Dual-source CT Was Used To Study The Ascending Aorta Elasticity And The Correlation Of Coronary Artery Stenosis

Objective:To explore the clinical feasibility of dual-source computed tomography (DSCT) in evaluating and assessing the elasticity of ascending aorta. A retrospective study by heart switch control imaging technology of DSCT of evaluating every elastic index numerical value of ascending aorta, and to research the relationship with the degree of coronary artery stenosis, and other clinical factors that can influent the elasticity.Method:In this research, there are 118 research objects, among them, masculinity 77 cases, and femininity 41 cases, ages range from 25 to 80, average age 57.45±10.72. Dividing these cases into group with coronary artery stenosis(n=56) and group without coronary artery stenosis (normal group, n=62). In first group, according to the degree of coronary artery stenosis, dividing it into Group mild stenosis (n=33) and Group moderate to severe stenosis (n=24); criteria:on DSCT, diameter of coronary artery< 50%, mild stenosis; 50%～75%,moderate 50%～75% and 76%～100%, severe stenosis, the two laters totally called moderate to severe stenosis. According to the degree of blood pressure, dividing research objects into Group hypertension (n=47) and Group non hypertension (n=71); according to smoking or not, dividing into Group smoking (n=46) and Group non smoking (n=72). Examination apparatus is siemens 64 dual-source CT, with restrospective heart switch control imaging technology to conduct enhanced CT examination of coronary artery, scan area from tracheal subcarinal to diaphragmatic dome, thickness 0.75mm, reconstruction interval 0.5mm, tube voltage 120kv, electric current 380-410mAs. Measure the diameter and area of ascending aorta in systole and diastole separately 2.5cm upper the root ascending aorta, obtaining average value of three measurements as the final results. The index of ascending aorta elasticity including relative diameter changing rate (% Ao), expansibility (AoD, mmHg-1), compliance (AoC, mm2/mm Hg) and stiffness. SPSS 17 was used for statistical analysis, and P<0.05 as statistical difference.Results:1,There were significantly statistical difference(p<0.5) between the no coronary artery stenosis group and coronary stenosis group in the changing rate of lumen diameter, dilatability and the stiffness. While there were no statistical significance difference(p>0.5)in the tubewall’sadaptability.2, There were statistical difference (p<0.5)between Mild coronary artery stenosis and Moderate coronary artery stenosis in the changing rate of the ascending aorta diameter and the degree of stiffness. While there were no statistical significance difference(p>0.5) in the tube’s wall adaptability and the degree of adaptability.3, There were statistical difference (p<0.5)between the degree of coronary stenosis and aortic’s elasticity index,including:the changing rate of diameter, swelling, stiffness, adaptability. Respectively:r=-0.198, p=0.032; r=-0.225, p=0.015; r=-0.198, p=0.034; r=0.260, p=0.015.4, There were no statistical significance difference (r=0.123, p=0.191) between the presence or absence of hypertension and coronary artery stenosis. Respectively:the rate of change in diameter:r=-0.074, p=0.431. dilatability::r=-0.046, p=0.624, adaptability: r=-0.043, p=0.653,stiffness:r=0.052, p=0.578.5, The group of the presence or absence of the history of smoking was significantly associated with coronary artery stenosis. (r=0.294, p=0.001) And there was no significant correlation between the index and the ascending aorta elasticity. Respectively:the rate of change in diameter: r=-0.074,p=0.431.dilatability:r=-0.046,p=0.624,adaptability: r=-0.043,p=0.653,stiffness:r=0.099,p=0.294.Conclusion:The application of dual source CT (DSCT) for measuring the elastic function of the ascending aorta in coronary artery enhancement scanning is feasible and has clinical application value. Most of the elastic index (lumen diameter changing rate, swelling and stiffness) has obvious statistical difference between coronary artery stenosis and no coronary artery stenosis group; and has a good correlation between the degree of coronary artery stenosis and the ascending aorta elasticity index. Smoking’s hypertensive effect on coronary artery stenosisis more meaningful, but their effect on the ascending aorta elasticity is not statistically significant.