Bronchial anatomy of left lung: a study of multi-detector row CT

Abstract

Familiarity with prevailing pattern and variations in the bronchial tree is not only essential for the anatomist to explain bronchial variation in bronchial specimens, but also useful for guiding bronchoscopy and instructing pulmonary segmental resection. The purpose of this study was designed to demonstrate various branching patterns of left lung with 3D images, with special attention given to identify the major types at transverse thin-section CT. Two hundred and sixteen patients with routine thorax scans were enrolled. The images of bronchial tree, virtual bronchoscopy were reconstructed using post-processing technique of multi-detector row CT. We attempted to classify the segmental bronchi by interpreting the post-processing images, and identified them in transverse thin-section CT. Our results showed that the segmental bronchial ramifications of the left superior lobe were classified into three types mainly, i.e., common stem of apical and posterior segmental bronchi (64%, 138/216); trifurcation (23%, 50/216); common stem of apical and anterior segmental bronchi (10%, 22/216), and they could be identified at two typical sections of transverse thin-section CT. There were two major types in left basal segmental bronchi, i.e., bifurcation (75%, 163/216), trifurcation (18%, 39/216), and they could also be identified at two typical sections of transverse thin-section CT. In conclusion, our study have offered simplified branching patterns of bronchi and demonstrated various unusual bronchial branching patterns perfectly with 3D images, and have also revealed how to identify the main branching patterns in transverse thin-section CT.

Quick dissection of the segmental bronchi

“…However, supernumerary bronchi or an abnormal bronchus originating from the trachea are rare. A common variant branch, the subsuperior segmental bronchus in the inferior lobe, which branches from the common trunk of the basal segmental bronchi or stem bronchus supplying the basal segments, is found in 20-30% of left lungs and 50-60% of right lungs (Felson, 1973;Naidich et al, 1988;Wu et al, 1999;Ghaye et al, 2001;Zhao et al, 2009).…”

“…Normal variation and congenital anomalies of the bronchial tree have been studied extensively (Naidich et al, 1988;Wu et al, 1999;Ghaye et al, 2001;Yildiz et al, 2006;Zhao et al, 2009), and numerous variations have been observed in the lobar and segmental bronchial trees. However, supernumerary bronchi or an abnormal bronchus originating from the trachea are rare.…”

“…The B I1II bronchus then divides into the apical and posterior segmental bronchi. This branching pattern was found in 64% of individuals (Zhao et al, 2009). In 23% of cases, the left superior division trifurcates into apical (B I), posterior (B II), and anterior (B III) segmental bronchi, and in 10% of individuals, the left superior division bifurcates into posterior (B II) and apicoanterior segmental (B I1III) bronchi (Zhao et al, 2009).…”

“…The posterolateral stem bifurcates into the lateral basal (B IX) and posterior basal (B X) segmental bronchi. Three-dimensional CT observation of the left basal segmental bronchi showed that 75% of individuals show the bifurcation pattern (anteromedial stem and posterolateral stem) and 10% show the trifurcation pattern (anteromedial stem, B IX, and B X) (Zhao et al, 2009).…”

Deposition of Particles

“…Zhao et al (2009) examined the bronchial anatomy of the left lung in patients (132 men, 84 women; mean age 47 year) who underwent conventional thoracic computed tomography scans for various reasons. At the level of the segmental bronchus in the upper and lower lobes, a bifurcation occurred in the majority of patients.…”