Aspergillosis

  • Etiology: Aspergillus infection whose manifestation is dependent on patient’s immune status
  • Allergic Bronchopulmonary Aspergillosis (ABPA)
    — Etiology: hyperimmune status – hypersensitivity reaction associated with asthma
    — Imaging: affects airways, mucoid impaction with central bronchiectasis – “gloved finger”
    — Clinical: uncommon in children
  • Aspergilloma (Fungus ball / mycetoma)
    — Etiology: normal immunity
    — Imaging: affects / infects pre-existing cavity
    — Complications: pulmonary hemorrhage
  • Invasive aspergillosis
    — Etiology: hypoimmune status / immunocompromised
    — Imaging: affects parenchyma – bronchocentric / angiocentric lesion, halo sign – parenchymal density surrounded by irregular ground glass density (hemorrhagic halo), air crescent sign – central necrosis detached from wall
    — Complications: disease in brain, liver, kidneys, spleen

Cases of Allergic Bronchopulmonary Aspergillosis (ABPA)

Cases of Aspergilloma

Cases of Invasive Aspergillosis

CXR and CT of invasive aspergillosis
CXR AP and lateral (above) shows a round opacity on the lateral view posteriorly projecting over a mid-thoracic vertebral body. Axial CT without contrast of the chest shows a cavitary lesion in the superior segment of the right lower lobe that has a halo sign peripherally with the parenchymal density surrounded by an irregular ground glass density and an air crescent sign with an area of central necrosis detached from the wall of the lesion.