Magnetic Nanoparticles for MR Imaging

Abstract

The combination of a nonmaterial, magnetic nanoparticles, with magnetic resonance imaging, is yielding major advances in diverse areas of biology and medicine. This review will present a short history of iron oxide based nanoparticles, and review important new developments in the fields of magnetic nanoparticles and MRI. Magnetic nanoparticles are currently used in approved MRI contrast agents for imaging hepatic metastases and show considerable potential in clinical testing for imaging nodal metastases. New applications of magnetic nanoparticles include (i) ex-vivo labeling of cells with nanoparticles, followed by MR imaging in vivo, (ii) magnetic nanoparticles as biosensors termed magnetic relaxation switches, to measure a wide range of analytes in vitro, (iii) magneto/optical nanoparticles providing a fluorescent signal in addition to their magnetic character and (iv) biomolecule targeted magnetic nanoparticles for the imaging of specific molecular targets by MRI. This review will cover each of these diverse developments.