[Role of computed tomography in pulmonary aspergillosis. 20 cases]

Aspergilloma is the most common form of pulmonary aspergillosis. The purpose of this work was to compare computed tomographic findings with features observed on standard radiographs.

We retrospectively reviewed 20 cases of pulmonary aspergilloma. These patients (mean age 36 years) were followed after cure of pulmonary tuberculosis and consulted for hemoptysis. All underwent computed tomography (CT) and standard radiographic explorations. Serology was positive for Aspergillus in 16 cases and clinical and radiographic findings led to the diagnosis in the 4 others. Both supine and prone positions were used for thoracic CT. Slice thickness was 5 mm without contrast injection.

In many cases, standard films evidenced the typical mycetoma seen as a rounded mass of soft tissue density filling a portion of a preexisting cavity or as an air crescent sign, but atypical alveolar opacities, aeric images without aspergillosis colonization and parenchymal destruction predominated in certain cases. The CT-scan demonstrated these features even better revealing the typical cavity in 80% of the cases or an air crescent in 20%. Mobility of the fungus ball was demonstrated by comparison of the prone and supine images. The characteristic CT features allowed certain diagnosis of aspergilloma in 6 patients with atypical radiographic or serologic results.

Computed tomography is highly contributive to the diagnosis of pulmonary aspergillosis, particularly in case of small cavities that may be missed on the standard films. Recognition of the mobility of the fungal ball enables differentiation from a tumor or infectious lesion. CT is also helpful for guiding transparietal treatment.

A computed tomography series should be obtained in former tuberculosis patients consulting for hemoptisis.