ABSTRACT
Objective: To investigate the effect of individualized contrast administration in improving the enhancement homogeneity in vessels and image quality in coronary CT angiography (CCTA). Methods: Sixty CCTA patients were randomly divided into two groups with different contrast injection protocols: treatment group (n=30) was treated with weight-dependent injection protocol at 22 mg/(g•s) of idion, injection velocity=body mass×22/contrast agent concentration. Control group (n=30) was treated with a different injection protocol. The iodine flow rate in this group was determined by patient body mass index (BMI), iodine flow rate=1.2 g/s, 1.4 g/s and 1.6 g/s. Injection flow rate= iodine flow rate/contrast agent concentration. Theiohexol (350 mg/mL) was used in both groups, and the injection time was fixed at 10 s and contrast agent dose=injection velocity×injection time. The other scanning parameters were the same. The enhancement change rate in AS and the three major arteries was calculated for the patient population. The subjective image quality scores were also compared. Results: The change rates of vascular enhancement at interested blood vessels in treatment group (12.9%, 11.8%, 11.0% and 11.1%, respectively) were significantly lower than those in in control group (23.3%, 18.7%, 16.7% and 20.5%, respectively) (P=0.001). There was no significant difference between the two groups in subjective image quality score (P=0.095). Conclusion: Individualized contrast injection protocol in CCTA can provide us with a more uniform enhancement in coronary arteries, and improve the overall image quality.
