Objective To probe the blood supply of liver metastasis by celiac artery,proper hepatic artery DSA.portal vein perfusion CT during superior mesenteric arterial poaography(PCTAP).Methods One hundred patients with liver metastases were examined prospectively by plain CT scan,multiphase enhanced CT scan,celiac arteriography and proper hepatic artefiography.Of them,56 patients were examined by PCTAP.All primary lesions wero confirmed by operation and(or)pathology examination.In order to investigate the blood supply of metastasis lesions.the software of Photoshop Was used to obtain the time-attenuation cugves(TDC)of tumor center,tumor edge,portal vein and normal liver parenchyma adjacent to the tumor to talculate liver perfusion for DSA image analysis,while a deconvolution model from CT perfusion software Was designed for the dual blood supply.Results DSA findings:TDC of proper hepatic arteriography showed:the mean peak concentration(K value)in tumor centers was(67±12)%,and it was(76±15)%for peritumor tissue,(51±10)%in normal liver parenchyma.TDC of celiac arteriogaphy showed that the contrast concentration of tumor centers and tumor edge increased fast in early stage.then maintained a slight upward plateau,in the meanwhile,the contrast concentration of normal liver parenchyma kept increasing slowly.PCTAP findings:tumors exhibited no enhancement during 30 s continued scans.Conciusion The blood supply of liver metastasis mainly comes from hepatic artery,but barely from portal vein.