Comparative Study Between Dual Source Ct Coronary Angiography And Conventional Coronary Angiography

Comparative study between dual source CT coronary angiography and conventional coronary angiography[Objective]Coronary angiograghy is the standard of reference in the diagnosis of coronary artery disease.But for it is invasive imaging examination , only display aerial image of the arterty and about 1/3 of patients is the normal results,so not all the people subsequently underwent percutaneous transluminal coronary angioplasty. These facts illustrate the need for reliable noninvasive imaging tools in the early and diagnosis of coronary artery disease.with the advent of dual source computed tomography(DSCT) combined with 2 detectors and subsecond rotation(about 83ms),as compared with conventional multi-slice CT,not only is acquisition time markedly decreased,but Z-plane and in-plane resolution are also substantially improved.DSCT have preferable ascendency in the diagnosis of coronary artery disease.We studied retrospectively 84 patients who had undergone DSCT,to evaluate the diagnostic accuracy of dual source CT(DSCT) for the detection of coronary artery stenosis.]Methods]We studied retrospectively 84 patients (58 men and 26 women) who with suspected coronary arterial disease (CAD) were performed coronary artery CT angiography with DSCT (DSCTA) before conventional coronary angiography (CAG) from February 2008 to January 2009. Mean patient age was 65 years (range ,42-78 years). Patients heart rate was 71 beats per minute(bpm)(range ,47-107 bpm).All CT scans were obtained by using dual source computed tomography (SOMATOM Definition,DSCT) from Siemens,Germany.A standard scanning protocol was applied,with 0.6mm section collimation,0.2-0.5 pitch,0.33s rotation time. Each scan was obtained at 120 kV and 380-420mAs. All patients received 80-100 ml of a noniodine contrast medium at a flow rate of 5.0 ml/s. Region of Interest,(ROI) was setted in the ascending aorta,the triggering threshold value was 100HU. Iamge reconstruction was perfomed with 0.75mm effective section thickness,0.5mm increment,and B26f kernel. All reconstruction was performed by using retrospective ECG gating .All data sets were displayed by using four visualizationg techniques: curved planar reconstruction,(CPR),volume rendering technique(VRT),maximum intensity projection (MIP) and ANGIOVIEW,all these were performed at a workstation(Siemens). Evaluation of the coronary arteries was performed according to the classification of the American Heart Association, which differentiates between 15 segments. All statistical using SPSS 13.0 Statistical analysi software.The diagnostic accuracy of DSCTA was evaluated by comparison with CAG, which was regarded as a gold standard for diagnosis.[Results]In all 84 patients, 2 patients coronary artery inborn variation; 2 patients coronary artery fistula; 15 patients clearly displaying myocardial bridge(MB).Two hundred and forty-four segments with stenosis of various degree were found in these 84 patients. Sensitivity,specificity,positive predictive value and negative predictive value of the DSCT in detecting coronary artery stenosis were 97.40%, 97.80%, 92.21% and 100%, respectively.The diagnostic accuracy rate of DSCT in detecting coronary artery stenosis was 96.50%.No significant difference was shown between DSCTA and CAG for the detection of coronary arterial stenosis using a pairedχ2 test.[Conclusion] DSCTA has high accuracy in detecting coronary artery stenosis compared to CAG. It is a useful and non-invasive method for detecting CAD.