A 30-year-old woman at 32 weeks gestation presents with painless bright red bleeding. She is hemodynamically stable. Transabdominal ultrasound reveals the placenta is covering the internal os. Which MRI feature would most strongly predict the need for cesarean hysterectomy in this patient if PAS is also suspected?

• A Increased T1 signal in the placenta indicating hemorrhage
• B Loss of decidua basalis on T2 sequence without uterine bulging
• C Focal placental lake formation on T2 in the lower uterine segment
• D Dark intraplacental bands on T2-weighted imaging (T2 dark bands) ✓

Explanation

On MRI, T2-weighted dark intraplacental bands (low-signal bands within the placenta) are the most specific and predictive feature of abnormally invasive placenta (PAS). Additional MRI features include: uterine bulging, heterogeneous signal intensity, obliteration of the uteroplacental interface, and bladder wall invasion. T2 dark bands correspond to fibrin deposits with hemosiderin at areas of deep invasion. Loss of the retroplacental clear zone (decidua basalis) on T2 is consistent with accreta but less specific than dark bands for the depth of invasion predicting hysterectomy.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.