Study On The Effect Of Preoxygenation On Imaging Quality Of MSCT Coronary Angiography

It is very important for the diagnosis of accuracy of coronary artery disease(CAD). The image qulity of the multi-slices CT (MSCT) coronary angiography. All patients who were pretest likelihood of CAD were randomly divided into two groups which was with and without preoxygenation. Volume rendering (VR)and maximum intensity projection (MIP)were used to evaluate the image quality of right coronary artery and left anterior descending artery. To detecte the effect of preoxygenation on imaging quality is full of valuation, and could provide the evidence to clinical practice.Objective: To evaluate the effect of preoxygenation on image quality of MSCT coronary angiography in patients who were to be CAD..Materials and methods: 35-65 year-old patients who had no history of stent planting, cardiac surgery, heart rhythm irregularities were included in our study, and the value of body mass was 20~30kg/m2. The heart rate was controlledwith metoprolol orally to be less than 65bpm. A total of 161 patients(111 men, 50 women;49.6±6.9 years) who underwent MSCT coronary angiography were enrolled. All patients were randomly divided into two groups, Those with and without preoxygenation were as the parameters of MSCT coronary angiography of scanner (GE HealthCare , LightSpeed 16) following: 16-detector-row;collimation, 0.625 mm;gantry rotation time, 500ms;120 kV;and effective milliampere setting based on body mass, 370-410. All data were reconstructed in75% R-R interval. Mann-Whitney U analysis were used to evaluate the image quality, P value which less than or equals to 0.05 was considered as significant.Results: Both groups have the same clinical situation. The image quality had no statistically significant difference between the group with preoxygenation and the group without preoxygenation. (VR, Z = -0.899, P = 0.369;MIP high scale ,right coronary proximal segment, Z = -0.934, P = 0.350;right coronary middle segment, Z = -1.221, P = 0.222;right coronary distal segment, Z = 0.000, P = 1.000;left anterior decending proximal segment, Z = -1.039, P = 0.299;left anterior decending middle segment, Z = -1.366 ,P = 0.172;left anterior decending distal segment, Z = -1.474, P = 0.141. MIP low scale, right coronary proximal segment, Z=-1.444, P = 0.350;right coronary middle segment, Z= -1.099, P = 0.272;right coronary distal segment, Z=-0.099, P = 0.921;left anterior decending proximal segment, Z = -1.474, P = 0.141;left anterior decending middle segment, Z = -0.435, P = 0.664;left anterior decending distal segment, Z=-1.014, /> = 0.311) .Conclusion: The image quality of MSCT coronary angiography didn't improve obviously when using the procedure of deep inspiration once and holding breath with mask oxygen, and heart rate controlled with P-blocker orally.