Imaging findings in intracranial aspergillosis

The authors' purpose was to elucidate the various computed tomographic (CT) and magnetic resonance (MR) imaging findings in intracranial aspergillosis.

Retrospective analysis of cranial imaging findings was performed in eight proved cases of central nervous system aspergillosis. The patients ranged in age from 17 to 75 years. Four patients were immunocompromised, and four were immunocompetent. CT was performed in all eight patients, and MR imaging in five.

Six patients (75%) had multiple lesions seen on the imaging studies, with a total of 27 focal brain lesions demonstrated. The lesions were most commonly seen in the cerebral hemispheres (n = 21), with lesser involvement of the basal ganglia (n = 2) and the posterior fossa (n = 4). Seven lesions were hemorrhagic on CT and/or MR images. There was a correlation between lesion size and hemorrhage, with hemorrhage more likely in larger lesions (>15 mm). At pathologic examination, foci of hemorrhage were noted within both infarcts and abscesses. Enhancement was noted in five lesions, four of which were confirmed abscesses. Contrast enhancement of the lesions was vague and week in immunocompromised patients but solid and strong in immunocompetent patients. There were 18 lesions without hemorrhage or enhancement; they were either infarcts or abscesses at pathologic examination. Some of these small nonhemorrhagic nonenhancing brain lesions in the subcortical white matter mimicked lacunar infarcts.

Typical imaging findings of intracranial aspergillosis include multifocal lesions involving the cerebral hemispheres, with hemorrhage in approximately 25% of lesions. Lesional contrast enhancement tends to be stronger in immunocompetent hosts.