Small particles of ferrite are used as superparamagnetic contrast medium in MR imaging (appearing predominantly dark on MRI). These agents exhibit strong T1 relaxation properties, and due to susceptibility differences to their surroundings also produce a strongly varying local magnetic field, which enhances T2 relaxation to darken the contrast media containing structures.
Superparamagnetic contrast agents are also known by the abbreviation SPIO's (small particle iron oxide or superparamagnetic iron oxide) and USPIO's (ultrasmall particle iron oxide or ultrasmall superparamagnetic iron oxide).
Two types of USPIO will be available on the market as blood pool agents, while SPIO's have been used as darkening contrast agents for liver imaging. As particulate matter they are taken up by the RES. Very small particles of less than 300 nanometers also remain intravascular for a prolonged period of time and thus can serve as blood pool agents.

See also the related poll result: 'The development of contrast agents in MRI is'

Short name: SHU 555 C, preliminary trade name: Supravistâ„¢
An ultrasmall superparamagnetic iron oxide under development as a positive enhancing blood pool agent (MRI contrast agent phase III, Bayer Schering Pharma AG). Supravist™ can be administered as an iv. bolus up to doses of 80 μmol/kg.

See also Ultrasmall Superparamagnetic Iron Oxide and Blood Pool Agents.

An ultrafast gradient echo pulse sequence with data acquisition after an initial 180° (similar to IR) preparation pulse for contrast enhancement.
See Fast Low Angle Shot and Ultrafast Gradient Echo Sequence.

From Toshiba America Medical Systems Inc.;
With its high-field strength, the Vantageâ„¢ delivers the clinical capabilities and image quality expected by cardiologists, while simultaneously offering patients a more comfortable and non-invasive option, said Dane Peshe, director, MRI Business Unit, Toshiba America Medical Systems. Vantageâ„¢ supports a full complement of cardiovascular imaging studies, ranging from stroke evaluation to peripheral vascular imaging. Additionally, the ultra short bore design offers patients a greater feeling of openness that reduces claustrophobic sensations, while Toshiba's exclusive, patented Pianissimoâ„¢ technology reduces scan noise by as much as 90 percent for a more pleasant experience.'

California-based research and development company. Alliance has several patents regarding 'microbubble' compositions such as Imagent® that are intended to enhance ultrasound imaging and Imagent GI as a gastrointestinal MRI contrast agent. Another product is Oxygent™, a synthetic 'blood substitute'.

MRI Contrast Agents:

• Imagent GI