 Postoperative changes are seen from interval suboccipital craniectomy and resection of posterior arch of C1 for decompression of a Chiari I malformation. The previously pointed cerebellar tonsils are no longer visualized, which suggests surgical resection. There is a widely patent neoforamen magnum, filled with CSF. CSF flow imaging was inadvertently not obtained although was included in the prescribed protocol.The cervical spine is in normal alignment, with trace reversal of the normal cervical lordosis. The vertebral body and disk heights are well-maintained. No worrisome focal marrow signal abnormality is appreciated. The spinal cord is of normal caliber and signal.On the previous MR, there was noted to be focal prominence of the CSF space posterior to the left paramedian cerebellum, grossly appearing similar to prior MRI brain from 2013. This is not included within the axial field of view. It does not appear significantly increased in size within comparing across sagittal images, although the posterior margin is now somewhat obscured by susceptibility artifact from the recent surgery.There is no significant disk bulge, herniation, spinal canal or foraminal stenosis within the cervical spine.
1. Expected postoperative changes following decompression of Chiari I malformation, with surgical resection of cerebellar tonsils and widely patent neoforamen magnum. It CSF flow is clinically desired as was originally ordered, patient may return for additional imaging at no additional charge.2. Partial visualization of previously questioned focal prominence of CSF space dorsal to the left paramedian cerebellum. Previous imaging demonstrated scalloping of the inner table the calvarium, favoring a right small retrocerebellar cyst, versus focal prominence of the cistern. Posterior margin evaluation is limited due to susceptibility artifact from the recent surgery.