Clinical stages of human brain abscesses on serial CT scans after contrast infusion

Abstract

The authors describe a classification of human brain abscesses into stages of development as demonstrated on computerized tomography (CT) scans. The results of CT staging of 14 human brain abscesses are compared with the previously published findings in an experimental brain abscess model developed by the same authors. The CT criteria for categorizing brain abscesses into cerebritis and capsule stages were based on the pattern of contrast enhancement and the time-density curve of enhancement obtained from sequential CT scans after contrast infusion. Using these CT criteria, it was possible to accurately categorize all 14 brain abscesses into cerebritis and capsule stages. Histological examination of surgical and autopsy specimens provided immediate confirmation of the abscess stage in six patients. Indirect staging, based on surgical findings and/or subsequent autopsy findings, was possible in eight patients. Corticosteroid administration greatly reduced contrast enhancement in the cerebritis stage, but had little effect in the capsule stage. A systematic approach utilizing CT for establishing the diagnosis, staging, and treatment planning of brain abscess is proposed.