Diagnostic pulmonary imaging.

This article examines four common but often confusing radiologic problems: the normal thoracic radiograph (performed when clinical suspicion of pulmonary disease is high), the solitary thoracic mass, loss of organ margination, and the mixed pulmonary pattern. Through the use of case examples, a systematic approach to each of the four problems is taken. Contrast and positional radiography, scintigraphy, ultrasonography, and computed tomography are discussed to demonstrate their applications in pulmonary imaging. A brief review of image formation and interpretation of alternate techniques will be provided. The discussion identifies some of the limitations of the radiographic examination, shows why they exist, and illustrates ways of overcoming them.