MULTINUCLEAR MR CHARACTERIZATION OF A NEW HEPATOBILIARY CONTRAST AGENT - PRELIMINARY-RESULTS

Purpose. The aim of this work was to characterize the hepatobiliary co ntrast agent Gd-EOB-DTPA in various media: water solution, protein sol ution, phosphorylated metabolite solution, and excised and perfused li ver tissue. Material and Methods: Different NMR techniques were used: analyses of H-l NMRD profiles, H-2 NMR relaxation rates, O-17 relaxati on rates and chemical shifts, and P-31 relaxation rates and peak area. Results: The higher proton relaxivity of Gd-EOB DTPA in water as comp ared to that of Gd-DTPA is due to a smaller distance r and to a longer tau(R). The kinetic stability of the former compound in ATP solution is higher and it forms noncovalent bonds with human serum albumin. Int ernalization of the contrast agent by the hepatocytes does not impair the ATP metabolism of the cells but induces relaxation effects on the intracellular metabolites of the liver. Conclusion: Multinuclear MR st udies allow the extensive characterization of MR contrast agents in in vitro and ex vivo model systems.