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Spectrum of Radiologic Findings
for
Pulmonary Aspergillosis
X. Gallardo, E. Castañer, J.M. Mata, F. Novell, M. Andreu
Introduction
• Aspergillosis is a mycotic disease caused usually by
Aspergillus fumigatus.
• Aspergillus is a ubiquitous soil fungi.
• The manifestations of pulmonary aspergillosis are
determined by the number and virulence of the
organisms and the patient’s immune response.
Pulmonary Aspergillosis Categories
Hypersensitivity
Allergic
Bronchopulmonary
Aspergillosis
Normal
Aspergilloma
Immunosuppression
Chronic illness
Corticosteroids
COPD
Neutropenia
Semi-invasive
Aspergillosis
Acute Tracheobronchitis
Bronchiolitis
Bronchopneumonia
Angioinvasive Aspergillosis
Allergic Bronchopulmonary Aspergillosis
• It is found in patients with long-standing bronchial
asthma.
• Is caused by an hypersensitivity reaction.
• The fungi proliferate in the airway lumen. Immune
complexes and inflammatory cells produce bronchial
wall damage and then bronchiectasis and mucous
plugs containing Aspergillus hyphae.
• Clinical symptoms: wheezing, malaise, low-grade fever,
cough, sputum production, and recurrent pneumonia.
Allergic Bronchopulmonary Aspergillosis
a
b
Imaging findings.
a) Bronchiectasis involving predominantly the upper lobes
(arrows).
b) Tubular opacities related to plugging of airways by hyphal
masses with mucoid impaction (arrows). These lesions can
migrate from one region to another.
Allergic Bronchopulmonary Aspergillosis
a
b
Imaging findings.
Same patient CT scan. CT images better demostrate the bronchiectasis
involving the upper right lobe (a) and some months later filled by mucoid
impaction (b).
Allergic Bronchopulmonary Aspergillosis
Imaging findings.
The impacted mucus can has high attenuation or calcification at CT.
In this case there is evidence of air-trapping secondary to bronchial
obstruction (arrows).
Aspergilloma
• Is an Aspergillus infection without tissue invasion.
• Correspond a conglomeration of fungal hyphae admixed
with mucus and cellular debris within a preexistent
pulmonary cavity
• The most common underlying causes are tuberculosis and
sarcoidosis.
• Clinical symptoms: usually asymptomatic, the most
common clinical manifestation is hemoptysis.
Aspergilloma
a
b
c
d
Imaging findings.
Aspergilloma formation. Patient with a tuberculous cavity in the upper left lobe.
a) Initial apparition of lineal opacities in the cavity corresponding to aspergillus
hyphae.
b) Progressive growing of the fungi almost filling the cavity.
c) Oval mass with soft-tissue opacity separated from the wall of the cavity by
an airspace (“air crescent” sign).
d) Finally the mass separated from de cavity walls moves with the changes
position of the patient.
Aspergilloma
Imaging findings.
Chronic lesions and tuberculous cavity in the upper left lobe.
Thickening of the cavity wall or adjacent pleura may be the earliest
radiographic sign in Aspergillomas formation (arrows).
Approximately 10% of mycetomas resolve spontaneously. Reversibility of
the pleural thickening may indicate the resolution of intracavitary fungal
colonization.
Aspergilloma
a
b
Imaging findings.
CT scan of the same patient shows thickening of the
cavity wall and initial formation of an Aspergilloma (b).
Acute Tracheobronchitis
• Is one of the Airway-invasive aspergillosis.
• Is characterized by the presence of Aspergillus
organisms deep within the airway wall.
• It occurs most commonly in neutropenic patients and in
patients with AIDS.
• Clinical symptoms: are those of acute tracheobronchitis
(dry cough, low fever, chest pain).
Acute Tracheobronchitis
a
b
c
Imaging findings.
Usually radiological examinations are normal. Occasionally, tracheal or
bronchial wall thickening may be seen (arrowheads).
Bronchiolitis and Bronchopneumonia
• Is an other of the Airway-invasive aspergillosis.
• It also occurs most commonly in neutropenic patients
and in patients with AIDS.
• In this case the infection affects the small airways.
• Clinical symptoms: are nonspecific. Fever, cough,
sputum production, dispnea.
Bronchiolitis and Bronchopneumonia
Imaging findings.
Centrilobular nodules and branching linear and nodular areas of increased
attenuation (“tree-in-bud” ). The lesions have a patchy distribution.
Bronchopneumonia presents predominantly as peribronchial areas of
consolidation (arrows).
Aspergillus bronchiolitis and bronchopneumonia are indistinguishable from those
caused by other microorganisms.
Semi-invasive Aspergillosis
• Is characterized by the presence of tissue necrosis
and granulomatous inflammation similar to that seen in
reactivation tuberculosis.
• Factors associated with this form of aspergillosis are:
chronic
illness,
diabetes
mellitus,
alcoholism,
corticosteroid therapy, COPD.
• Clinical symptoms: are often insidious and of long
evolution. Chronic cough, sputum production, fever, and
constitutional symptoms. Hemoptysis has been
reported in 15% of patients.
Semi-invasive Aspergillosis
a
b
c
Imaging findings. Unilateral or bilateral segmental areas of consolidation with or without
cavitations, and multiple nodular areas of increased opacity. The findings progress slowly
over months or years.
a) Residual cavity in the URL and acute parenchymal condensation. Lineal opacities inside
the cavity.
b) Worsening of the condensation one month after empiric antibiotic treatment. Now a
nodular opacity in the cavity is seeing. Aspergillus was isolated at sputum.
c) Resolution of the condensation after antifungal treatment, but with an aspergilloma
formation inside the cavity.
Angioinvasive Aspergillosis
• It is found in patients with severe neutropenia (intensive
chemotherapy,
solid
organ
transplantations
and
immunosuppressive regimens for autoimmune diseases).
• Histology: invasion and occlusion of small to medium-sized
pulmonary arteries by fungal hyphae and formation of necrotic
hemorrhagic nodules or hemorrhagic infarcts.
• High mortality rate.
• Clinical symptoms: Are nonspecific. Cough, chest
hemoptysis, dyspnea. The clinical diagnosis is difficult.
pain,
Angioinvasive Aspergillosis
Imaging findings. CT findings consist of nodules surrounded by a halo of groundglass attenuation (“halo sign”) or pleura-based, wedge-shaped areas of
consolidation. These findings correspond to hemorrhagic infarcts.
Lesions may present necroses after initiation of treatment with resolution of the
neutropenia.
Conclusion
Imaging findings in pulmonary aspergillosis may be
nonspecific.
In the appropriate clinical setting, imaging findings
may suggest and even help establish the specific
diagnosis.