 Susceptibility artifact from left parietal approach ventriculocisternal catheter limits evaluation of the adjacent parenchyma on the diffusion sequence. There is no evidence of restricted diffusion to suggest acute ischemia. Interval normalization of the T2 hyperintensity previously seen within the left bilateral occipital lobes with suggestion of development of volume loss. There is also small foci of T2 hyperintensity and volume loss involving the bilateral thalami. These changes are compatible with evolution of previously seen ischemic injury.Bilateral transparietal catheters and disconnected left frontal catheter are again seen. Evidence of prior right frontal ventriculostomy also noted. There is mild interval enlargement of the lateral and third ventricles compared to prior MRI dated 12/2/2014 and minimally larger compared to outside CT dated 1/21/2015 with for example the third ventricle measuring 11 mm in diameter, compared to 7 mm on prior CT from 1/21/2015. Colpocephaly and thinning involving of the corpus callosum, particularly involving the mid callosal body again seen. Tiny foci of susceptibility are again noted along the margins of the ventricular system compatible with chronic blood products. Aqueductal stenosis again noted.No abnormal parenchymal or meningeal enhancement is seen. No evidence of abscess or empyema. Small focus of fluid intensity is seen at the right frontal burr hole site. Major flow-voids are demonstrated in the major intracranial vascular structures. There is significant interval improvement opacification of the mastoid air cells and paranasal sinuses compared to prior MR.
1. Susceptibility artifact from left transparietal catheter limits evaluation of the surrounding parenchyma. There is no evidence of acute ischemia in the visualized brain. No findings to suggest abscess or empyema. If there is suspicion for meningitis, consider lumbar puncture for more sensitive evaluation.2. Compared to prior MR from 12/2/2014, evolution of previously seen ischemic injury involving the occipital cortex and bilateral thalami seen.3. There is minimal interval enlargement of the ventricular system compared to most recent outside CT from 1/21/2015 and much more evident enlargement comparing to prior MRI from 12/2/2014. Third ventriculostomy appears grossly patent but better assessed on prior MRI from 12/2/2014 with high resolution 3D T2 and CSF flow sequence