Male 31 years old Reason: eval for colloid cyst resection History: eval for colloid cyst resection Motion artifact mildly degrades image quality and interpretation.Redemonstration of a right frontal ventriculostomy catheter with tip projecting midline in the anterior lateral ventricles. There is artifact from a prior left frontal surgical approach.There is persistent ventriculomegaly involving the lateral ventricles which is slightly decreased when compared to the preoperative MR, and there is slight interval decrease in periventricular T2 signal indicating a decrease in transependymal fluid shift. Foci of air within the anterior lateral ventricles seen on prior CT have decreased. Layering T2 hypointensity within the occipital horns has minimal susceptibility artifact compatible with postoperative blood products. Other scattered foci susceptibility are seen along the ventricular margins consistent with blood products.Redemonstration of a round mass in the third ventricle level of the foramen of Monro with low T1 and low T2 signal and only peripheral enhancement on the postcontrast images compatible with a colloid cyst. This measures 13 x 11 mm in the axial plane previously 17 x 16 mm on preoperative MRI.No pathologic extra-axial fluid collection.There is grossly stable cerebellar tonsils positioning, extending 5 mm below the level the foramen magnum, with associated pointing of the tonsils. Partially visualized syringohydromyelia in the cervical spinal cord at the level of C2 measures 9 x 8 mm in greatest axial dimensions and extends 2.5 cm in the craniocaudal dimension. There is crowding of structures at the level of the foramen magnum.The expected intracranial vascular flow voids are present.
1. Persistent residual colloid cyst at the foramen of Monro which measures 13 x 11 mm, decreased from the preoperative MR.2. Persistent dilatation of the lateral ventricles which is perhaps slightly decreased compared to the preoperative MR. The degree of transependymal CSF flow is also slightly decreased.3. Borderline cerebellar tonsillar ectopia with pointed configuration. Focal syringohydromyelia in the high cervical spinal cord is partially visualized. In retrospect this was present on the prior study but was largely obscured by motion artifact. Findings likely represent sequela of acquired Chiari I malformation. Additional spine imaging can be considered as clinically warranted.