The Study On Pulmonary Venous Imaging Anatomy With 64-slice Spiral CT And The Clinical Value

bjective: To document the variations in pulmonary venous drainage to the left atrium, the size and shape of pulmonary venous ostia, the variational regularity during the cardiac cycle, its distance to the first bifurcation, the variational regularity of pulmonary venous trunk as it approachs the left atrium, and the thickness of venous saddle, so as to provide imaging anatomic data of pulmonary vein(PV) on normal in vivo and valuable information on pulmonary venous anatomy for radiofrequency ablation treating atrial fibrillation and thoracic surgery. Methods: The data of one hundred and four patients(67 males and 37 females) without the diseases affecting pulmonary vein, aged 27～86 years(mean age 59.33 years), were collected in this study. After coronary artery were scanned by 64-slice spiral CT, pulmonary venous drainage patterns to the left atrium were analysed in VR and MIP images. The caliber of PV and its distance to the first bifurcation at 75% R-R interval were measured with vessel analysis software,and venous ostial index(VOI) were calculated. Pulmonary venous ostia were observed and the thickness of venous saddle were measured in VIE images. The left atrium volume were measured and the correlation between the caliber,VOI of PV and the left atrium volume were analysed. Twenty patients(11 males and 9 females) with the same standard, aged 40～75 years(mean age 59.75 years), were collected. The axial view images of pulmonary venous ostia were reconstructed in increments of 10% from 5% R-R interval during the cardiac cycle. The caliber and area of pulmonary venous ostia were measured,so as to investigate its variational regularity during the cardiac cycle. The software package (SPSS12.0) was used to perform the statistical analysis. Of the standard four PVs, the caliber and VOI of the right and the left, the superior and the inferior PV, different gender and age groups were compared by ANOVA and t-test of sample mean, as well as the venous saddle of the right and the left and different gender, the distance to the first bifurcation and ostial branches emergence rate. The correlation between the caliber,VOI of PV and the left atrium volume were analysed. Results: Most patients(n=81,77.8%) had four standard PVs. Of the remainder, 10 patients(9.6%) had accessory right pulmonary vein(ARPV), 8 patients(7.7%) had common left trunk pulmonary vein(CLTPV), 3 patients(2.9%) had accessory left pulmonary vein(ALPV), 1 patient (1.0%) had ARPV with CLTPV, and 1 patient (1.0%) had the most superior pulmonary vein(MSPV). Of the standard four PVs, the caliber of superior pulmonary venous ostia were larger than those of inferior pulmonary venous ostia. The right pulmonary venous ostia were larger than the left pulmonary venous ostia(P=0.000). The VOI of the right were larger than those of the left. The VOI between the left superior and inferior PV were similar (P=0.915), and the others were different. The thickness of bilateral veinous saddles were similar (P=0.1). The caliber of PV in men were larger than those in women(P<0.05). The VOI and the thickness of venous saddle between mem and women were similar(P=0.532;P=0.210). The short caliber of the left superior pulmonary venous ostia were different in age groups between 70 or beyond and 50 to 59, as well as the VOI of the right superior pulmonary venous ostia(P=0.026;P=0.044). The other age groups were similar. The caliber of pulmonary venous ostia had some positive relativity with the left atrium volume(P<0.05). The distance to the first bifurcation of every PV varies. They were different between the left and the right,the superior and the inferior PV(P=0.001). The distance from the left superior pulmonary venous ostia to the first bifurcation were significantly different between men and women (P=0.000). The pulmonary venous ostial branches emergence rate of the right inferior PV(74.7%) was the highest and that of the left superior PV(3.2%) was the lowest. The caliber of some left inferior PV(55.6%) gradually decreased and the caliber of the others increased as they entered the left atrium. All of the pulmonary venous shapes gradually became oval. The size of pulmonary venous ostia was variable during the cardiac cycle. The maximal caliber and area were generally at 35%～45% R-R interval and the minimal caliber and area were usually at 75%～5% R-R interval. Conclusion: 64-slice spiral CT angiography of PV can provide overall and accurate information on pulmonary venous anatomy for clinic. The PVs have a great anatomic variations. There is significant variability in pulmonary venous caliber,shape and ostial branches emergence rate, as well as the thickness of venous saddle. The size of pulmonary venous ostia is variable during the cardiac cycle. Particular care must be taken when the left inferior PV is evaluated for its stenosis, as it usually narrows as it enters the left atrium.