# Pharmacokinetic modeling of hepatospecific MRI contrast agent flux in large animal models by dynamic contrast-enhanced MRI

## TL;DR

This study explores using dogs and pigs as models to study liver contrast agent behavior with MRI, showing promising results for translational research.

## Contribution

The study demonstrates the feasibility of using large animal models for pharmacokinetic MRI analysis of hepatospecific contrast agents.

## Key findings

- Canine Gd-EOB-DTPA pharmacokinetic values closely match human values.
- The single-input model showed higher uptake rates for hepatospecific agents.
- The dual-input model effectively captured contrast dynamics in both dogs and pigs.

## Abstract

Evaluate the feasibility of using dogs and a pig as translational models for assessing hepatic flux of hepatospecific gadolinium-based contrast agents using dynamic contrast-enhanced MRI (DCE-MRI).

DCE-MRI was performed with hepatospecific agents, gadoxetate disodium (Gd-EOB-DTPA) and gadobenate dimeglumine (Gd-BOPTA), and non-hepatospecific agents. Two validated pharmacokinetic models were applied: a single-input reference region model and a dual-input model using arterial and venous blood signals.

In dogs, hepatic enhancement rose rapidly and plateaued after Gd-EOB-DTPA administration, with minimal decline over an hour. In the pig, both hepatospecific agents showed a rapid rise, blunt peak, and gradual decline. The single-input model revealed significantly higher uptake rates for hepatospecific agents, confirming its sensitivity to hepatocyte uptake. The dual-input model effectively distinguished contrast agent dynamics in dogs and showed promise in the pig.

In this feasibility study, canine Gd-EOB-DTPA pharmacokinetic values closely mirrored those observed in humans. These results establish baseline model parameters in a large-animal setting and support further, more comprehensive investigations into their translational potential for assessing hepatic function using DCE-MRI.