Clinical question: Bleed/mass. Signs and symptoms: Headaches, nausea and vomiting. Nonenhanced CT of head:Images through posterior fossa demonstrate ectopia of cerebellar tonsils consistent with Chiari malformation. The inferior pole of cerebellar tonsils are beyond the field of study. There is complete effacement of subarachnoid space at the level of foramina magnum with deformity of cerebellar tonsils. Follow-up with an MRI is recommended.There is no evidence of intracranial hemorrhage, edema, mass-effect, midline shift or hydrocephalus. Cortical sulci and ventricular system remain within normal limits.Calvarium is intact. Visualized paranasal sinuses and mastoid air cells are unremarkable.
1.Chiari malformation with resultant deformity of cerebellar tonsils and total effacement of subarachnoid space at the level of foramen magnum . CT examination of brain is otherwise unremarkable.2.Recommend follow-up with an MRI examination of brain and including CSF flow study at the level of foramen magnum.