Q fever pneumonia: CT findings.

PURPOSE: To evaluate the computed tomographic (CT) features of Q fever pneumonia.

MATERIALS AND METHODS: The authors retrospectively reviewed the chest radiographs and CT scans obtained in 12 patients, who were selected on the basis of chest CT availability from a group of patients with a definite diagnosis of acute Q fever infection during an 8.5-year period.

RESULTS: In all cases, CT depicted lesions indicative of airspace involvement, which was expressed as lobar (n = 3), segmental (n = 3), patchy (n = 3), or a combination of these patterns (n = 3). Involvement of more than one lobe was observed in seven (58%) patients. In one patient with multiple patchy areas of consolidation, nodular lesions with a vascular connection and a halo of ground-glass opacity, which were suggestive of an angioinvasive process, were demonstrated. In addition, CT performed in a patient with acute Coxiella burnetii infection who abused alcohol revealed necrotizing pneumonia. Pleural effusions were seen at both CT and radiography in three patients, and mild lymph node enlargement in isolated regions was seen at CT in four patients. Chest radiography was less accurate than CT in the detection of segmental and patchy areas of consolidation.

CONCLUSION: The typical CT findings of Q fever pneumonia consisted mainly of multilobar airspace consolidation. A nodular pattern accompanied by a halo of ground-glass opacification and vessel connection, and necrotizing pneumonia in the setting of impaired immunity were less frequent.