Cerebral Malformations

Abstract

During the second trimester cerebral malformations may present with morphological features that are different from those that are seen in a more mature brain. Consequently, the chapter focuses on early detection of cerebral malformations. MR- sequences that might be useful for the detection of changes in fetal brain development are described. A schematic approach, including the assessment of lamination of the brain parenchyma, the appearance of deep gray matter structures, the width and shape of the ventricles and outer CSF spaces, the midline structures, and the cerebellum is suggested. Salient features of the second-trimester appearance of lissencephaly/polymicrogyria syndromes, holoprosencephaly (HPE), and commissural agenesis that may be detected early are discussed.