Evaluation of Posterior Fossa Biometric Measurements on Fetal MRI in the Evaluation of Dandy-Walker Continuum

Examples from cohort of Dandy-Walker continuum with TVAs. Sagittal (A) and axial (D) T2 single-shot FSE images from fetal MR imaging at 30 weeks’ GA demonstrate a BP with elevated TVA at 24°; however, the vermis is normal in size and morphology. Sagittal (B) and axial (E) T2 single-shot FSE images from fetal MR imaging at 32 weeks’ GA with VH. There is a coexisting BP marked by an elevated TVA; however, the tentorium is not considered elevated. Sagittal (C) and axial (F) T2 single-shot FSE images from fetal MR imaging at 24 weeks’ GA with classic DWM. The vermis is very small and rotated, and the tentorium is elevated with upward displacement. There is also separation and flattening of the cerebellar hemispheres (F, arrows).