Endobronchial ultrasonography.

Endobronchial ultrasonography (EBUS) allows visualization of the tracheobronchial tree with real-time ultrasound and permits visualization of the internal structure of pulmonary lesions, which may narrow the differential diagnosis. The indications for EBUS are to (1) determine the depth of tumor invasion of tracheobronchial lesions, (2) define positional relationships with the pulmonary artery and veins and hilar structures and determine the extent of tumor invasion, (3) visualize paratracheal and peribronchial lymph nodes and metastatic lesions and enable EBUS-guided transbronchial needle aspiration (TBNA), and (4) localize and diagnose peripheral pulmonary lesions (benign or malignant). New and evolving applications of EBUS will increase the cost-effectiveness of EBUS in the diagnosis and treatment of thoracic diseases.