Overview of Endobronchial Ultrasonography in Chest Medicine

Endobronchial Ultrasonography (EBUS) can be performed using a balloon, where the probe contacts the object through a balloon filled with medium, or alternatively by a direct contact method where the probe makes direct contact with the object. We established that EBUS using 20 MHz probe shows five layers of the cartilaginous portion of the extrapulmonary bronchus and intrapulmonary bronchus, and three layers of the membranous portion. Pulmonary lesions have an echogenic texture and a sharply defined border due to a strong reflective interface between the aerated lung and the lesion. EBUS for peripheral pulmonary lesions has two main impacts in bronchoscopic diagnosis. One impact is to analyze the internal structures of peripheral pulmonary lesions, and another impact is to detect the location of peripheral pulmonary lesions during bronchoscopy. EBUS using a guide sheath (EBUS-GS) provides the pathway to peripheral pulmonary lesions. One advantage of EBUS-GS lies in the repeatability of access to the bronchial lesion for sampling. Another advantage of EBUS-GS lies in its ability to protect against bleeding into proximal bronchus from the biopsy site. The final advantage of EBUS-GS is the ability to obtain short-axis bronchial views of peripheral pulmonary lesions. For the successful EBUS with transbronchial needle aspiration EBUS-TBNA, we clarify some methods of puncturing between cartilage and obtaining adequate specimens.