Clinical Application Of Low Voltage Examination Of Triple-Rule-out With DSCT In Acute Chest Pain

ObjectiveTo analyze the value of triple-rule-out (TRO) with dual-source computed tomographic angiography in acute chest pain patients with diseases of pulmonary artery, aortic and coronary artery, and compare with quality, noise of pictures and radiation dose in two kinds of tube tension conditions, and assess the feasibility of generalizing and applying in patients with acute chest pain.Method and materials361patients with clinical acute chest pain underwent dual-source CT. All the patients were randomly divided into two groups according to different tube voltages. The voltage120kV group was120kV and current was320mAs. The voltage100kV group was100kV and current was320mAs. In examination, after nonionic contrast-medium Iopromide90ml was injected at the rate of4.5ml/s through the right antecubital vein by double-tube high pressure syringe, physiological saline30ml was injected at the same rate. Region of interest (ROI) was set up in the bifurcation of pulmonary artery. CARE Dose4D and ECG pulsing (35%-75%R-R interval) were used in two groups. All the pictures were transmitted into Siemens Syngo MMWP station and performed with post-processing of CPRs、MIP、MPR and VR, and then the qualities of pictures were subjectively and objectively given marks and radiation dose were statistically analyzed.Result163patients with the stenosis of coronary artery more than≥50%were found among361patients, including severe stenosis and occlusion117cases; Pulmonary embolism39cases (3cases at the level of pulmonary trunk,36cases in pulmonary segments and subsegments), coronary artery with severe stenosis associated with pulmonary embolism1case; Aortic dissecting aneurysm11cases (Debakey I type4cases, Debakey III type7cases). Ascending aortic aneurysmal dilatation7cases, coronary artery with abnormal origin2cases, coronary-pulmonary artery with fistula 1case, dilated cardiomyopathy1case, unknowing cause pericardial effusion3cases, ventricular myxoma1case, congenital heart disease with atrial septal defect1case. Patients with pneumonia and pleuritis16cases, lung carcinoma2cases, metastasis of bone combined with fracture2cases, lymphoma1case, hamartoma1case,103cases were normal. Subjective score of image quality of the voltage120kV group and100kV group had no statistical significance (P>0.05). There were no statistical significance (P>0.05) in enhanced CT value of ascending aorta, descending aorta, pulmonary artery and coronary artery (RCA、LM、LAD、 LCX). Imaging noise and scan length also had no statistical significance (P>0.05). The difference was statistically significant (P<0.05) in CTDIvo、DLP、ED. The effective radiation dose of the voltage100kV group was lower than that of the voltage120kV group.Conclusion1. The one-time examination of triple-rule-out (TRO) dual-source CT for pulmonary artery, coronary artery and aorta can be finished. Meanwhile, the diseases of large vessels and coronary artery can be found. In addition, the diseases of lung, pleura and bone can be spotted. This kind of skill is a noninvasive and very reliable examination which is greatly useful for searching the causes and diagnosis and differential diagnosis of acute chest pain.2. Both voltage120kV and voltage100kV examination of triple-rule-out (TRO) dual-source CT can appear clearly three-main vessels. In the case of uncontrolling the heart rate, the quality of pictures of coronary artery are better than that of64-slice spiral CT and ensure the success rate of examination of the patients of acute chest-pain. When low tube voltage (100kV) was used, the quality of pictures of three-main vessels didn’t fall and image noises were within acceptable limits.3. Low tube voltage (100kV) examination of triple-rule-out (TRO) combined with CARE Dose4D and ECG-pulsing further decrease the radiation dose and impairment for the patients under the case of protecting the quality of pictures.All in all, this study showed that one-time examination of triple-rule-out (TRO) dual-source CT could perfectly appear pulmonary artery, coronary artery and aorta, and the low voltage (100kV) scan technique can further reduce the radiation dose under the condition of unaffecting the diagnosis, which is very helpful for clinical treatment, and can be used as the first choice, as well as is suitable for use in the patients with acute chest-pain widely.