Considerations in diagnosing brain abscess with computerized axial tomography

Four studies with computerized axial tomography (CT scan) were performed in a 20-year-old man in whom multiple brain abscesses developed while hospitalized for complications of regional enteritis. A large frontal lobe abscess appeared as a nonspecific region of decreased density on the initial CT scans. When iodine was used to enhance the diagnostic sensitivity of the CT scan, this areas was identifiable as an abscess. However, a 1-cm lesion in the right parietal area that extended into the choroid plexus was not delineated. Radionuclide scans detected both lesions, but did not allow pathological identification. We conclude that CT scans should be performed with iodine enhancement whenever brain abscesses are suspected, and that some abscesses that are undetected by CT scans even with iodine enhancment may be delineated but not identified by sodium pertechnetate Tc 99m imaging.