Which imaging modalities are used to diagnose placenta accreta spectrum?

Which imaging modalities are used to diagnose placenta accreta spectrum?

• A. Ultrasound or MRI
• B. CT scan without contrast only
• C. X-ray
• D. PET scan

Answer: (A)

Diagnosing placenta accreta spectrum hinges on imaging that shows how the placenta attaches to and invades the uterine wall. Ultrasound is the first-line modality because it directly visualizes the placenta’s location and its relationship to the myometrium. It can reveal signs of invasion such as placental lacunae, thinning or interruption of the myometrium, loss of the retroplacental clear zone, and increased placental vascularity on Doppler. These findings help identify accreta, increta, or percreta and aid in planning delivery. Magnetic resonance imaging is used as an adjunct when ultrasound findings are inconclusive, or when the placenta is posterior, the patient body habitus makes ultrasound limited, or detailed mapping of invasion is needed for surgical planning. MRI offers superior soft tissue contrast and can more precisely define the depth and extent of placental invasion and whether surrounding structures are involved. CT scan without contrast, X-ray, and PET scan are not used for diagnosing PAS in pregnancy due to radiation exposure and lack of added diagnostic value for placental invasion.

Diagnosing placenta accreta spectrum hinges on imaging that shows how the placenta attaches to and invades the uterine wall. Ultrasound is the first-line modality because it directly visualizes the placenta’s location and its relationship to the myometrium. It can reveal signs of invasion such as placental lacunae, thinning or interruption of the myometrium, loss of the retroplacental clear zone, and increased placental vascularity on Doppler. These findings help identify accreta, increta, or percreta and aid in planning delivery.

Magnetic resonance imaging is used as an adjunct when ultrasound findings are inconclusive, or when the placenta is posterior, the patient body habitus makes ultrasound limited, or detailed mapping of invasion is needed for surgical planning. MRI offers superior soft tissue contrast and can more precisely define the depth and extent of placental invasion and whether surrounding structures are involved.

CT scan without contrast, X-ray, and PET scan are not used for diagnosing PAS in pregnancy due to radiation exposure and lack of added diagnostic value for placental invasion.