From Toshiba America Medical Systems Inc.;
OPART™ is a 0.35 T superconducting open MR system featuring cryogenless operation. Superconducting speed and performance are combined with the patient access advantages of open MRI design for unmatched clinical versatility. OPART™ features innovative technologies such as digital RF, high speed gradients and optimized RF coils, which support advanced MRI applications.

Nanoparticles may be utilize as a new class of uniform, biodegradable and non-toxic superparamagnetic contrast agents (Fe3O4). The preparation process of these particles is simple, does not involve any toxic material and the yield is close to 100%. The particles are usually of varying sizes from several to several hundred nanometer. They are irregular in shape and highly light-absorbing. They have no magnetic hysteresis at ambient temperatures, which is characteristic of superparamagnetic materials. Each magnetic nanoparticle is composed of a very thin organic nucleus (5-10%) and a thick shell of magnetite.
Different techniques were established for coating these magnetite nanoparticles with several functional and biocompatible polymers. Both the coating and the magnetite production processes are controllable, so that it is possible to prepare particles with a specific size of each particle component as well as particles coated with protein ligands for tissue specific imaging applications.

Short name: MION, central moiety: Fe3+/Fe2+, relaxivity: r1=3.7, r2=6.5, B0=0.47T
MIONs are under development (preclin.) as contrast agents (taken up by the RES) for MR angiography, MR lymphography, tumor detection and detection of infarctioned tissue. Also called monodisperse iron oxide nanoparticles or nanocompounds.

Short name: PION, generic name: Polycrystalline iron oxide nanoparticles, central moiety: Fe2+/Fe3+, relaxivity: T2*enhanced, r2//r1=4.4, r2//r1=7
A substance under development (preclin.) as an RES-directed MRI contrast agent (larger particles = DDM 128, PION-ASF) for MR lymphography and the detection of liver lesions.

Molecular Imaging is a new diagnostic discipline to visualize biological processes.
Molecular magnetic resonance imaging (mMRI) offers the potential to image tissues at the cellular and subcellular level. Targeted MR contrast agents enhance the diagnostic specificity and range of molecular magnetic resonance imaging.
Other modalities that can be used for noninvasive molecular imaging:

See also Nanoparticle, Monocrystalline Iron Oxide Nanoparticle, Polycrystalline Iron Oxide Nanoparticles, Liposomes, Monoclonal Antibodies, Bimodal Imaging, Tumor Specific Agents, and Intracellular Contrast Agents.