Quantitative Evaluation of Liver Function within MR Imaging

Gadoxetic Acid Uptake Rate as a Measure of Global and Regional Liver Function as Compared With Indocyanine Green Retention, Albumin-Bilirubin Score, and Portal Venous Perfusion

“…Other quantitative or semi-quantitative methods have been used to derive metrics from dynamic gadoxetic acid enhanced MRI, e.g., hepatic extraction fraction (HEF), liver to spleen ratio, and hepatocyte transport indices. HEF and liver to spleen ratio, although showing promise in prediction of global liver function in patients with good liver function [27][28][29]33,34 , do not differentiate contrast uptake by parenchyma from contrast in blood plasma, and the latter assumes conformity to flow enhancement in the spleen. While semi-quantitative measures benefit from simplicity, they are more scanner and acquisition dependent measures 35 .…”

Compartment model analysis of intravenous contrast‐enhanced dynamic computed tomography in hepatic hemodynamics: A validation study using intra‐arterial contrast‐enhanced computed tomography

“…Our results showed that an appropriate evaluation of arterial and portal venous hepatic flows was possible when the upper limit of k 2 was set neither too low nor too high. The k 2 represents venous out flow during tissue perfusion; therefore, a high k 2 correlates with rapid wash out of the contrast medium, resulting in a steep decrease in the TCC between early‐ and late‐phase imaging . Our results showed that the mean correlation coefficient between k 1a and nCTHA was relatively good (higher than 0.4) regardless of the k 2 limit.…”

“…The movement of the contrast medium between pharmacokinetic compartments in the liver can be expressed using quantitative parameters, such as the arterial inflow velocity constant ( k 1a ), portal venous inflow velocity constant ( k 1p ), and venous outflow constant ( k 2 ), in this model. Because the CMA in liver perfusion is more complex than the 1‐in‐1‐out‐compartment model used in other non‐hepatic tissues, the parameters should be determined by non‐linear procedures such as curve fitting of the time‐density curve (TDC) using the non‐linear least square method . Appropriate limits for perfusion parameters should be determined in these procedures to avoid a local minima problem that could cause the computation to stop at an unreasonable answer because of false‐best curve fitting .…”

GAN and dual‐input two‐compartment model‐based training of a neural network for robust quantification of contrast uptake rate in gadoxetic acid‐enhanced MRI

“…Gadoxetic acid provides utility as a hepatobiliary contrast, allowing interrogation of the uptake of contrast into the hepatocytes as well as liver perfusion parameters. Various pharmacokinetic parameters have been used as a measure of regional liver function with gadoxetic acid uptake rate being among the most direct due to its correspondence with the number of functioning hepatocytes, making it a reasonable quantitative measure of regional liver function . Quantitation of regional liver function is important in functional avoidance therapy, where radiation therapy is optimized to spare highly functional regions of the liver .…”