The Study Of Clinical Application And Imaging Technology Of 64-slice Spiral Ct Angiography On Coronary Artery

Background&Purpose:Coronary artery disease(CAD) seriously harms human health.More than half of coronary artery diseases happen in the no-symptoms patients. Therefore it is extremely important for early diagnosis of CAD.Coronary artery is the unique blood source to heart.And the nosogenesis of CAD is closely related with anatomy of coronary artery.Precise image of coronary artery by the imageology examination is the precondition for early diagnosis and safe therapy of CAD. Selective coronary angiography(SCA) remains the 'gold standard' to diagnosis of CAD so far.It plays a vital role in the assessment of CAD.However,the invasive procedure is costly and dangerous.With the technical development and significantly improved image quality,64-slice spiral computed tomography as a kind of non-invasive technique plays a potential role in the screening of CAD.It not only displays the stenosis,calcification and coronary atherosclerotic score(CAS) but also is a follow-up way for the patients who have the heart interventional therapy or have the bypass operation of coronary artery.The present study was undertaken to explore the clinical application and imaging technology of 64-slice spiral CT angiography on coronary artery and to evaluate the significance of 64-slice spiral CT in the high risk CAD group.Materials and methods:200 cases imaging material of 64-slice spiral CT angiography on coronary artery were retrospectively analysed.In our study,we investigated preliminarily the influential factors of imaging quality and distribution of CAS and stenosis on 6 branches,compared various kinds of reconstructing methods which include volume redering technology(VRT),maximum intensity projection (MIP),curved planar reconstruction(CPR) and multiplanar volume reconstruction (MPR) in the visualization of anatomic structure,atherosclerotic plaque and stenosis degree,and evaluate preliminarily the myocardial bridge in coronary artery with 64-slice spiral CT angiography.The non-parametric test and Pearson Correlation were used for the statistic analysis,p＜0.05 was considered significant.Results:1.Among the 2600 segments of 200 patients,evaluable segments(1 grade and 2 grade) were 2474 which accounted for 95.1%,unevaluable segments accounted for 5%,the difference had statistical significance(P＜0.001).And abnormal heart rate or cardiac rhythm were the main cause,the difference had statistical significance (P＜0.05).2.There was no difference in the visualization of thicker coronary artery with various kinds of postprocessing technology.But the rate of visualization of slender segment was lower,for example ALD3,LCX3,the difference had statistical significance(P＜0.001).3.419 pieces of coronary artery atherosclerotic plaque were found in the 2600 segments of 200 patients.Most of them were calcified plaque(162/419) and blet were found on LAD(177/419).There was the difference in the coronary artery location of blet,calcified plaque and mixed plaque(P＜0.001). There was no difference in the location of fibrous plaque(P＞0.05).The instable plaque accounted for 52.3%.The detection rate of plaques with MPR was the same as CPR. The detection rate of blet,calcified plaques and mixed plaques with MPR(CPR) was higher than MIP,the difference had statistical significance.However,the detection rate of calcified plaque with MIP was higher than other postprocessing technology, the difference had statistical significance(P＜0.001).4.236 stenosises were found on coronary artery,and there were more stenosises on LAD,RCA and LCX.92 light grade stenosises,90 middle grade stenosises and 54 weight grade stenosises were found.More stenosises which were light and middle grade were found on the mesio-LAD and mesio-RCA.The distribution of weight grade stenosises on different branches had no statistical significance(P＞0.05).The detection rate of different stenosises with MPR was the same as CPR.The detection rate of different stenosises with MPR was higher than other postprocessing technology,the difference had statistical significance.5.25 superficial myocardial bridge cases were found in the 200 cases.The detection rate was 12.5%.They were found on the middle segment of arthritis desecending branch(7/25),distal segment of diagnoal branchl and diagnoal branch(6/25 and 4/25).Conclusion:1 The coronary artery images of 64-slice spiral CT can be used to evaluate the most segments of coronary artery.And the rate of visualization of slender segment was lower.Heart rate or rhythm is still a main influential factor of imaging quality.2.64-slice spiral CT angiography is a reliable method to evaluate the different kinds of CAS and different stenosises of coronary artery,which both locate on the mesio-LAD and mesio-RCA.3.The visualization of thicker coronary artery with different postprocessing technology is similar.They can be used to evaluate different plaques and stenosises. The detection rate of calcified plaque with MIP is higher than other postprocessing technology and the detection rate of stenosises with MPR(CPR) is higher than others.4.64-slice spiral CT is a reliable tool to display the coronary artery anatomy and evaluate CAS,stenosises and superficial myocardial bridge in CAD.It plays primary role in the screening of high risk CAD group.