Fig 1.

Female fetus at 20 weeks of gestation at risk of JSRD with normal brain in fetal MR imaging and a normal postnatal outcome. A, Prenatal midline sagittal MR image shows a normal fourth ventricle (arrowhead). The midline cerebellum appears intact and the CM is not dilated. B, Prenatal axial MR image through the level of the lower midbrain shows that the AP diameter of the IP fossa (arrowhead) is smaller than that of the midbrain (isthmus) (arrow). C, Prenatal axial MR image at the level of the pons shows a normal-sized fourth ventricle. Midline vermian tissues appear between the 2 cerebellar hemispheres (arrow). It is difficult to identify the normal superior cerebellar peduncles because of their small size and their downward oblique orientation