Radiographics 2001 Jul-Aug;21(4):825-37
Spectrum of pulmonary aspergillosis: histologic, clinical, and radiologic
findings.
Franquet T, Muller NL, Gimenez A, Guembe P, de La Torre J, Bague S.
Aspergillosis is a serious pathologic condition caused by Aspergillus organisms
and is frequently seen in immunocompromised patients. At computed tomography
(CT), saprophytic aspergillosis (aspergilloma) is characterized by a mass with
soft-tissue attenuation within a lung cavity. The mass is typically separated
from the cavity wall by an airspace ("air crescent" sign) and is often
associated with thickening of the wall and adjacent pleura. CT findings in
allergic bronchopulmonary aspergillosis consist primarily of mucoid impaction
and bronchiectasis involving predominantly the segmental and subsegmental
bronchi of the upper lobes. Aspergillus necrotizing bronchitis may manifest as
an endobronchial mass, obstructive pneumonitis or collapse, or a hilar mass.
Bronchiolitis is characterized by centrilobular nodules and branching linear or
nodular areas of increased attenuation ("tree-in-bud" pattern).
Obstructing bronchopulmonary aspergillosis mimics allergic bronchopulmonary
aspergillosis at CT and manifests as bilateral bronchial and bronchiolar
dilatation, large mucoid impactions, and diffuse lower lobe consolidation caused
by postobstructive atelectasis. Characteristic CT findings in angioinvasive
aspergillosis consist of nodules surrounded by a halo of ground-glass
attenuation ("halo sign") or pleura-based, wedge-shaped areas of
consolidation. Although imaging findings in pulmonary aspergillosis may be
nonspecific, in the appropriate clinical setting, familiarity with the CT
findings may suggest or even help establish the diagnosis.
