PURPOSE: To evaluate the contrast enhancement patterns and mass detection rate of metastatic adenocarcinoma of the liver in the early and late phase of spiral bolus dynamic CT. MATERIALS AND METHODS: Two-phase spiral bolus dynamic CT of the liver was performed on 34 patients with clinically or pathologically proved metastatic adenocarcinoma of the liver after bolus administration of 120 mL of contrast material intravenously. CT scanning was started at 45 seconds and 6 minutes after I~eginning of injection in 23 patients, and at 35 seconds and 3 minutes in another 11 patients. The enhancement patterns of the tumors were classified into 6 types compared with attenuation of surrounding normal liver parenchyma, as diffusely high, peripherally high, centrally high, mixed, iso, diffusely low. The enhancement patterns of 76 tumors in 34 patients were analysed. RESULTS: In the early phase, peripherally high attenuation was seen in 34(45%) and diffusely low attenuation in 23(30%). In the late phase, diffusely low attenuation was seen in 27(36%) followed by iso and mixed in 14 (18%), in each, and peripherally high in 13(17%). The appearances of enhancement pattern from the early to the late phase were variable. 12(16%) were diffusely low in both phases, 11(14%) were peripherally high in the early phase and diffusely low in the late phase, and 10(13%) were peripherally high in both phases. Number of tumor lesions detected were more in the early phase in 12(35%)patients, and in the late phase in 3(9%) patients. CONCLUSION: Metastatic adenocarcinoma of the liver showed variable enhancement patterns in the early and late phases of spiral bolus dynamic CT, although the most common pattern was peripherally high in early phase, and diffusely low in the late phase. The detection rate of masses was higher in early phase than late. The two-phase spiral bolus dynamic CT should be good method in detection and differential diagnosis of metastatic adenocarcinoma of the liver.