正常引流肺静脉解剖变异的多层螺旋CT血管成像研究

目的 探讨正常引流肺静脉的解剖变异率及其变异形式。方法 回顾性分析2013年5月—2014年7月中山大学附属孙逸仙纪念医院220例两侧肺静脉均引流至左心房患者的胸部64层螺旋CT血管成像(MSCTA)资料,对肺静脉进行多平面重建(MPR)、最大强度投影(MIP)及VR重建,观察段以上肺静脉引流区域,以及双侧肺静脉与左心房连接模式。两侧肺静脉分别以上、下肺静脉独立开口于左房,右中叶肺静脉回流至上肺静脉者为正常肺静脉引流模式;一侧单支或多于两支肺静脉引流、跨叶引流者为肺静脉解剖变异。结果 220例正常引流肺静脉中,左右肺静脉总变异发生率22.7%(50/220)。右肺静脉解剖变异38例(17.3%,38/220),共见8种变异模式,分别为:(1)上、下叶肺静脉分别汇入左心房,中叶静脉汇入下叶肺静脉 4例(1.8%,4/220);(2)上、下叶肺静脉分别汇入左心房,上叶后段汇入下叶肺静脉2例(0.9%,2/220);(3)上、中、下叶静脉分别汇入左心房16例(7.3%,16/220);(4)上叶后段、尖前段、下叶肺静脉分别汇入左心房,中叶静脉汇入尖前段肺静脉4例(1.8%,4/220);(5)上叶、下叶背段、下叶基底段肺静脉分别汇入左心房,中叶静脉汇入上叶肺静脉2例(0.9%,2/220);(6)上叶、 中叶内段、中叶外段、下叶肺分别静脉汇入左心房6例(2.7%,6/220);(7)上叶后段、上叶尖前段、中叶、下叶肺静脉分别汇入左心房2例(0.9%,2/220);(8)上叶、中叶、下叶背段、下叶基底段肺静脉分别汇入左心房2例(0.9%,2/220)。左肺静脉变异12例(5.5%,12/220),共见2种变异模式,即上、下叶肺静脉组成共干汇入左心房8例(3.6%,8/220),上叶、舌叶、下叶肺静脉分别汇入左心房4例(1.8%,4/220)。220例患者中,左右肺静脉解剖变异率的差异有统计学意义(χ²＝13.533, P<0.01)。结论 MSCTA上正常引流肺静脉解剖变异常见,右肺静脉解剖变异发生率显著高于左肺静脉,且变异模式多样。

Research of the anatomic variations in normal pulmonary venous drainage population by multi-slice CT angiography

Objective To investigate the anatomical variant rate and models of normal pulmonary venous drainage to the left atrium on multi-slice spiral CT angiography (MSCTA). Methods Thoracic 64 MSCTA of 220 consecutive patients with all pulmonary venous drainage to the left atrium from May 2013 to July 2014 in the Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University were retrospectively analyzed. The radiographic anatomy of pulmonary veins was revealed by using muti-planar reconstruction (MPR), maximum intensity projection (MIP) and volume rendering (VR) image post-processing to identify each segment of pulmonary vein drainage and connection between pulmonary veins and the left atrium. The normal pulmonary vein drainage was defined as the independently opening of upper and inferior pulmonary veins to the left atrium in each side and the right middle lobe vein opening to upper pulmonary vein. Anatomic variations of pulmonary veins were determined as single or more than two ostia opening of pulmonary veins, and pulmonary venous segment passed through another lobe to the left atrium. Results Among 220 cases with normal pulmonary venous drainage, the overall incidence of right and left pulmonary variations was 22.7%(50/220). Eight types of anatomical variations in the right lung were found in 38 (17.3%, 38/220) cases, including: (1)The right upper lobe and lower lobe pulmonary vein independently drained to the left atrium with right middle lobe vein joined to right lower lobe in 4 (1.8%, 4/220) cases. (2)Right upper lobe and lower lobe pulmonary vein independently drained to the left atrium with posterior segmental vein of right upper lobe joined to right lower lobe in 2 (0.9%, 2/220) cases. (3)the right upper lobe, middle and lower lobe pulmonary vein independently drained to the left atrium in 16 (7.3%, 16/220) cases. (4)The right apical-anterior, posterior segment vein and lower lobe vein independently drained to the left atrium in 4 (1.8%, 4/220) cases. (5)The right upper lobe, superior segment of lower lobe and basal segment of lower lobe vein independently drained to the left atrium with right middle lobe vein joined to right upper lobe in 2 (0.9%, 2/220) cases. (6)The right upper lobe, lateral and medial segment of middle lobe, lower lobe pulmonary vein independently drained to the left atrium in 6 (2.7%, 6/220) cases. (7)The right apical-anterior, posterior segment, middle and lower lobe vein independently drained to the left atrium in 2 (0.9%, 2/220) cases. (8)The right upper lobe, middle lobe, superior segment of lower lobe and basal segment of lower lobe vein independently drained to the left atrium in 2(0.9%, 2/220) cases. Two types of anatomical variations were found in the left side in 12 (5.5%, 12/220) cases, including: (1)Lower lobe vein joined upper lobe vein to form a common trunk in 8 (3.6%, 8/220) cases. (2)The upper lobe, lingular segment and lower lobe pulmonary vein independently drained to the left atrium in 4 (1.8%, 4/220) cases. Conclusions As revealed by MSCTA, anatomical variations of pulmonary venous drainage to the left atrium are not uncommon and the variant patterns are variable.