AIM: To explore portal hypertension and portosys-temic shunts and to stage chronic liver disease (CLD) based on the pathophysiology of portal hemodynam-ics. METHODS: Per-rectal portal scintigraphy (PRPS) was performed on 312 patients with CLD and liver angio-scintigraphy (LAS) on 231 of them. The control group included 25 healthy subjects. We developed a new model of PRPS interpretation by introducing two new parameters,the liver transit time (LTT) and the circu-lation time between right heart and liver (RHLT). LTT for each lobe was used to evaluate the early portal hypertension. RHLT is useful in cirrhosis to detect liver areas missing portal in? ow. We calculated the classical per-rectal portal shunt index (PRSI) at PRPS and the hepatic perfusion index (HPI) at LAS. RESULTS: The normal LTT value was 24 ± 1 s. Abnor-mal LTT had PPV = 100% for CLD. Twenty-seven non-cirrhotic patients had LTT increased up to 35 s (median 27 s). RHLT (42 ± 1 s) was not related to liver disease. Cirrhosis could be excluded in all patients with PRSI < 5% (P < 0.01). PRSI > 30% had PPV = 100% for cirrhosis. Based on PRPS and LAS we propose the clas-sifi cation of CLD in 5 hemodynamic stages. Stage 0 is normal (LTT = 24 s,PRSI < 5%). In stage 1,LTT is increased,while PRSI remains normal. In stage 2,LTT is decreased between 16 s and 23 s,whereas PRSI is increased between 5% and 10%. In stage 3,PRSI is increased to 10%-30%,and LTT becomes undetect-able by PRPS due to the portosystemic shunts. Stage 4 includes the patients with PRSI > 30%. RHLT and HPI were used to subtype stage 4. In our study stage 0 had NPV = 100% for CLD,stage 1 had PPV = 100% for non-cirrhotic CLD,stages 2 and 3 represented the transition from chronic hepatitis to cirrhosis,stage 4 had PPV = 100% for cirrhosis. CONCLUSION: LTT allows the detection of early por-tal hypertension and of opening of transhepatic shunts. PRSI is useful in CLD with extrahepatic portosystemic shunts. Our hemodynamic model stages the evolution of portal hypertension and portosystemic shunts. It may be of use in the selection of patients for interferon therapy. AIM: To explore portal hypertension and portosys-temic shunts and to stage chronic liver disease (CLD) based on the pathophysiology of portal hemodynamics. METHODS: Per-rectal portal scintigraphy (PRPS) was performed on 312 patients with CLD and liver angio The control group included 25 healthy subjects. We developed a new model of PRPS interpretation by introducing two new parameters, the liver transit time (LTT) and the circu-lation time between right heart and liver RHLT is useful in cirrhosis to detect liver areas missing portal in? Ow. We calculated the classical per-rectal portal shunt index (PRSI) at PRPS and the hepatic RESULTS: The normal LTT value was 24 ± 1 s. Abnor-mal LTT had PPV = 100% for CLD. Twenty-seven non-cirrhotic patients had LTT increased up to 35 s (median 27 s ) RHLT (42 ± 1 s) was not related to liver disease. Cirrhos PRSI> 30% had PPV = 100% for cirrhosis. Based on PRPS and LAS we propose the clas-sifi cation of CLD in 5 hemodynamic stages. Stage was likely to be excluded in all patients with PRSI <5% (P <0.01) 0 is normal (LTT = 24 s, PRSI <5%) In stage 1, LTT is increased, while PRSI remains normal. In stage 2, LTT is decreased between 16 s and 23 s, 10%. In stage 3, PRSI is increased to 10% -30%, and LTT becomes undetectable by PRPS due to the portosystemic shunts. Stage 4 includes the patients with PRSI> 30%. RHLT and HPI were used to subtype stage 4. In our study stage 0 had NPV = 100% for CLD, stage 1 had PPV = 100% for non-cirrhotic CLD, stages 2 and 3 represented the transition from chronic hepatitis to cirrhosis, stage 4 had PPV = 100% for cirrhosis CONCLUSION: LTT allows the detection of early por-tal hypertension and of opening of transhepatic shunts. PRSI is useful in CLD with extrahepatic portosystemic shunts. Our hemodynamic model stages the evolution of portal hypertension and portosystemic shunts. It may be of use in the selection of patients for interferon therapy.