Iron-EHPG as an hepatobiliary MR contrast agent: initial imaging and biodistribution studies.
The paramagnetic metal complex iron(III) ethylenebis-(2-hydroxyphenylglycine) [Fe(EHPG)-] is an effective hepatobiliary contrast agent for liver enhancement in magnetic resonance (MR) imaging. The intravenous administration of 0.2 mmol/kg of Fe(EHPG)- to rats yields a 200% increase in the signal intensity of the liver when using a T1-weighted inversion recovery pulse sequence on a 1.4 T imaging system. Biodistribution studies in rats and a rabbit, along with imaging studies in a dog at 0.6 T, confirm that the complex has significant hepatocellular uptake and appears to be excreted unaltered into the bile. Control experiments with a different iron complex, iron(III) diethylenetriaminepentaacetic acid, reveal little hepatic affinity and poor enhancement capability due to its extracellular distribution. This initial evaluation of Fe(EHPG)- demonstrates that paramagnetic metal complexes with hepatobiliary specificity are well suited for enhancement of normal liver parenchyma and may increase the sensitivity of MR in the detection of liver disease.
D000818:Animals; D001659:Biliary Tract / Q000033:anatomy & histology*; D003287:Contrast Media; D004285:Dogs; D005029:Ethylenediamines; D005260:Female; D005290:Ferric Compounds; D007502:Iron Chelating Agents; D008099:Liver / Q000033:anatomy & histology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D004369:Pentetic Acid; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
D003287:Contrast Media; D005029:Ethylenediamines; D005290:Ferric Compounds; D007502:Iron Chelating Agents; C011813:ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid); D004369:Pentetic Acid