Male, 73 years old, history of multiple subdural hematomas status post evacuation complicated by empyema status postevacuation, now presenting with two weeks of lethargy and altered mental status. Findings are demonstrated compatible with prior left parietal craniectomy. The resultant contour abnormality of the scalp and calvarium appear similar to that seen on prior CT.The dura of the left cerebral hemisphere is diffusely thickened and enhancing, but this is improved relative to the prior MRI. No discrete or enhancing extracranial or intracranial fluid collections are seen.The underlying parenchyma the left frontal and parietal lobes is mildly compressed, likely due to a combination of dural thickening and prolapse of the soft tissues at the level of the craniectomy. Mild intravascular sulcal enhancement in this region probably represents slow flow or vascular engorgement due to the regional compression.Patchy T2 hyperintensity within the parenchyma underlying the craniectomy is not significantly changed the prior examination. Previously seen subarachnoid blood product at this location has resolved.Patchy periventricular T2 hyperintensity also remains elsewhere on both sides brain. Evidence of chronic bilateral lacunar infarcts is also seen in the basal ganglia. No restricted diffusion is evident.No definite pathologic enhancement is seen elsewhere in the brain. Areas of apparent enhancement along the medial left temporal lobe, and at the level of the left caudate head, seen only on the 3-D postcontrast sequence, are most likely artifactual, particularly as they are not confirmed on any other sequence.No new intracranial fluid collections are detected. The ventricular size and morphology are stable and within normal limits.
Multiple sequelae of prior surgery are seen including craniectomy and associated skull deformity, diffuse left-sided dural thickening and enhancement, as well as scattered signal abnormality within the parenchyma subjacent to the craniectomy.No definite evidence of any new or significant intracranial or extracranial fluid collections are seen. No parenchymal edema is detected and there is no definite evidence of pathologic parenchymal enhancement.