Abstract: Purpose: To assess the clinical efficacy of integrating deep learning reconstruction (DLR) with contrast-enhancement-boost (CE-boost) in 80 kVp head and neck CT angiography (CTA) using substantially lowered radiation and contrast medium (CM) doses, compared to the standard 100 kVp protocol using hybrid iterative reconstruction (HIR). Methods: Sixty-six patients were prospectively enrolled and randomly assigned to one of two groups: the low-dose group (n=33), receiving 80 kVp and 28 mL contrast medium (CM) with a noise index (NI) of 15; and the regular-dose group (n=33), receiving 100 kVp and 40 mL CM with an NI of 10. For the low-dose group, images underwent reconstruction using both hybrid iterative reconstruction (HIR) and deep learning reconstruction (DLR) at mild-, standard-, and strong-strength levels, both before and after combination with contrast enhancement-boost (CE-boost). This generated eight distinct datasets: L-HIR, L-DLR_mild, L-DLR_standard, L-DLR_strong, L-HIR-CE, L-DLR_mild-CE, L-DLR_standard-CE, and L-DLR_strong-CE. Images for the regular-dose group were reconstructed solely with HIR (R-HIR). Quantitative analysis involved calculating and comparing CT attenuation, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) within six key vessels: the aortic arch (AA), internal carotid artery (ICA), external carotid artery (ECA), vertebral arteries (VA), basilar artery (BA), and middle cerebral artery (MCA). Two radiologists independently assessed subjective image quality using a 5-point scale, with statistical significance defined as P < 0.05. Results: Compared to the regular-dose group, the low-dose protocol achieved a substantial reduction in contrast media volume (28 mL versus 40 mL, a 30% decrease) and radiation exposure ((0.41±0.08) mSv versus (1.18±0.12) mSv, a 65% reduction). Both L-DLR_standard and L-DLR_strong delivered comparable or superior SNR and CNR across all vascular segments relative to R-HIR. However, subjective image quality scores for L-DLR at all strength levels fell below those for R-HIR (all P < 0.05 for both readers). Combining CE-boost with the low-dose protocol significantly enhanced the objective image performance of L-DLR_strong-CE (all P < 0.05) and produced subjective image scores comparable to R-HIR (reader 1: P=0.15; reader 2: P=0.06). Conclusion: When compared to the standard 100 kVp head and neck CTA, the combination of the DLR and CE-boost techniques at 80 kVp can achieve a 30% reduction in contrast dose and a 65% reduction in radiation dose, while maintaining both objective and subjective image quality.