Abstract: Objective: To evaluate the clinical application value of dual-energy computed tomography (DECT) combined with a 3 mL/s contrast agent injection rate in comparison with single-energy CT (SECT) using a 2.5 mL/s injection rate by comparing the sizes of contrast agent artifacts in the axillary vein during the arterial phase of chest and abdomen enhanced CT examinations. Methods: A retrospective study was conducted on 77 cases of chest and abdomen enhanced CT scans that were performed from January to November 2024 at our hospital. These scans were performed on the same subjects using both dual-energy (experimental group) and single-energy (control group) CT techniques. The differences between the two groups were compared in terms of axillary vein contrast agent artifact size, arterial phase enhancement, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), subjective evaluations of artifact severity, and overall image quality. The subjective evaluations of artifact severity and image quality were independently assessed by two radiologists. Results: The subjective and objective scores for axillary vein contrast agent artifacts in the experimental group were significantly lower than those in the control group. The arterial CT values in the experimental group were higher than those in the control group. The SNR and CNR in non-artifact-affected regions, such as bone, muscle, and adipose tissue, in the experimental group were not lower than those in the control group, whereas the radiation dose was significantly lower in the experimental group. The subjective scores for artifact severity were better in the experimental group, and the subjective image quality scores in the experimental group were superior to those in the control group. The interobserver agreement between the two radiologists was high. Conclusion: Dual-energy CT combined with a 3.0 mL/s contrast agent injection rate significantly reduces contrast agent artifacts in the axillary vein, improves image quality, and lowers the radiation dose, compared with single-energy CT with a 2.5 mL/s injection rate, demonstrating a better clinical application value in chest and abdomen enhanced CT examinations.