulent color Doppler flow at the uteroplacental interface. MRI plays a crucial role in further characterization and surgical planning. On MRI, findings such as myometrial thinning, and direct invasion into adjacent organs can be observed, aiding in the determination of PAS severity. Definitive diagnosis of PAS disorders, however, occurs at the time of delivery using a combination of clinical and histopathologic criteria. Recognition of imaging findings is essential, as this guides clinical decision-making, such as the selection of the most appropriate surgical approach. The involvement of a skilled multidisciplinary team, including radiologists, obstetricians, and surgeons, is crucial for optimizing patient outcomes in cases of suspected PAS.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
In this educational exhibit, we will use a checklist approach to discuss the key imaging features of the PAS on ultrasound and MRI. Representative histopathology images will be shared and suggestions for effective reporting and communication will be made. PAS Checklist: placenta location, placental homogeneity, placental thickness, presence of disorganized vasculature, placental bands, placental lakes/lacunae, abnormal uterine bulge, thinning or defect in the utero, placental interface, prior c-section scar dehiscence, and accreta, increta, or percreta. Placenta pecreta: loss clear zone, presence of bridging vessels, bladder wall disruption, and placental invasion of other structures.

Conclusion
This educational exhibit serves as a concise guide, outlining the essential imaging features of the PAS. Early and accurate identification of these findings can significantly impact patient management and contribute to improved maternal and fetal outcomes. Collaboration within a multidisciplinary team is fundamental in the comprehensive care of patients with PAS, highlighting the importance of radiologists' roles in this complex clinical scenario.