Nonneoplastic and noninfectious diseases of the trachea are rare. Clinical presentation is often nonspecific, with patients complaining of cough, dyspnea, wheezing, stridor, or hemoptysis. In these patients, chest radiography is often considered as unremarkable, the trachea being a radiologic blind spot where substantial disease may easily be missed (1). As CT shows better sensitivity than chest X-ray in detecting tracheal abnormalities, CT has became the technique of choice to assess noninvasively the trachea (2). Single breath-hold helical CT of the airways is free of respiratory motion and step discontinuities caused by respiratory misregistration. High quality multiplanar and 3D reconstructions can be created thanks to the ability of reconstructing overlapped thin slices (3). These reconstructions are of particular interest to illustrate tracheal abnormalities because of the near-vertical orientation of the trachea (4). Nonneoplastic tracheal disorders may enlarge or reduce tracheal diameter. The are classified either as focal or as diffuse abnormalities (5). Helical CT with multiplanar and 3D reconstructions are useful to demonstrate the degree of tracheal widening or narrowing, to show the location and longitudinal extent of disorders, to assess the wall of the trachea, and to demonstrate associated extratracheal diseases. In some instances, CT may help to characterize the abnormality.
Our goal is to present examples of the use of helical CT in various nonneoplastic diseases of the trachea. In this pictorial essay, all abnormalities have been confirmed by fiberoptic bronchoscopy.