Competence in endosonographic techniques.

Endobronchial ultrasound (EBUS) has revolutionized the field of bronchoscopy because it allows to observe peribronchial structures and distal peripheral lung lesions. The use of EBUS was first described by Hurte and Hanrath in 1992. EBUS technology exists in two forms: radial and convex transducer probes. The radial EBUS probe has a 20-MHZ (12-30 MHz available) rotating transducer that can be inserted together with or without a guide sheath through the working channel (2.0-2.8 mm) of a standard flexible bronchoscope. The transducer rotates and produces a 360-degree circular image around the central position of the probe. There are two types of radial EBUS probes: "peripheral" probes, used to identify parenchymal lung lesions, and "central" probes, with balloon sheaths, used for the assessment of airway walls and peribronchial lymph nodes.