SLIDE TRAY #4

INFLAMMATION

CT: Brain abscess. Non-contrast (left) and post-contrast (right) axial images of the brain. There is a mass in the deep right cerebral hemisphere with surrounding low attenuation edema. There is mass effect on the lateral and third ventricle and right to left shift. Following contrast injection, the mass shows ring enhancement due to breakdown of blood-brain barrier. The ring is thinner on the side of the mass facing the ventricles, which is frequently seen with abscesses.