Presentation
History of cardiac arrest.
Patient Data
![](https://prod-images-static.radiopaedia.org/images/12016368/2fb5a7077588fdd742bad2fca3ac9d02c3f5c06f7fe842309bbd59ac3f55e04e_big_gallery.jpeg)
There is complete reversal of gray and white matter densities with the basal ganglia,
thalami and cortex being hypodense compared to the hyperdense white matter. There is also partial effacement of the cortical sulci. Findings are compatible with diffuse cerebral edema secondary to anoxic/ischemic cerebral injury.
Case Discussion
80 year old female status post cardiac arrest. The head CT demonstrates true reversal of the gray and white matter, keeping with hypoxic-ischemic brain injury. In a normal head CT, the gray matter is white and the white matter is grey. Take a second look at the case and appreciate the true reversal sign. Patient died a few days after the CT scan.