Objective：To investigate the advantages of the P3T modularized and personalized injection technique in “one-stop-shop” cardiac inspection by dual-source computed tomography（CT）. Methods：Forty patients undergoing “one-stop-shop” cardiac inspec－tion were randomly assigned to two groups. The control group received a conventional dosage regimen based on the patients’ body mass. The experimental group received a dosage regimen calculated by the P3T modularized and personalized injection technique（Medrad，Inc.） based on the patients’ condition. Both groups received “one-stop-shop” cardiac inspection by a second-generation dual-source CT scanner（Siemens，Inc.） using the contrast medium with an iodine concentration of 370 mg/mL（Ultravist）. The image quality and contrast medium dosage were compared between the two groups with other parameters remaining the same. Results：All patients in the two groups were successfully inspected. There were no significant differences in general information between the two groups（P>0.05）. In terms of the quality of coronary artery images，there were no significant differences in the CT values of the proximal or middle coronary arteries between the two groups（the proximal right coronary artery P=0.829，the middle right coronary artery P=0.837，the proximal anterior descending coronary artery P=0.927，the middle anterior descending coronary artery P=0.731，the proximal circumflex coronary artery P=0.637，the middle circumflex coronary artery P=0.949）；there were also no significant differences in the CT values of the proximal and middle segments of coronary arteries between the two groups（the proximal and middle segment of the right coronary artery P=0.991，the proximal and middle segment of the anterior descending coronary artery P=0.512，the proximal and middle segment of the circumflex coronary artery P=0.164）；the CT values of the distal coronary arteries were significantly higher in the experimental group than in the control group（the distal right coronary artery P=0.016，the distal anterior descending coronary artery P=0.012，the distal circumflex coronary artery P=0.024）；the CT values of the middle distal and proximal distal coronary arteries were significantly lower in the experimental group than in the control group（the middle distal segment of the right coronary artery P=0.000，the proximal distal segment of the right coronary artery P=0.011，the middle distal segment of the anterior descending coronary artery P=0.002，the proximal distal segment of the anterior descending coronary artery P=0.002，the middle distal segment of the circumflex coronary artery P=0.000，the proximal distal segment of the circumflex coronary artery P=0.006）. In terms of the image quality in the myocardial perfusion analysis，the number of beam-hardening artifacts caused by the contrast medium was significantly lower in the experimental group than in the con－trol group（44 vs. 69）；there were no significant differences in the mean iodine concentrations of the normal myocardium in the basal or middle layer of the heart during diastole between the two groups（the basal layer of the heart P=0.236，the middle layer of the heart P=0.624）；the mean iodine concentrations of the normal myocardium in the apical layer and apical segment during diastole were sig－nificantly higher in the experimental group than in the control group（the apical layer of the heart P=0.012，the apical segment of the heart P=0.014）. There was no significant difference in the contrast medium dose between the two groups（P=0.734）. Conclusion：In the “one-stop-shop” cardiac inspection，the P3T modularized injection technique（Medrad，Inc.） can effectively improve the image quality by effectively demonstrating the distal and minor branches of the coronary arteries and reducing the false-positive results caused by the contrast medium-induced beam-hardening artifacts during the myocardial perfusion analysis.