Detection and characterization of the evolution of cerebral abscesses with diffusion-weighted magnetic resonance imaging--two case reports.

A 57-year-old man and a 45-year-old woman presented with cerebral abscesses. Diffusion-weighted magnetic resonance (MR) imaging and conventional MR imaging clearly showed the different stages of the course of the brain abscesses. As the abscess matured, the signal intensity of the center gradually increased to the typical high value with a low apparent diffusion coefficient (ADC) on diffusion-weighted MR imaging, and enhancement of the capsule on T1-weighted MR imaging with gadolinium. Healing of the abscess was revealed by the signal intensity of the center returning to isointense and an increase in ADC to the baseline. Surrounding edema showed an increase in ADC, followed by a return to the baseline. These changes probably reflect the pathological processes occurring in the abscesses.