低剂量血管成像在冠状动脉疾病检查中应用的研究

目的 对收集的CT冠状动脉成像图应用噪声添加软件进行处理，模拟出不同球管电流条件下的图像数据，评估出冠状动脉最适合的低球管电流。方法 选择2013年4～10月在山西医科大学第一医院放射科行冠状动脉血管成像（CCTA）检查且确诊患有冠状动脉疾病的42例患者的CTA横断面图像为研究对象。根据患者体重指数（BMI）〉24kg／m^2和≤24kg／m^2分为A、B两组，每组各21例。应用噪声添加软件分别模拟出150、250、350、450、550mA5种低剂量图像。使用秩和检验与χ^2检验，对不同辐射剂量下的病灶显示情况和影像质量进行对比评价，得出既能使患者接受最小辐射剂量又能满足临床诊断需求的最适球管电流。结果 A组的患者最适低球管电流为350mA．B组患者最适低球管电流为250mA。辐射剂量分别为原管电流辐射剂量的49％和33％。结论 在进行CCTA检查中。BMI〉24kg／m^2和≤24kg／m^2的患者最适低球管电流分别为350mA和250mA，采用减低球管电流的方法 能够很大程度的降低患者接受的辐射剂量，同时获得满足临床要求的图像质量及诊断结果 。

Application research of low doses of CTA in the detection of the coronary artery disease

Objective To process the collected CT coronary angiography images by noise addition tool in order to imitate the image of different tube current and obtain the best tube current. Methods 42 CCTA cross-sectional images of patients with coronary artery disease from April to October 2013 in the Radiology Department of the First Hospital of Shanxi Medical University as the study objects. All of them were divided into group A （BMI〉24 kg/m^2） and group B （BMI≤24 kg/m^2） according to BMI, with 21 cases in each group. Then 5 sets of lower dose scans with tube current of 150, 250, 350, 450 and 500 mA were simulated by noise addition tool. And the ranked data were analyzed by ranksum test and enumeration data were analyzed by chi-square test. Then the image quality and the display situation of lesions of different radiation doses were evaluated, the best tube current to satisfy the need of diagnosis was found. Results The best tube current for the patients in group A and B were 350 mA and 250 mA respectively, radiation does were the original tube current radiation doses of 49% and 33%. Conclusion During the CCTA inspection, the low ball tube current with 350 mA and 250 mA are the most suitable tube current for patients with BMI〉24 kg/m^2 and ≤24 kg/m^2 respectively, the method for reducing the tube current could reduce the radiation doses of patients accepted greatly, while satisfy the clinical requirement of image quality and diagnosis at the same time.