Convex probe endobronchial ultrasound: applications beyond conventional indications

Abstract

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is maturing and gaining acceptance by more and more clinicians for lymph node staging of lung cancer and diagnosis of mediastinal and hilar masses or lymph node enlargement by convex probe endobronchial ultrasound (CP-EBUS). The application of CP-EBUS, however, is not limited to conventional indications. Diagnostically, elastography is a new technology for the differentiation of benign and malignant lymph nodes before aspiration. CP-EBUS can also be used for pulmonary vascular diseases, such as pulmonary embolism (PE) and non-thrombotic endovascular lesions (NELs). Therapeutically, CP-EBUS can be used for cyst drainage and drug injections. CP-EBUS is not limited to observation and aspiration of mediastinal masses and lymph nodes, but is also suitable for exploration of other tissues external to the central airway, which necessitates unprecedented skills for the bronchoscopist.

Keywords: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA); elastography; pulmonary vascular disease; transbronchial needle injection (TBNI).

Figure 1

Screenshot of group 7 lymph node imaging from EBUS elastography using an ultrasound machine (Hi-vision Avius^®; Hitachi Medical Systems, Kashiwa, Japan) and a bronchial endoscopic ultrasound probe (EB-1970UK video bronchoscope; Pentax, Tokyo, Japan). The image displays B-mode scanning (right side) and elastography color dispersion based on tissue elasticity (left side). A large circle (A zone) contains as much of the entire lesion area as possible, and a small circle (B zone) contains a non-diseased area with a variety of mixed colors. The strain ratio (B/A) is displayed at the bottom right corner of the screen.