Lückenschädel, scalloping of the posterior surface of the petrous pyramids, falx hypoplasia, falx fenestration, and tentorial hypoplasia with wide incisura and tiny posterior fossa are readily identified by computed tomography (CT) in patients with Chiari II malformation. Enlargement of the foramen magnum may be appreciated on axial section CT in some cases. None of these findings is pathognomonic and each may be observed in some patients with other conditions. In the aggregate, however, these findings strongly suggest the presence of Chiari II malformation.

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In patients with Chiari II malformations, the fourth ventricle is usually not visualized or appears small; the third ventricle is relatively small, typically has a large massa intermedia, and only occasionally exhibits parasellar and/or posterior third ventricular diverticula. The lateral ventricles are usually asymmetrically dilated, show medial pointing of the floor of the body near the foramen of Monro, flattening of the superolateral angles, and frequent absence of the septum pellucidum. Prior to and after shunting, the interhemispheric fissure may be either obliterated, or widely open with serrations corresponding to the interdigitated gyri of the cerebral hemispheres. Prominent confluent cisterns at the hind end of the third ventricle in patients with ventricular collapse may represent the CT equivalent of the dilated pericallosal, ambient and retropulvinaric cisterns seen in patients with hydrocephalus and poor ventricular filling at pneumography.

Five hundred celiac angiograms were reviewed to evaluate the frequency of clinically significant variations in the origin of the left gastric artery. In 13 of 500 cases, the left gastric artery arose anomalously most often as a direct branch of the aorta; in 14 of 500 cases, the left gastric artery primarily supplied the liver with only minor contributions to the stomach. An aberrant origin of the left gastric artery necessarily influences the angiographic diagnosis and therapy of gastrointestinal hemorrhage.

Flattening of the epiphysis of the long bones is seen in several bone dysplasias. It is the hallmark of multiple epiphyseal dysplasia and is an important sign in the diagnosis of spondyloepiphyseal dysplasias, diastrophic dysplasia, and pseudoachondroplastic dysplasia. The goal of this study was to determine norms for the height of the distal femoral epiphysis and to apply these standards to patients with bone dysplasias. Ratios of the distal femoral epiphysis height to both the distal femoral metaphysis width and the distal femoral epiphysis width were obtained from 640 radiographs of healthy children of different ages. Application of these standards to 41 patients with the bone dysplasias mentioned above proved useful in ascertaining decreased height of the distal femoral epiphysis. These standards are of particular value in subtle or early cases in which the thinning of the epiphysis may not be apparent upon simple observation. Obtaining three simple measurements from the anteroposterior knee radiographs allows determination of the presence or absence of flattening of the epiphysis.