A, Axial SS-FSE T2-weighted image of a 23-gestational-week-old fetus in a monochorionic twin pregnancy complicated by co-twin demise. There is a large area of encephalomalacia (arrow) involving the left frontal and parietal lobes.
B, Coronal SS-FSE T2-weighted image demonstrates several infoldings of the developing cortex (arrow) consistent with polymicrogyria. Findings were confirmed by postnatal MR imaging.