Imagerie par Résonance Magnétique (IRM) fonctionnelle de l'ischémic hépatique chez le Lapin. Contribution d'un agent de contraste particulaire (AMI-25)

A functional approach of the rabbit portal ischemia was performed on five New Zealand rabbits using magnetic-resonance (MR) imaging and an MR-specific contrast agent for the liver. The hepatic vascularization and the functionality of the phagocytosis cells were both studied with a single low dose of a unique contrast agent—superparamagnetic iron oxide particles (SPIOs). After a rapid i.v. injection of SPIOs, functional vessels and normally perfused liver parenchyma appeared with positive signal enhancement, whereas the ischemic area remained dark (cold spot). After the intravascular time period, the well-known negative enhancement induced by these particles on normal parenchyma was observed, with the difference of the ischemic liver, and could be related to the uptake of SPIOs by functional Kuppfer cells.