Endobronchial Ultrasound: Clinical Applications

Ultrasound is an imaging modality that utilizes the mechanical properties of high-frequency sound waves when passing through tissues of different densities to produce images of the interrogated tissue. Ultrasound has long been used to image thoracic structures, and the use of an ultrasound endoscope allowing visualization of structures surrounding the esophagus was first described in 1980 [1]. In the early 1990s, endobronchial ultrasound (EBUS) was introduced, dramatically changing the practice of bronchoscopy [2, 3]. Before the advent of EBUS, the bronchoscopist’s view was limited to those structures visualized within the airways or with fluoroscopy. The bronchoscopist can now visualize the structures surrounding the airway wall using EBUS. This chapter will review the clinical applications of EBUS. A more detailed discussion of the technical aspects of EBUS will be undertaken elsewhere in this text.