Clinical question: Evaluate for structural abnormality, evaluate Chiari. Signs and symptoms: Headache, Chiari malformation on CT measuring 6 to 7 mm. Pre and post enhanced brain MRI:Examination demonstrates 13 mm herniation of cerebellar tonsil through the foramen magnum with flattening deformity of the tonsil consistent with Chiari malformation.Diffusion-weighted images are unremarkable.Examination otherwise demonstrate normal anatomic cord morphology and signal intensity of brain parenchymal on all MRI sequences.The cerebral cortex, cortical sulci, ventricular system, CSF spaces and brain myelination is unremarkable.The signal void of major intracranial arterial branches are identified.The signal intensity of intracranial venous sinuses and their pattern of enhancement is unremarkable.There is a multi branch vascular enhancement in the left posterior frontal lobe highly suggestive of a congenital developmental venous anomaly. This finding is not associated with any susceptibility signal changes to suggest a cavernoma. Unremarkable enhanced images otherwise for any detectable abnormal parenchymal, leptomeningeal, calvarial or orbital enhancement.All paranasal sinuses and bilateral mastoid air cells and middle ear cavities demonstrate normal pneumatization signal pattern. Minute mucosal thickening of bilateral ethmoid sinuses however is noted.Nonenhanced complete spine MRI:Examination of cervical spine demonstrate above described Chiari malformation with flattening deformity of the tonsils. The signal intensity and caliber of cervical cord remains within normal and in particular no evidence of syrinx is detected. There is normal anatomical developmental vertebral column and without evidence of spinal canal or neural foraminal compromise.CSF flow study demonstrate presence of biphasic flow through the foramen of magnum anteriorly. There is significantly diminished flow posteriorly through the foramen magnum and no convincing flow through the fourth ventricle or the aqueduct. MRI of thoracic spine demonstrate normal anatomical development of vertebral column without spinal canal or neural foraminal compromise.There is normal signal intensity and caliber of the thoracic cord and without evidence of syrinx.MRI of the lumbar spine demonstrate normal anatomical developmental vertebral column without spinal canal or neural foraminal compromise. There is normal termination of the cord at lower L1 level. There is normal signal intensity of the cauda equina and in particular without evidence of fatty filum.Incidental note is made of significantly dilated bladder without detectable abnormality of the bladder wall.
1.Pre- and post enhanced demonstrate Chiari malformation with 13 mm herniation of cerebellar tonsils with resultant flattening deformity. A small left frontal lobe developmental venous anomaly is detected and unremarkable exam otherwise. Paranasal sinuses, mastoid air cells and middle ear cavities are well pneumatized.2.Nonenhanced MRI of spine redemonstrate Chiari malformation as detailed above. Unremarkable total spine MRI otherwise as detailed above. CSF flow study demonstrate biphasic flow anteriorly through the foramen magnum and significantly diminished flow posteriorly without detectable flow through the fourth ventricle or the aqueduct.