Abstract: Objective     To study the anatomy and drainage pattern of pulmonary veins in the lower lobes of both lungs in healthy people by using multi-slice spiral CT (MSCT), and to elucidate its characteristics, so as to provide basis for the anatomical classification of target veins in anatomic segmental pneumonectomy.    Methods    The CT image data of 200 cases with normal lung were collected, and the venous anatomy and drainage pattern were obtained by VR reconstruction. The occurrence rate of venous classification was observed and counted. Combined with the reconstructed 5 mm axial MIP map, three key observation planes were selected to identify the corresponding subtypes.    Results   V6 could be divided into two types according to the number of stems: single trunk (88%), which was the most common type, and double trunk (12%). In addition, there was an independent segment S* between S6 and S10. There were independent segmental bronchi (B) and arteries (A). The bilateral inferior pulmonary basal veins were characterized by radial arrangement. Most of the branches of the medial basal segment vein (V7) were thin in diameter. The branching patterns of anterior basal segment, lateral basal segment and posterior basal segment veins (V8, V9, V10) could be divided into the following four types: V8+V9 / V10 type, V8 / V9+V10 type, V8+V9+V10 / V10 type, and V8+V9 / V9+V10 type, with different proportion in each type.    Conclusions    The anatomical classification and drainage pattern of pulmonary veins can be used as a routine means of anatomical recognition, which provides basis for the fine anatomical evaluation of pulmonary veins before segmentectomy. The data obtained in this study can be used as a supplement to 3D-CT images, which can help to understand the fine anatomy of target veins and bronchi after segmentectomy.

Key words: Lower lobe of both lungs,  ,  , Venous drainage,  ,  , Bronchial tube,  ,  , Multi slice spiral CT, Anatomical segmentectomy