77-year-old male with abnormal prior MRI, preoperative planning for biopsy. Redemonstrated are postoperative findings in the left occipital scalp including craniectomy. The previously demonstrated associated fluid collection is much smaller. There remains diffuse patchy enhancement within the adjacent parenchyma along the margins of the defect and discrete subcentimeter nodules inferior to the defect. There remains diffusely enhancing tissue between the scalp flap and underlying dura, especially posteriorly. Previously demonstrated patchy bone marrow enhancement along the margins of the craniotomy and the underlying dura is more difficult to assess given the lack of fat saturation with Stealth technique. Enhancement of the left cerebellar hemisphere, with scattered areas of high T2 signal and restricted diffusion are again noted. The degree of mass effect and fourth ventricular effacement has decreased. Cystic appearing components within both the left occipital and left cerebellar enhancement have decreased over the interim. There are also areas of encephalomalacia in the right corona radiata, right basal ganglia, and left thalamus, unchanged. There remains a background of patchy cerebral white matter T2 hyperintensity. The lateral and third ventricles are normal in size, unchanged. There is no midline shift. There is mucosal thickening and retention cyst formation in the left maxillary sinus as well as left mastoid fluid, unchanged.
There remains diffuse patchy enhancement within left occipital parenchyma with discrete subcentimeter nodules inferior to the craniectomy. There remains diffusely enhancing tissue between the scalp flap and underlying dura, especially posteriorly. Enhancement of the left cerebellar hemisphere, with scattered areas of high T2 signal and restricted diffusion are again noted. The degree of mass effect and fourth ventricular effacement has decreased. Cystic appearing components within both the left occipital and left cerebellar enhancement have decreased over the interim.