What arteries are detectable in the precarinal space on contrast-enhanced CT?

Although the precarinal space is critical in the interpretation of computed tomography (CT) of the thorax, vascular structures within the space have not been well documented. The aim of this study was to investigate vascular structures in the precarinal space that are detectable with contrast-enhanced CT scans. Contrast-enhanced CT chest scans from 90 patients aged 17-78 years (41 male, 49 female) were analyzed retrospectively. Twenty-two cadavers aged 54-93 years (13 male, 9 female) were used for gross anatomic study. We found that 9 of 90 cases of the contrast-enhanced CT scans had vessel-like structures detectable in the precarinal space, located primarily anterior to the right main bronchus. Single or double arteries were identified in the precarinal space of 19 cadavers. Thirteen of the 23 arteries observed were the right bronchial artery and 10 were the left bronchial artery. In two cadavers, a single right bronchial artery (2.5 and 4.0 mm in diameter), which could have been detected with contrast-enhanced CT, originated from the aortic arch and the root of the left subclavian artery and coursed in the precarinal space. Based on the variation in the location and size of the bronchial arteries observed in this study, we suggest that vascular structures are detectable in the precarinal space with contrast-enhanced CT, particularly anterior to the right main bronchus.