Correlation of pulmonary artery dimensions between endobronchial ultrasound and CT scan.

Th e dimensions of the pulmonary artery (PA) on CT scan and the ratio of the main PA to ascending aorta (AA) have been shown to correlate with the diagnosis and severity of pulmonary hypertension. 1 Th e mediastinal vessels are easily visualized with convex probe endobronchial ultrasound (EBUS) as the depth of penetration with EBUS is approximately 5 cm; also, the vessels run adjacent to the airway, and there is no interposition of aerated lung between airways and vessels. 2 Whether the measurements of PA dimensions performed by EBUS correlate with CT scan measurements of the PA remains unknown.