2-year-old female patient with hydrocephalus status post shunt, persistent altered mental status following hypovolemic shock. Evaluate previously seen infarct on CT head. There is diffuse mild cortical restricted diffusion. Furthermore, the cortex appears mildly thickened and demonstrates mild T2 hyperintensity compatible with edema. On FLAIR images, diffuse sulcal hyperintensity is evident.The brain is dysmorphic in morphology with an apparent cleft extending from the vertex of the right parietal lobe into the ventricular system. There is severe thinning and encephalomalacia of the right parietal, temporal, and occipitals lobes. Surrounding and adjacent to the remaining right parietal, occipital, and temporal lobes, there is an intermediate T1 signal and heterogeneous hyperintense T2 signal subdural fluid collection which displaces the thin residual parenchyma medially. There also appears to be a separate, suprimposed collection of slightly different signal quality between the subdural collection and the right parietal parenchyma. The subdural collection contains thin strands of tissue which may represent fibrous material or degenerated parenchyma. Only minimal susceptibility is evident within the collection.The septum pellucidum is absent. The left half of the corpus callosum is present but thinned. The right half of the corpus callosum is deficient. The right thalamus and posterior right deep brain nuclei appear under developed/atrophic. The midbrain tectum is dysmorphic and the cerebral aqueduct is not visualized. The pituitary is unremarkable. The cerebellar tonsils are pointed in appearance and descend below the foramen magnum. The right posterior cerebral artery flow void is diminutive in its course compared to the contralateral side.There are postsurgical findings related to a right frontal approach ventriculostomy catheter which terminates within the midline anterior aspect of the dysmorphic ventricular system. The ventricular size has increased in size compared to the prior head CT with a transfrontal diameter now measuring up to 74 mm, previously 64 mm.The right eye is deviated superiorly and medially. There is scattered paranasal sinus mucosal thickening. The mastoid air cells are partially opacified.
1. Extensive parenchymal deformity and loss of volume particularly affecting the right cerebral hemisphere. Diffuse mild cortical restricted diffusion which correlates with loss of the gray-white differentiation on prior CT and is concerning for a diffuse hypoxic ischemic event.2. The dysmorphic ventricular system has increased in size compared to the prior head CT.3. An extra-axial, predominantly subdural fluid collection is evident distributed along the residual right posterior cerebrum. The nature of this fluid is not entirely clear. There is only minimal susceptibility artifact to suggest blood product, though this is still in the differential. A nonhemorrhagic proteinaceous or debris-filled hygroma can also be considered.4. Diffuse sulcal FLAIR hyperintensity is likely related to slow vascular flow or disruption of the blood brain barrier in the context of diffuse ischemic injury. Infection would be less likely given the uniform and bilateral distribution.