Chiari malformation, headaches. The cerebellar tonsils extend up to approximately 5 mm inferior to the foramen magnum and display rounded morphologies. In addition, there is intact biphasic flow across the foramen magnum, both anteriorly and posteriorly. There is no evidence of intracranial hemorrhage, mass, or acute infarct. The brain parenchyma appears unremarkable. The pituitary gland is unchanged, measuring up to 10 mm in height, which is within normal limits. There is no abnormal intracranial enhancement. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift. The major cerebral flow voids are intact. The orbits, skull, and scalp soft tissues are grossly unremarkable. There is minimal scattered paranasal sinus mucosal thickening.
The cerebellar tonsils extend up to approximately 5 mm inferior to the foramen magnum and display rounded morphologies. In addition, there is intact biphasic flow across the foramen magnum, both anteriorly and posteriorly.