CNS NOCARDIA IN AIDS PATIENTS - CT AND MRI WITH PATHOLOGICAL CORRELATION

Objective: Since CNS nocardiosis is an often fatal yet potentially tre atable infection in HIV patients, we sought to identify and characteri ze imaging features that may suggest the diagnosis in the appropriate clinical setting. Materials and Methods: The CT scans (six), MR scans (one), or both (two) were evaluated in nine HIV patients with patholog ically proven CNS Nocardia asteroides. Chest X-ray films were availabl e in seven patients. Findings were correlated with pathologic examinat ion. Results: All nine patients had brain abscesses, and in seven that received intravenous contrast agent, all lesions demonstrated ring en hancement. Five of nine patients had hydrocephalus and four of these h ad clinical evidence of meningitis. Small subependymal nodules were se en in five of nine patients and four of these also had meningitis. Pat hologic examination in three of nine cases demonstrated a dense inflam matory infiltrate lining the ventricles that extended through the epen dymal lining, producing small subependymal abscesses. Six of seven ava ilable chest X-ray films demonstrated infiltrates due to Nocardia. Con clusion: Our radiologic-pathologic correlation indicates that in an HI V-positive patient with enhancing parenchymal lesions, the additional findings of subependymal nodules and/or meningitis may suggest the dia gnosis of nocardiosis. An associated pulmonary infiltrate can provide a clue to the diagnosis and serve as a more accessible site for biopsy or culture.