Air crescent sign
Encyclopedia
In radiology
, the air crescent sign is a finding on chest radiograph and computed tomography
that is crescenteric and radiolucent
, due to a lung
cavity that is filled with air and has a round radiopaque
mass. Classically, it is due to an aspergilloma
, a form of aspergillosis
, that occurs when the fungus Aspergillus
grows in a cavity in the lung.
Radiology
Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...
, the air crescent sign is a finding on chest radiograph and computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
that is crescenteric and radiolucent
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
, due to a lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
cavity that is filled with air and has a round radiopaque
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
mass. Classically, it is due to an aspergilloma
Aspergilloma
An aspergilloma, also known as a mycetoma or fungus ball, is a clump of fungus which exists in a body cavity such as the lung. It is associated with the Aspergillus species, but Zygomycota and Fusarium may also form similar structures....
, a form of aspergillosis
Aspergillosis
Aspergillosis is the name given to a wide variety of diseases caused by fungi of the genus Aspergillus. The most common forms are allergic bronchopulmonary aspergillosis, pulmonary aspergilloma and invasive aspergillosis. Most humans inhale Aspergillus spores every day...
, that occurs when the fungus Aspergillus
Aspergillus
Aspergillus is a genus consisting of several hundred mold species found in various climates worldwide. Aspergillus was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli...
grows in a cavity in the lung.
