Imaging appearance of thoracic amyloidosis.

Amyloidosis is a disease caused by the deposition of abnormal proteins within extracellular soft tissues, and affects the respiratory tract in 50% of cases. Pulmonary involvement may be secondary to systemic disease or due to the accumulation of locally produced amyloid, and this differentiation has important prognostic and therapeutic implications. This pictorial essay, using cases of biopsy-proven respiratory tract amyloidosis, aims to depict the spectrum of imaging findings, and those of CT in particular, that can be of use in distinguishing between the 2 typical patterns of the disease.