An analysis of anatomical variations of the left pulmonary artery of the interlobar portion for lung resection by three-dimensional CT pulmonary angiography and thin-section images

PURPOSE The purpose of the present study was to analyze the left pulmonary artery (LPA) branching pattern of the interlobar portion using three-dimensional CT pulmonary angiography (3D-CTPA) and thin-section CT images, and to attempt to diagrammatize these patterns. MATERIALS AND METHODS The study included 320 patients suspected of having lung cancer of the left upper/lower lobe who underwent CTPA. The number and origin of the LPA branches of the interlobar portion, A1 + 2c, A6, and lingular artery from pars interlobaris (PI), were identified meticulously using 3D-CTPA and thin-section images. We then diagrammatized the identified LPA branching patterns of the interlobar portion. RESULTS The diagrammatized LPA branching patterns of the interlobar portion were broadly classified into seven types in the order of bifurcation from proximal to distal. Type 1 was the most frequent (120/320, 37.5%). PI originated from the lower portion, that is, from A8 or the common trunk of A8 and A9 in 95 cases (29.7%). We could also precisely diagrammatize the LPA branching patterns of the interlobar portion into 85 types in all 320 patients. CONCLUSION 3D-CTPA and thin-section images provided precise preoperative information regarding the LPA branching patterns of the interlobar portion.