Female, 18 years old, history of pseudotumor cerebri with LP shunt now with worsening headache. Brain:No evidence of intracranial mass, mass effect or parenchymal edema is seen. No areas of parenchyma signal abnormality are detected including no evidence of restricted diffusion. Ventricles are normal in size and morphology. No intracranial hemorrhage or any abnormal extra-axial fluid collection is detected. Prominence of the optic nerve sheathes and flattening of the globe at the level of the optic nerve heads are findings compatible with pseudotumor cerebri.The cerebellar tonsils are ectopic terminating up to 3 mm below the level of the foramen magnum. Normal biphasic CSF flow is seen both anteriorly and posteriorly through the foramen magnum including around the cerebellar tonsilsSpine:A shunt catheter enters the thecal sac at the L3-4 level from which point it travels superiorly and seems to terminate at approximately the L1 level. No paraspinal or epidural fluid collections are seen. The nerve roots of the cauda equina disperse evenly through the thecal sac.The central canal of the spinal cord is minimally prominent at the C6 and C7 levels where it measures no more than 1 mm in diameter. Elsewhere spinal cord signal and morphology are entirely within normal limits. The conus tip terminates at the L1 level.Spinal alignment is anatomic. A full complement of vertebral bodies is seen with mild transitional morphology of L5. No evidence of marrow replacement or marrow edema is detected. No significant spinal canal or neuroforaminal stenosis is seen. There is a very small small right paracentral disk protrusion at T7-8.The right vertebral artery is noted to be of uniformly small caliber, likely a developmental variation.
1. Ectopic cerebellar tonsils with preservation of CSF space and CSF flow through the foramen magnum.2. Slight prominence of the optic nerve sheaths and flattening of the globe at the level of the optic nerve heads may reflect pseudotumor cerebri. No other significant intracranial findings are noted.3. A shunt catheter enters the thecal sac at the L3-4 level from which point it travels superiorly to terminate at approximately the L1 level. No paraspinal or epidural fluid collections are seen. Adjacent cauda equina nerve roots are unremarkable.4. Very slight prominence of the central canal of the spinal cord is seen at the C6 and C7 levels. The canal measures no more than 1 mm in diameter. This finding is of uncertain significance and can be a normal variation.