 The cerebellar tonsils are low lying, extending up to approximately 8 mm inferior to the foramen magnum. There is no evidence of intracranial hemorrhage, mass, or acute infarct. The brain parenchyma and pituitary gland appear unremarkable. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are unremarkable.
1. No evidence of acute or subacute infarct.2. Low-lying cerebellar tonsils are compatible with Chiari 1 malformation. 