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, highlighting the 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.

The non-conventional use of 99mTc-Tetrofosmine for dynamic hepatobiliary scintigraphy.

BACKGROUND: Classic dynamic hepatobiliary scintigraphy (DHBS) is commonly performed with 99mTc-Iminodiacetic Acid (IDA) derivatives and represents a non-invasive diagnosis method for biliary dyskinesia, fistulas, surgical anastomosis, etc (1). This study assesses the possibility of performing DHBS with 99mTc-Tetrofosmine (TF), a radiopharmaceutical (RF) dedicated to myocardial perfusion scintigraphy (MPS), but being excreted through the liver. The possibility to use 99mTc-TF for DHBS may be important in situations when the standardized RF for this procedure (IDA derivatives) is not available. MATERIAL AND METHODS: We performed DHBS for 30 patients referred for investigation by internal medicine and surgery departments. The patients had been fasting for 12 hours. The dynamic investigation started simultaneously with the intravenous (IV) administration of 37-110 MBq (1-3 mCi) 99mTc-TF. Dynamic images were recorded for 30-45 minutes, one image per minute, followed by static scintigraphy at 1 h, 1.5 h, 2 h, and 3 h after IV injection. RESULTS: The quality of scintigraphic images of the liver and biliary tree obtained at DHBS with 99mTc-TF ensured the correct diagnosis of biliary dyskinesia, stasis, stenosis, and fistulas. CONCLUSIONS: DHBS using 99mTc-TF is justified by the image quality and by the good cost/benefits ratio. Because the IDA derivatives are not always available, this finding may be important for medical practice. 99mTc-TF evacuated through the bile duct allows DHBS interpretation, while the necessary dose is approximately 8 to 20 times smaller than that used for myocardial perfusion scintigraphy.

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

AIM: To explore portal hypertension and portosystemic 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 angioscintigraphy (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 circulation 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 inflow. 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. Abnormal LTT had PPV = 100% for CLD. 27 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 classification 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 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 portal 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 of diffuse chronic liver diseases and portal hypertension.

Radio-isotopic techniques may be useful in diagnosis and staging of chronic diffuse liver diseases. Liver angioscintigraphy (LAS) and per-rectal portal scintigraphy (PRPS) are at well discriminating portal hypertension (PHT), very early cirrhosis hemodynamic failure and compensatory arterialisation of liver perfusion. Supplied information is related to PHT, liver morphology and mesenchimal activity in liver, spleen and bone marrow. Correlation of LAS and PRPS may diagnose installing of PHT earlier than any actual morphologic imagistic method. Our experience (after more than 300 PRPS and 500 LAS) suggests that PHT and portal-cave shunts (PCS) may be classified in five functional stages. These five patterns (types) are characteristic for portal dynamics, supporting disease staging and follow-up of evolution to cirrhosis. All five dynamics may be assessed by PRPS and LAS. Scintigraphic techniques also explore portal thromboses, perfusion differences between the lobes of cirrhotic liver, betablockers effect in PHT, earliest stages of PHT, malignant tumours occurring on cirrhosis, the different characteristics of alcoholic liver comparing to viral etiology.

Liver angioscintigraphy: clinical applications.

Liver angioscintigraphy (LAS) is a radio-isotope method for the investigation of liver perfusion and its alteration in various hepatic diseases. It measures the arterial and portal venous fractions of total liver blood flow. The percentage of liver blood flow supplied by hepatic artery is estimated mathematically by the hepatic perfusion index (HPI), normally between 25 % and 40 %. The decrease of portal blood flow in liver cirrhosis is compensated ("buffer" mechanisms) by increased arterial supply, with higher HPI value. For a patient with chronic liver disease, HPI over 50% suggests arterialization of hepatic perfusion, guiding the diagnose to liver cirrhosis. Splenic curve is completing the diagnostic information of the hepatic curve. Corroborated with per rectal scintigraphy and liver SPECT, LAS offers a good hemodynamic staging of chronic inflammatory liver diseases. Malignant tumors (primitive or metastases) increase the arterial supply of the liver and decrease the portal flow, HPI being over 50% (currently 65 % - 90 %). Benign tumors do not change portal/arterial liver blood flow ratio. SPECT or non-scintigraphic morphological investigations increase the diagnostic value of LAS for primitive liver tumors. Liver cancer occurring on cirrhosis is a limitative factor for LAS. Hepatic metastases increase the arterial perfusion (and HPI value) very quickly, before their size allows morphologic imaging diagnosis. LAS is therefore an early method to diagnose liver metastases being especially used in colorectal cancer. Other clinical applications of LAS are: follow up of liver toxicity of drugs, evaluation of portal vein permeability, post surgery follow up of the liver tumor patients.