Clinical question: Evaluate for flow through the fourth ventricle. Signs and symptoms: Status post Chiari decompression. Nonenhanced brain MRI:Negative diffusion-weighted images.Examination demonstrates expected postoperative changes of Chiari decompression with resultant expansion of subarachnoid space and without evidence of tonsillar herniation or deformity.There is normal anatomical morphology of brain and with normal signal intensity on all MRI sequences. Unremarkable cerebral cortex, cortical sulci, ventricular system, CSF spaces and brain myelination otherwise.CSF flow study demonstrate presence of biphasic flow through the neo-foramen magnum both anteriorly and posteriorly as well as through the fourth ventricle and the aqueduct.Nonenhanced MRI of cervical spine:There is normal anatomical alignment of vertebral coronal however with straightening of cervical lordosis which could be positional.There is normal signal intensity and caliber of the cervical and upper most visualized thoracic cord down to T5 level. No evidence of spinal canal or neural foraminal compromise or stenosis.Revisualization of expected postoperative changes of Chiari decompression as detailed above.No detectable perispinal soft tissue abnormality.
1.Nonenhanced brain MRI demonstrate expected postoperative changes of the artery decompression and unremarkable brain MRI otherwise.2.Nonenhanced MRI of cervical spine is unremarkable and in particular no evidence of syrinx is detected.3.CSF flow study demonstrates presence of biphasic flow through the neo-foramen magnum both anteriorly and posteriorly as well as through the fourth ventricle and the adequate.