Objective To explore the application value of test bolus combined with a high-flow rate injection scheme in improving the quality of thyroid CT enhancement images.Methods A total of 126 patients who underwent thyroid plain scan and enhanced CT were selected.Among them,63 underwent conventional examination methods(control group),while the remaining 63 patients received test bolus and high-flow rate injection scheme(experimental group).Objective evaluation included the signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),thyroid enhancement rate,thyroid parenchyma-cancer difference,artifact index(AI)of the two groups of arterial phase images,thyroid enhancement rate of the two groups of venous phase images,and contrast agent dose of the two groups were all compared.Statistical analysis was performed via independent sample t-test or Mann-Whitney U test.Subjective evaluation included the evaluation of thyroid display in two groups of arterial phase images was conducted via the 4-point method,followed by the implementation of the Mann-Whitney U test.Results The SNR,CNR,thyroid enhancement rate,thyroid parenchyma-cancer difference,and AI in the arterial phase images of the experimental group were all significantly superior to those of the control group(P＜0.05).There was no statistically significant difference in the thyroid enhancement rate in the venous phase between control group and experimental group(P＞0.05);The contrast agent dose of the experimental group was significantly lower than that of the control group(P＜0.01).The thyroid display score observed in the arterial phase images of the experimental group was significantly higher than that of the control group(P＜0.01).Conclusion Using a test bolus combined with a high-flow rate injection scheme can significantly improve the image quality of thyroid CT enhancement.