| Background and purposecardiovascular disease started with China’s entry into the aging increases gradually, coronary heart disease as a cardiovascular disease a family member, it is the trend of the progress has been rising, its incidence and mortality of both at inland and abroad have already occupied are most important position. Selective coronary angiography (selective coronary angiography, SCA) has been considered to be the gold standard since the advent of coronary angiography imaging. in recently years, with the continuous development of multi-slice CT, multi-slice CT coronary angiography for its non-invasive, simple and convenient, more and more clinical applications, a large number of examinations lead to contrast medium used more widely, CIN(Contrast Induced Nephrology, CIN) has become a hospital acquired acute kidney injury of the third big reason, how to use the right contrast medium injection scheme began to attention and exploration, and a lot of research for formulating the coronary angiography imaging optimal injection contrast medium scheme, but has not been a standard appear. Tatsugami believe that 64-slice CT coronary angiography imaging injection and weight than the contrast volume for 0.7 ml/kg, injection contrast medium time 10 s, dual-source Flash CT coronary angiography high-pitch imaging to further reduce the time to the milliseconds, the author discusses the can meet the premise of clinical diagnosis of maximum reduce the volume of the contrast medium.ObjectiveTo evaluate the dual-source Flash CT high-pitch coronary angiography imaging low dose contrast medium after optimization of image qualitymaterials and methodsPatients of 95 underwent coronary CTA, in accordance with the different contrast medium volume and body weight ratio were randomly divided into three groups of patients with heart rate≤65 beats/min, cardiothoracic ratio≤0.5, transthoracic echocardiographic assessment of ejection fraction≥55%, using the scan mode ECG-gated pitch 3.4, tube voltage 100kV, automatic modulation maximum tube current 370mAs.contrast medium using Ultravist 370mgI/ml A group of 30 cases, 34 cases of Group B, group C 3lcases, in accordance with the ratio of the contrast medium volume and body weight were 0.7ml/kg,0.6ml/kg and 0.5ml/kg contrast volume equal to body weight multiplied by the respective ratio. Injection flow rate of 5-6ml/s, and normal saline 50-60ml.Measuring the CT value of the superior vena cava, pulmonary artery, aorta, left atrium, left ventricle, coronary various branches of blood vessels and myocardium under the walls of the original image, using SPSS 17.0 software on the data obtained were statistically analyzed by ANOVA,The variance analysis between the three groups of patients, the amount of contrast agent, radiation dose, the inferior vena cava, pulmonary angiography, aorta, myocardial inferior wall, coronary angiography and its branches of blood vessels within the CT value, with a mean±variance If the difference was statistically significant differences between the pairwise comparison were evaluated by LSD.χ2 test to compare among the three groups of coronary angiography image quality grading show the number of segments.The application of the kappa test to determine the consistency of the two evaluators score.P<0.05 for the difference was statistically significant. Resultsthe basic data of 95 randomly selected patients showed no significant differences among the three groups; CT values in the superior vena cava vascular differences between groups was statistically significant (F=10.537,p=0.139) in group A and B differences between the groups was statistically significant (p=0.002), the difference was not statistically significant (p=0.139) between group B and group C, there was significant difference between group A and group C (p=0.000); pulmonary artery CT values were statistically significant differences between groups (F=17.130, p= 0.000) difference was statistically significant (p=0.000) between group A and group B, the difference between group B and group C non-statistically significant (p 0.069), the difference between group A and group C was statistically significant (p= 0.000); within the blood vessels of the left atrium CT value differences between groups was statistically significant (F=5.139, p=0.008).no significant difference between group A and group B(p=0.057), the difference was not statistically significant (p=0.181) between group B and group C, there was significant difference between group A and group C (p=0.002); left ventricular intravascular CT value differences between groups was statistically significant (F=4.309, p=0.016) between group A and group B, the difference was not statistically significant (p= 0.334), group B and was no significant difference (p=0.05) between group C, the difference between group A and group C was statistically significant (p= 0.005), ascending aorta and descending aortic CT value differences between groups without statistically significant.CT value of coronary branch vessels was no significant difference among the groups.Each group between myocardial wall CT values were 81±21HU,82±13HU,82±17HU, differences between groups was not statistically significant (F=0.043, p= 0.958).The contrast dose groups were 36±6ml,44±8ml,47±8ml, statistically significant differences between groups (F=14.628, P=0.000), no statistical difference between group A and group B significance (P= 0.100) in group A and group C, the difference between group B and group C was statistically significant (p =0.000).Ascending aortic image noise followed 20.4±5.8HU,21.1±5.6HU,19.7±6.2HU, no significant differences between groups (p> 0.356).A total of 748 segments of coronary artery diameter≥1.5 mm in three groups of patients,374 segments of group A and 30 patients,214 outstanding, accounting for 57.2%; good 154,41.2%; medium of paragraph 4, accounted for 1.1%; difference of two segments, accounting for 0.5%; image quality for a good total of 368 segments, accounting for 98.4%.Group B,34 patients 424 coronary artery segments, score of 234 was excellent, accounting for 55.2%; good 182, accounting for 42.9%; medium segment, accounting for 1.4%; difference of two segments, accounting for 0.5% and a total of 416 segments, excellent image quality, accounting for 98.1%.Group C 31 patients with 386 coronary artery segments, the score was excellent in 219, accounting for 56.7%; good 159, accounting for 41.2%; paragraph 6 medium, accounting for 1.6%; difference between two segments accounted 0.5% and a total of 378 segments, excellent image quality, accounting for 97.9%.The coronary artery image quality grading good number of segments the difference was not statistically significant (x 2 =0.586, p=0.965) among the groups record coronary length of the radiation dose range of DLP 43～71mGy.cm, the radiation dose difference between the groups non-statistically significant.Conclusion1. dual-source Flash CT high-pitch coronary angiography imaging in meet the premise of clinical diagnosis choose contrast medium volume and body weight ratio is 0.5 ml/kg maximum degree of reduced the amount of contrast medium2.dual-source Flash CT high-pitch coronary angiography imaging radiation dose can low to 1 mSv less than.3.Contrast volume should be used to be according to contrast volume and body weight than personalized injection. 4.dual-source Flash CT hing-pitch coronary angiography imaging can assure already low radiation dose, and can ensure low contrast doses, can be used as the first choice of early coronary heart disease high-risk groups screening method and means. |
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