Characteristic MR Imaging Findings of the Neonatal Brain in RASopathies

Measurement techniques used in the study. A, Preterm neonate, gestational age 35 weeks 6 days. T1-weighted MR image shows measurement of the vermis height from the culmen to the uvular lobule on the midsagittal image. B and C, Preterm neonate, gestational age 30 weeks 6 days. T2-weighted MR images show the cerebellar diameter measurement at the widest points of the cerebellum on axial and coronal images, respectively. D, Preterm neonate, gestational age 33 weeks 4 days. T1-weighted image shows cranial base angle measurement with the fonticulus frontalis used as the anterior landmark; midsella, as the vertex point; and the distal tip of the ossified clivus, as the terminal point. E, Measurement of the tentorial angle between the Twining line and a line drawn through tentorium cerebelli with tuberculum sella used as the originating point. F, T1-weighted MR image shows measurement of the infratentorial angle, using a line originating from the midsella drawn through the midpoint of the dural reflection of the torcula herophili to the inner cortex, and a line drawn between the midsella and basion.