FIG 1. Transitory ventriculomegaly at 21 weeks’ gestation. At 29 weeks, US revealed linear hyperechogenicities around the frontal horns. MR imaging was performed at 30 weeks.

A, T2-weighted coronal section at the level of the temporal lobes shows bilateral opercular dysplasia, gyration delay (no frontal or temporal sulci), and a polymicrogyric cortical pattern.

B, T1-weighted coronal section at the level of the atria. Hyperintensity along the inferior aspect of the right atrium (arrow) was overlooked on T2-weighted images. The pregnancy was terminated at 30 weeks’ gestation. NFP findings confirmed gyration and parenchymal lesions.

C, Coronal histologic section at the level of the temporal lobes show diffuse polymicrogyria with opercular dysplasia.

D, Macroscopic coronal view shows right occipital cavitation (arrow). Calcifications were present on histologic examination.