CT findings in immunocompromised patients with pulmonary infections.

PURPOSE: To evaluate computed tomography (CT) findings of pulmonary infections in immunocompromised patients with hematologic malignancies, and to detect the accuracy of first-choice diagnoses.

MATERIALS AND METHODS: CT chest scans of 57 immunocompromised patients who had pulmonary infections were evaluated retrospectively, and a first and second interpretation of etiology (first- and second-choice diagnosis) was proposed. The etiology of pulmonary infection was verified by microbiological tests such as blood, sputum, bronchoalveolar lavage (BAL) cultures, sputum, and BAL smears, or diagnosed on the basis of response to treatment and clinical follow-up.

RESULTS: Nineteen patients had a bacterial infection, 20 patients had a fungal infection, 8 patients had a cytomegalovirus (CMV) infection, 8 patients had Pneumocystis jiroveci pneumonia (PCP) and 2 patients had a Mycobacterium tuberculosis infection. There were consolidations in 13 patients (68.4%) and areas of ground-glass attenuation and ground-glass nodules in 6 patients (31.6%) with bacterial infection. Six of 8 eight patients (75%) with CMV infection had centrilobular nodules associated with bronchial wall thickening and ground-glass areas and nodules. There were parenchymal nodules in 18 of 20 patients (90%) who had a fungal infection. All 8 patients who had PCP had bilateral areas of ground-glass densities on CT scans. The first-choice diagnosis was accurate in most of the fungal infections (95.0%) and PCP (87.5%), but was less accurate for bacterial and viral infections (73.7% and 75.0%, respectively). Neither of the 2 tuberculous infections was identified on the basis of CT findings.

CONCLUSION: In the evaluation of febrile immunocompromised patients, pulmonary fungal infection and PCP may be identified with high accuracy on the basis of CT findings.