Objective: 、To compare the value of the arterialportal venous and equilibrium phase scans in the diagnosis of hepatocellular carcinoma (HCC)

and choose the optimal scan phase and protocol. Methods: The per and postcontrast CT scanning of the entire liver in 48 patients with HCC was carried out with a helical CT scanner. The contrast material was injected at a rate of 3ml/s

followed by sequential arterial

portal venous and equilibrium phase scans of the liver. The number of the detected lesions was calculated in each phase and the characterization of lesions in each phase was also observed. Results: The detection rate of lesions in arterial

portal venous and equilibrium phase scans was 91.9%

76.9% and 78.8% respectively

the significant difference was found between arterial and portal venous phase or equilibrium phase

but no difference between the portal venous and equilibrium phases. Conclusion: The arterial phase scan has the greatest value in the detection of HCC

and there is no difference between the portal venous phase and equilibrium phase scans. The dual - phase scans (arterial and portal venous phase ) should be a standard and routine methods in the detection of HCC

and for atypical cases

the equilibrium phase scan is needed to aid in lesion’s characterization.