Male, 56 years old, with history of disseminated Nocardia. Multiple small edema-inducing lesions are seen within both cerebral hemispheres. The most conspicuous is a ringlike lesion within the right occipital lobe measuring up to 8 mm in diameter. Additional smaller lesions are seen at the gray-white junction of the left superior frontal gyrus, and within the right periventricular white matter. The lesions in the right occipital lobe and in the right periventricular white matter demonstrate some degree of diffusion restriction.Numerous additional small foci of non-edematous white matter T2 hyperintensity are seen in both cerebral hemispheres but these are nonspecific. There is ill-defined T2 hyperintensity within the dorsal medulla of uncertain etiology. No significant generalized mass effect is detected. No findings to suggest acute intracranial hemorrhage or any abnormal extra-axial fluid collection are seen. The ventricular system remains within normal limits. Patchy opacification of the ethmoid air cells is noted.
Multiple intracranial lesions are identified ranging in size up to 8 mm. These lesions induce mild local edema but no significant generalized mass effect. The examination is limited without postcontrast images, but given the history, these lesions would be compatible with a Nocardia infection of the brain.