16 years, Male, status post Chiari decompression 3 months ago. Evaluate CSF flow and syrinx. Brain: There are postoperative changes of suboccipital craniectomy and resection of the posterior arch of C1 for Chiari I decompression. There has been significant improvement in CSF spaces at the foramen magnum when compared to the sagittal counting sequence on prior thoracic MRI which partially imaged the craniocervical junction.CSF flow sequence is technically suboptimal but demonstrates preserved biphasic flow ventrally and dorsally at the foramen magnum.Multiple brain sequences are motion degraded but demonstrate no significant signal abnormality involving the brain parenchyma. No evidence of intracranial mass, mass effect, midline shift, or herniation. Ventricles appear normal in size. No gross evidence of infarct or hemorrhage. Major flow-voids are preserved.Right maxillary sinus mucus retention cysts are incidentally noted.Cervical and Thoracic Spine:There is been marked decrease in size of the previously seen syrinx extending from approximately the C3-C4 to C7 levels. Cervical syrinx which was partially imaged on the prior thoracic study measured approximately 6 mm in the AP dimension in the sagittal plane at the C4-C5 level, and currently measures less than 1 mm in the AP dimension. Syrinx is relatively maximal on the current study at the C6-C7 level where it measures 2.8 x 5.0 mm in the AP and transverse dimensions which is also smaller than priorThe cervical and thoracic vertebral bodies are appropriate in the overall alignment and height. The thoracic spinal cord has normal signal characteristics and overall morphology. At T5-6 there is a small disc bulge present, and at T6-7 there is a small right paramedian disc protrusion present which mildly indents the cord. These findings are not significantly changed, and there is otherwise no significant spinal canal or neural foraminal stenosis.
Expected postsurgical changes of Chiari I decompression with interval expansion of CSF spaces at the foramen magnum and marked decrease in size of cervical syrinx.