Q fever pneumonia: appearance on chest radiographs.

PURPOSE: To determine the radiographic features of Q fever pneumonia.

MATERIALS AND METHODS: Chest radiographs in 85 patients admitted to the hospital during a 7-year period with Q fever pneumonia were retrospectively reviewed by two observers.

RESULTS: The most commonly recorded abnormalities were segmental (n = 53 [62%]) and lobar (n = 15 [18%]) areas of opacity. Segmental pneumonia was observed as a unilateral single area of opacity in 38 (72%) patients. It was more frequently located in the upper lobes. The left upper lobe was involved in 31% of patients, the right upper lobe, in 23%; and the right lower lobe, in 27%. Lobar pneumonia was less frequently observed as a single lesion in eight (53%) of 15 patients; It was located in the left upper lobe in 31% and in the right middle lobe in 27% of patients. There was no correlation between the extent of pulmonary involvement and the course of the disease; the outcome was favorable in all patients. Complete resolution of the radiographic findings occurred in a mean of 39 days.

CONCLUSION: The radiographic differentiation of Q fever pneumonia from the other community-acquired pneumonias is not possible. Clinical, serologic, and epidemiologic data provide the best basis for diagnosis.