Imaging-based dynamic liver testing--a computerized simulation.

Abstract

BACKGROUND/AIMS: The mechanisms for maintaining liver function are complex and currently used liver function tests give limited and often nonspecific and insensitive results. The aim of the study was to demonstrate a dynamic liver test with a tomographic imaging modality as sampling method by means of a computer simulation. METHODOLOGY: A virtual three-dimensional liver model, consisting of parenchyma and bile ducts, was created using computer aided design/computer aided manufacturing software. An intravenously administered, bile excreted test substance was simulated in the model by awarding changing densities to the parenchyma and bile ducts in 12 identical sets of the model. RESULTS: Imaging-based density measurements enabled the creation of time-density curves reflecting the transport of the simulated test substance in the parenchymal mass and bile ducts. By means of quantitative analysis of the curves, parenchymal uptake and excretion and intrahepatic bile flow could be assessed independently. CONCLUSIONS: The method enables comparison of function in different liver segments and may have particular value in investigating diseases that affect the liver in a non-homogeneous fashion, for example primary sclerosing cholangitis. Imaging sampling can theoretically be applied with any tomographic imaging technique for which a suitable test substrate exists, including computed tomography, magnetic resonance imaging or single photon emission tomography.