正常支气管与并行动脉比率的高分辨螺旋CT测量

Bronchoarterial Ratio in Normal on HRCT

目的 应用高分辨率CT测量正常人肺段支气管与并行动脉的比率。方法 共 10 0例正常成人作为研究对象。分别在上、中和下肺确定 2～ 3cm的范围 ,用层厚 2mm ,螺距 3mm进行高分辨率螺旋CT扫描。在窗位 -6 0 0HU ,窗宽 15 0 0～ 16 0 0HU下 ,测量肺段支气管外径和伴行动脉直径 ,计算其比率。统计分析这些测量值和≥ 1测量值的解剖位置分布。结果 左右肺支气管与并行动脉的比率分别是 0 .75± 0 .15和 0 .72± 0 .14。男为 0 .75± 0 .15 ,女为 0 .70± 0 .12 ,男明显高于女 (P <0 .0 1)。 12 0 0个测量值中有 87.3% (10 36 / 12 0 0 )的 <1,13.7% (16 4/ 12 0 0 )的≥ 1。这 16 4个≥ 1比率值的分布 ,两肺之间无明显差异 ,但均上肺多于下肺 (P <0 .0 1)。结论 大部分正常人的肺支气管直径小于其伴随动脉。上肺叶可能由于相对缺氧 ,支气管直径大于和等于其伴随动脉的情况较中。

Objective To measure normal bronchial to accompaning pulmonary arterial diameter ratios on HRCT. Methods 100 healthy subjects(male 60,female 40)underwent HRCT scanning to 2～3cm regions of upper, middle and lower lungs respectively. All images were photographed at window level of -600HU and window width of 1500～1600HU.Diameters of the segmental bronchi were measured and compared with the diameter of the adjacent pulmonary artery. Results 1200 bronchi in 100 normal subjects were assessed. The mean bronchoarterial ratio of left and right lungs were 0.75±0.15(mean±SD) and 0.72±0.14,respectively. The ratio in male was significantly greater than one in female ( P <0.01). 1036 of 1200(87.3%) was <1 and 164 of 1200(13.7%) was ≥1. Although the distribution of bronchi with diameter greater than the pulmonary artery had not differ significantly between right and left lungs, the locations of upper lobe were in each side more than middle or lower lobes ( P <0.01). Conclusion The mean values of bronchial to pulmonary arterial diameter ratio in most healthy adults was <1. The conditions of bronchi with diameter greater the pulmonary artery had more in upper lobe than middle or lower lobes, which it is presumably related to hypoxic bronchodiliatation and vasoconstriction.