Abstract: Objective:To compare contrast-induced hardening artifacts of the axillary vein during the arterial phase between dual-energy CT (DECT) and single-energy CT (SECT) with different contrast agent injection rates in thoracoabdominal enhanced CT examinations, and to assess their clinical value. 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 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. Subjective scores for hardening artifacts were significantly better in the experimental group, and image quality scores in regions outside the axillary vein hardening artifacts were non-inferior to those of the control group. Interobserver agreement between the two radiologists was high. Conclusion: Dual-energy CT blended images combined with a contrast injection rate of 3 mL/s can effectively reduce contrast-induced hardening artifacts, improve image quality, and lower radiation dose in thoracoabdominal enhanced CT examinations, offering superior clinical applicability.