Clinical question: Evaluate epidural fluid. Signs and symptoms: Status post AP CSF leak into epidural space causing back pain and headache. Nonenhanced brain MRI:Diffusion weighted images nondiagnostic due to fairly extensive artifact from patient's dental braces.There is evidence of prior suboccipital Chiari decompression.There is also deterioration of images on other MRI sequences secondary to metallic artifact however they remain diagnostic.Examination demonstrates no detectable intracranial abnormality beyond the artifact that obscures the lower aspect of frontal lobes and anterior bilateral temporal lobes.The cerebral cortex, cortical sulci, ventricular system, CSF spaces and alignment into the brain are unremarkable. The signal void of major intracranial arterial branches are identified. There is intensity of intracranial venous sinuses are beginning normal. Calvarium and soft tissues of the scalp are unremarkable.Images through the paranasal sinuses, orbits are nondiagnostic due to extensive artifact.Nonenhanced total spine MRI:Examination demonstrate expected postoperative changes of Chiari decompression with expansion of subarachnoid space. On sagittal images there is pointed tenting deformity of the posterior cerebellum toward the surgical site/dura which may represent a focus of adhesion.The signal intensity and caliber of the cord remains within normal and in particular no evidence of syrinx is detected. There is no evidence of abnormal signal intensity or fluid collection in the epidural space to suggest CSF leak. There is a thin band of T2 hyperintensity under the subcutaneous fat extending from T11 to L5 (sagittal T2 series 1101 image 10 ) which could represent fluid and possibly as result of CSF leak. This finding measures maximum of 3.5-mm in thickness and overall 152-mm in length. No axial images were acquired on this exam.  There is no evidence of a spinal canal or neural foraminal compromise at any level.CSF flow study is deteriorated secondary to metallic hardware artifact from patient's braces. Within this limitation however the study demonstrate normal biphasic flow through the foramen magnum both anterior and posterior to the cord. There is also detectable flow through the fourth ventricle and the aqueduct.
1.Nonenhanced brain MRI images are degraded due to extensive metallic artifact from patient's dental braces. Beyond the artifacts examination demonstrate no evidence of intracranial pathology. Expected postoperative changes of Chiari decompression is noted.2.Total spine MRI demonstrate expected postoperative changes of Chiari decompression as detailed. No detectable CSF leak into the epidural space. A thin band of fluid signal intensity under the subcutaneous fat extending from T11 to L5 and measuring maximum of 3.5-mm in thickness which could represent fluid and CSF leak. No axial images were acquired on this study. Normal signal intensity and caliber of the cord. Normal CSF flow study at the level of foramen magnum.