| Coronary heart disease is very common in coronary artery diseases.Conventional selective coronary angiography (SCA) is considered as the "goldstandard" for its diagnosis ability in site , qualitation and degree definitions .Butsince it is an invasive method , the mortality is about 0.15%,the complicationrate is 1.5%, and for its high cost, hardly can it be accepted by patients. Areliable noninvasive examination method for early diagnosis and screen of CADis highly desirable. Multi-slice spiral CT (MSCT) coronary angiography is a noninvasivemethod, with high time resolution, spatial resolution and isotrophy images .Its3D images show a good perspective in the diagnosis of CA , percutaneoustransluminal coronary angioplasty(PTCA), and the following up of coronarystents and bypass graft. It was found that Multi-slice spiral CT coronary angiography was able toshow the stenosis of coronary artery and degree , with clear view of plaque. Ithas a high sensitivity , specificity and negative predictive value to abovemoderate extent stenosis ,which is helpful to patients with normal coronaryartery or unnecessary invasive method. It can satisfy the need for CAD screen,and is valuable in the following up of bypass graft. 38 cases suspected CAD, 6 cases of coronary stent and 3 cases of coronarybypass graft were involved in our research. MSCT coronary angiography andcoronary artery 3D reconstructions were performed. We analyzed the displayability of MSCT to coronary artery and causes of stenosis, The extent ofstenosis , the stent ,the displays of bypass graft were also evaluated.Methods: MSCT coronary angiography and 3D reconstructions wereperformed to 38 cases suspected CAD, then the display of coronary artery ,calcified plaque and stenosis of every vessel segment were evaluated. Amongthem, 12 cases were compared to SCA results which were done within 1 month .To study the sensitivity, specificity, positive and negative predictive value ofMSCT with SCA results as the gold standard. MSCT coronary angiography and3D reconstructions were performed to 6 cases of coronary stent and 3 cases ofcoronary bypass graft. Then the position, morphology and smooth extent wereevaluated.Results (1) There was no significant difference of display to LM andLAD(p=0.0299>0.01) with different heart rate (HR≥70/min and <70/min),there was significant difference to RCA(p<0.01,x2=10.80) and CX(P<0.05,x2=4.656).(2) Among the 300 segments which lumen diameter were longer than2mm in all 38 cases, there were 102 segments with stenosis at different extent.2segments in LM, 32 in LAD, 33 in RCA, 24 in CX, 11 in D1, and the proportionwas 66.7%,35.6%,36.7%,40%,and 36.7% respectively. Among the 102 segments,16 segments were mild lumen diameter stenosis, and the ratio was 15.7%, 31were moderate, 30.4%,48 were severe,47.1%, 7 were totally obstructed, 6.86%.(3) The sensitivity of diagnosis to above moderate extent stenosis was 80.0%,when compared to SCA results in 12 cases. The false negative ratio was 20.0%,specificity was 81.4%, false positive ratio was 18.6%, positive predictive valuewas 70.8%, negative predictive value was 97.2%, accuracy was 81.3%. (4)There were 11 stents in 6 cases. The position and blood flow were showed , andthe vessels were unobstructed. There were 8 bypass graft vessels in 3 cases. Allof them were unobstructed and no stenosis.Conclusion: (1) The images quality of MSCT coronary angiography isaffected by heart rate and rhyme of patients. There was no significant differenceof display to LM and LAD when the heart rate is≥70/min or <70/min. Therewas significant difference to RCA and CX. (2)MSCTA can show the stenosis indifferent extent and the causes of stenosis, such as calcified plaque and softplaque. It also can show the site of stenosis and the relationship to coronaryartery branches. The information of lumens and vessel wall can also be offered.(3)MSCTA has a high negative perspective value , and is perspectived to be anoninvasive method for screening CAD.(4)MSCTA can display and supply usthe information of the stent and bypass graft well , such as position , stenosis ,and blood flow. It could be used as a conventional examination method afteroperations.
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