Male, 8 years old, status post Chiari decompression, now with central apnea. Expected findings are seen status post suboccipital craniectomy and resection of the posterior arch of C1. The CSF space posteriorly through the foramen magnum is expanded relative to the prior examination. Robust biphasic CSF flow is seen through the anterior aspect of the foramen magnum. Posteriorly, within the expanded CSF space, there is a blush of flow related signal, but no significant CSF flow is seen along the posterior aspect of the spinal cord from the C2 level down.Cytotoxic edema is evident within the cerebellar tonsils compatible with surgical debulking and tonsillopexi. The tonsils appear much less elongated than on the preoperative examination. Apart from this, no additional significant brainstem or cerebellar edema is seen. The known multiloculated spinal cord syrinx is partially visualized. The brain parenchyma otherwise shows normal morphology and signal characteristics. No significant generalized mass effect is seen. No large intracranial hemorrhage is detected. The ventricular system has increased in caliber by several millimeters, both supratentorially and infratentorially. For example, the right temporal horn now measures 10 mm in width, previously 6 mm.
1.Expected findings status post Chiari decompression. The CSF space through the posterior foramen magnum is expanded and there is evidence of mild CSF flow in this area. No flow related signal is seen, however, more inferiorly along the posterior cervical spinal cord.2.Postoperative changes are seen within the cerebellar tonsils compatible with debulking and tonsillopexi. Edema within these operated tissues is within expected postoperative limits. No other significant brain stem or cerebellar edema is noted.3.Since the prior examination, the caliber of the ventricular system has increased by several millimeters. The size of the ventricles, however, probably remains within normal limits.