To compare the image quality and radiation dose of 256-slice spiral CT full iterative model reconstruction (IMR) and hybrid iterative reconstruction (iDose4) in low radiation dose liver enhancement. And explore the value of (MRI) dynamic enhancement in the diagnosis of liver cancer.Methods From January 2021 to October 2021, 40 patients who underwent liver enhanced plain scan at the same time using conventional doses and three-phase enhancement using relatively low-dose CT scan and MRI dynamic enhancement, and were pathologically diagnosed with liver cancer were collected. The slice images were reconstructed by the hybrid iterative algorithm (iDose4) and the full model iterative algorithm (IMR) respectively, and the noise, signal-to-noise ratio, contrast signal-to-noise ratio and radiation dose indicators of the two groups were compared. The detection rate of liver cancer was compared with the dynamic enhancement of MRI. analyze. Results All images could meet the diagnostic requirements under the two reconstruction group algorithms. Noise, SNR and CNR comparison difference between two groups had statistical significance (P＜0.05). The image quality of group B was better than that of group A. Three periods of enhanced radiation dose is scan has significantly reduced, comparative differences are statistically significant (P＜0.05). The low contrast resolution and diagnostic confidence degree of group B was higher than that of group A (P＜0.05). The image distortion degree of group B was lower than that of group A (P＜0.05). MRI dynamic contrast enhanced three groups of liver cancer there was no statistically significant difference detection rate (P＞0.05), but IMR reconstruction technique to subtle signs show more clearly.Conclusion The full iterative reconstruction (IMR) technique in 256-slice spiral CT can improve the image quality of liver low-dose enhanced scan, and has a certain application value in the clinical diagnosis of liver cancer.