Staging of portal hypertension and portosystemic shunts using dynamic nuclear medicine investigations

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.

Nuclear medicine dynamic investigations in the diagnosis of Budd-Chiari syndrome

AIM:To investigate the hepatic hemodynamics in the Budd-Chiari syndrome(BCS) using per-rectal portal scintigraphy(PRPS) and liver angioscintigraphy(LAS).METHODS:Fourteen consecutive patients with BCS were evaluated by PRPS between 2003 and 2012.Ten of them underwent LAS and liver scan(LS) with Tc-99m colloid.Eleven patients had clinical manifestations and three were asymptomatic,incidentally diagnosed at PRPS.The control group included 15 healthy subjects.We used new parameters at PRPS,the liver transit time of portal inflow and the blood circulation time between the right heart and liver.PRPS offered information on the hepatic areas missing venous outflow or portal inflow,length and extent of the lesions,open portosystemic shunts(PSS),involvement of the caudate lobe(CL) as an intrahepatic shunt and flow reversal in the splenic vein.LAS was useful in the differential diagnosis between the BCS and portal obstructions,highlightingthe hepatic artery buffer response and reversed portal flow.LS offered complementary data,especially on the CL.RESULTS:We described three hemodynamic categories of the BCS with several subtypes and stages,based on the finding that perfusion changes depend on the initial number and succession in time of the hepatic veins(HVs) obstructions.Obstruction of one hepatic vein(HV) did not cause opening of PSS.The BCS debuted by common obstruction of two HVs had different hemodynamic aspects in acute and chronic stages after subsequent obstruction of the third HV.In chronic stages,obstruction of two HVs resulted in opening of PSS.The BCS,determined by thrombosis of the terminal part of the inferior vena cava,presented in the acute stage with open PSS with low speed flow.At least several weeks are required in the obstructions of two or three HVs for the spontaneous opening of dynamically efficient PSS.The CL seems to have only a transient important role of intrahepatic shunt in several types of the BCS.CONCLUSION:Dynamic nuclear medicine investigations assess the extent and length of hepatic venous obstructions,open collaterals,areas without portal inflow,hemodynamic function of the CL and reverse venous flow.