Abstract: Three aromatic DTPA-bis(amide) gadolinium complexes have been investigated for use as hepatobiliary contrast agents for magnetic resonance imaging. The lipophilicity of the complexes was determined by means of octanol-buffer partition coefficient. The measured and theoretical lipophilicity exhibited good correlation. Protein binding studies show that the more lipophilic complex has higher BSA binding affinity. T₁-weighted spin-echo images of rabbits demonstrated hepatobiliary specific uptake and excretion could also be achieved by adding aromatic rings to the molecule of a paramagnetic complex and were sensitive to the substituents on the aromatic rings.

Key words: Magnetic resonance imaging, Aromatic DTPA-bis (amide), Hepatobiliary contrast agents, Gadolinium