Science to practice: how will myocardial inflammation be imaged with MR imaging?

The elegant study by Naresh and colleagues (1) synthesizes many of the best aspects of molecular magnetic resonance(MR) imaging: Quantitative serial imaging of a well-defined molecular process is performed in vivo, and its results are correlated with sensitive measures of left ventricular function. The technique described adds a valuable tool to the molecular imaging armamentarium. How, then, will myocardial inflammation be imaged with MR imaging?The only clinical experience to date has been with iron oxide nanoparticles (2,3). Their excellent sensitivity, dynamic range, and safety record make them a highly appealing choice. It will be critical, however, for any iron oxide nanoparticle that is used clinically to be well studied and validated in animal models of the disease before it is used in humans. A “group effect” cannot be assumed, even in the case of fairly similar iron oxide nanoparticles. The use of MR imaging–detectable liposomes appears promising,and initial clinical studies with fluorine-containing liposomes are likely to begin shortly. The clinical use of gadolinium-labeled liposomes appears further away, and the approach described by Naresh and colleagues is thus likely to remain confined to preclinical investigation for the foreseeable future. The development of novel anti-inflammatory therapies, however, will require robust imaging tools to shepherd these agents through preclinical studies and into the clinical arena. The approach described by Naresh et al adds a valuable tool to the preclinical molecular imaging armamentarium.