Equis ISSN 2398-2977

Liver: scintigraphy

Synonym(s): Hepatic nuclear medicine studies

Contributor(s): Russel Malton, Rachel Murray

Introduction

  • In animals, hepatic and hepatobiliary scintigraphy originally provided information on hepatic and biliary morphology and biliary kinetics.
  • Hepatic scintigraphy studies reported in the horse to date are scant. 
  • Studies include:
    • A morphologic study comparing 99mTc-iminodiacetic acid derivatives.
    • A study using 99mTc-disofenin to determine normal morphology of the liver and biliary tract of the adult horse, and to determine the effects of feeding on biliary kinetics.
  • Quantification of hepatocyte function requires measurement of the efficiency of uptake of a radiopharmaceutical which is taken up exclusively by the liver and is excreted into the bile with minimal backflow into the blood. 99mTc-iminodiacetic acid derivatives fulfil these requirements. The higher molecular weight derivatives undergo less competitive inhibition in the presence of  elevated serum bilirubin levels resulting in less compensatory renal excretion.
  • This measure of hepatic extraction efficiency is termed the hepatic extraction fraction  (HEF)and is defined as the proportion of the radiopharmaceutical removed from the blood on each circulatory pass through the liver.
  • Both plasma clearance of 99mTc-mebrofenin and scintigraphically derived heart time-activity curves have the potential in the horse to provide valuable information on hepatic function; however, they must be validated before they are recommend for clinical application.
  • Validation will require multiple studies of both normal horses and horses with known hepatic disease, documented with histopathological information from biopsy material and where possible necropsy.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Daniel G B, DeNovo R, Bahr A et al (2001) Evaluation of heart time-activity curves as a predictor of hepatic extraction of 99mTc-mebrofenin in dogs. Vet Radiol 42 (2), 162-168 PubMed.
  • Matwichuk C L, Daniel G B, DeNovo R C et al (2000) Evaluation of plasma time-activity curves of technetium-99m-mebrofenin for measurement of hepatic function in dogs. Vet Radiol 41 (1), 78-84 PubMed.
  • Hornof W J, Baker D G (1986) Biliary kinetics of horses as determined by quantitative nuclear scintigraphy. Vet Radiol 27 (3), 85-88 VetMedResource.
  • Theodorakis M C, Bermudez A J, Manning J P et al (1982) Liver scintigraphy in ponies. Am J Vet Res 43 (9), 1561-1565 PubMed.

Other sources of information

  • Daniel G B, Berry C B, Newell S (1996)Hepatic Scintigraphy.In:Handbook of Veterinary Nuclear Medicine.Eds: Berry C B & Daniel G B. North Carolina State University, Raleigh, NC, USA. pp 85-93.


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