Optimization of contrast agent dose for 320-slice spiral computed tomography (320-slice CT) of coronary artery

Guo Jing; Zhang Na; Li Shuofeng

doi:10.3969/j.issn.1674-4055.2017.08.23

Abstract：Objective To analyze the optimize dose of contrast agent during imaging of 320-slice spiral computed tomography (320-slice CT) of coronary artery.Methods The patients with suspected coronary artery lesions (n=90, male 53, female 37, aged from 28 to 87 and average age=58.7±6.2) were chosen from the Central Hospital of Cangzhou City from June 2013 to Aug. 2013. All patients were randomly divided into group A (n=30, dose of contrast agent=0.7 ml/kg), group B (n=30, dose of contrast agent=0.6 ml/kg) and group C (n=30, dose of contrast agent=0.5 ml/kg) with injection concentration in 350 mgI/ml and injection rate in 5.0 ml/s. All groups were given coronary CT examination, and image quality was reviewed. At the same time all groups were given examination of coronary angiography (CAG).Results The average CT value of right distal and proximal coronary artery, proximal left circumflex of coronary artery (LCX), proximal left anterior descending branch and left main coronary artery (LMCA) was lower in group C than that in groups A and B (all P<0.05), and the difference in the value had no statistical significance between group A and group B (all P>0.05). There were 957 (92.7％) grade Ⅳ images, 54 (5.2％) grade Ⅲ images and 21 (2.1％) grade Ⅱ images, and image quality was higher. After CAG examination in group B, there were 219 stenosis segments (≥50％) in coronary artery showed by CT, 2 in LMCA, 71 in right coronary artery, 57 in LCX and 89 in left anterior descending branch. The sensitivity of CT was 92.6％, specificity was 96.1％, negative predictive value was 98.0％, and positive predictive value was 86.3％.Conclusion The optimal dose of contrast agent is 0.6 mg/kg with injection concentration in 350 mgI/ml during imaging of 320-slice CT of coronary artery, and the dose is highly accuracy in diagnosis of coronary artery lesions.