 There is soft tissue crowding at the foramen magnum with inferior extension of cerebellar tonsils up to 7 mm below the foramen magnum. There is partly imaged cervical cord syrinx measuring up to 3 mm AP on series 5 image 28 which extends superiorly to C1 level. There is mild platybasia, and mild draping of the brainstem around dens tip which has minimally migrated upwards. The CSF space around the lower medulla/cervical cord is diminished.There is no acute infarct, mass effect or midline shift. There is encephalomalacia in the right frontal lobe presumably representing site of remote meningioma resection with minimal curvilinear enhancement which likely represents granulation tissue. There is moderate diffuse volume loss. There is moderate T2 signal abnormality in the periventricular and subcortical white matter which is nonspecific but likely chronic small vessel ischemic changes.The calvarial osseous marrow signal is diffusely low on T1 without a focal lesion.
1.Findings consistent with Chiari I malformation with a partly imaged 3 mm syrinx in the cervical cord extending superiorly to C1 level. Dedicated cervical spine MRI is recommended.2.Platybasia with brainstem draping around a slightly upward migrated dens tip with diminished CSF space.3.Diffusely low calvarial osseous marrow signal, nonspecific and may be reactive to anemia or marrow infiltration of any cause. Correlation with nuclear medicine bone scan can be considered as clinically appropriate.4.Sequela of previous right frontal meningioma resection.