Iodinated Contrast Media: from Non-Specific to Blood-Pool Agents

Abstract

In 1998, the commercial introduction of multislice computed tomography made X-ray functional imaging possible. Specific contrast agents that could remain within the intravascular compartment for a substantially longer time than conventional nonspecific agents may allow the quantification of local blood volume, tissue perfusion and permeability and thus the characterization of several types of lesions. We describe a new series of monodisperse, macromolecular iodinated contrast agents. The synthesis, analysis and pharmacokinetics of these molecules are presented. Their pharmacokinetic profiles are consistent with those of blood-pool agents, of either the rapid- or slow-clearance categories. Their diffusion through the endothelium was found to be low in vitro, thus confirming early confinement of these macromolecules, unlike nonspecific contrast agents. Preclinical safety data (including renal and immunological tolerability) are promising and should allow further evaluation of these compounds to be carried out.