Using CT to diagnose nonneoplastic tracheal abnormalities: appearance of the tracheal wall.

Abstract

1315 he CT diagnosis of nonneoplastic tracheal disease is based on the appearance of the tracheal wall on inspiratory scans, changes in the tracheal wall with expiration, and the location and extent of tracheal abnormalities. Recognizing specific tracheal wall abnormalities is of primary importance because specific diseases tend to affect different components. By noting the portion affected and its abnormal characteristics, a diagnosis may often be suggested. In this pictorial essay, alterations in the appearance of the tracheal wall in certain diseases will be emphasized. CT Technique CT performed with thin collimation is preferred for showing abnormalities of the tracheal wall. Helical CT with 3-mm collimation, a pitch of 2:1, and reconstruction at 2-mm intervals adequately shows these abnormalities and allows volumetric imaging [1]. Twoor three-dimensional reconstructions of the trachea showing wall abnormalities, lumenal morphology, and extent of disease may be useful in selected patients. Expiratory or dynamic expiratory scans may be obtained after or during forced exhalation to show tracheomalacia [2]. Individual high-resolution CT scans may also show tracheal wall abnormalities to best advantage.