The definition of a scan is to form an image or an electronic representation. The MRI scan uses magnetic resonance principles to produce extremely detailed pictures of the body tissue without the need for X-ray exposure or other damaging forms of radiation.
MRI scans show structures of the different tissues in the body. The tissue that has the least hydrogen atoms (e.g., bones) appears dark, while the tissue with many hydrogen atoms (e.g., fat) looks bright. The MRI pictures of the brain show details and abnormal structures (brain MRI), for example, tumors, multiple sclerosis lesions, bleedings, or brain tissue that has suffered lack of oxygen after a stroke. A cardiac MRI scan demonstrates the heart as well as blood vessels (cardiovascular imaging) and is used to detect heart defects with e.g., changes in the thickness and infarctions of the muscles around the heart. With MRI scans, nearly all kind of body parts can be tested, for example the joints like knee and shoulder, lumbar, thoracic and cervical spine, the pelvis including fetal MRI, and the soft parts of the body such as the liver, kidneys, and spleen. The MRI procedure includes three to nine imaging sequences and may take up to one hour.

See also Lumbar Spine MRI, MRI Safety and Open MRI.

Nitroxide radicals (or nitroxyl spin labels) are stable organic compounds with theoretical potential for use as a paramagnetic MRI contrast agent. Similar to gadolinium they have an unpaired electron, a property that provides enhancement in T1 based MRI, and a comparable pharmacokinetic. Depending on their structure and chemical bonding, different nitroxides formula may have the potential for use as cardiovascular imaging agents, to enhance the MR imaging on joints (e.g., dendrimer-linked nitroxides have a strong affinity for cartilage), to evaluate brain tumors and infarction, and as a contrast enhancement agent of body/abdominal NMR imaging. Nitroxides are rapidly enzymatically reduced in tissues to products that do not enhance the NMR signal, which can be a problem for MR imaging. In animal experiments with EPRI (electron paramagnetic resonance imaging), tissue redox studies show differences between tumors and normal tissues, which reflect their respective redox status consistent with the reduction/clearance of nitroxides.

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.'

[This entry is marked for removal.]

(July 20, 2009 - EPIX Pharmaceuticals, Inc. announced today that, in light of the company's lack of capital and inability to obtain additional financing or consummate a strategic transaction, it has entered into an Assignment for the Benefit of Creditors, effective immediately, in accordance with Massachusetts law).
EPIX has been a specialty pharmaceutical firm developing targeted contrast agents to improve the capability of MRI as a diagnostic tool for a variety of diseases. Gadofosveset trisodium (formerly MS-325, Vasovistâ„¢, now ABLAVARtâ„¢), is an injectable intravascular contrast agents designed for multiple vascular imaging applications, including peripheral vascular disease and coronary artery disease. EPIX conducted a pivotal Phase III trial for the detection of peripheral vascular disease, as well as a Phase II feasibility trial for coronary artery disease diagnosis.
To ensure rapid development and adoption of gadofosveset trisodium into clinical practice upon regulatory approval, EPIX pursued an aggressive product development plan and commercialization strategy. The Company established an exclusive, worldwide sales and marketing agreement with Bayer Schering Pharma AG. EPIX also established corporate collaborations with GE Healthcare, Philips Medical Systems and Siemens Medical Systems, the three leading MRI manufacturers, which together account for approximately 80 percent of the MRI machines installed worldwide.
EPIX had other MRI contrast agents under development, most significantly a novel prototype blood clot agent (EP-2104R). Potential clinical applications for this type of agent include detection of deep venous thrombosis, pulmonary embolism and blood clots in the coronary and carotid arteries. Currently, there is no high resolution imaging technique to directly visualize blood clots in patients with suspected cardiovascular disease.

From Philips Medical Systems;
The clinical capabilities of MR will further expand. Inside and out, the Achieva is a friendly, open system designed for optimal patient comfort and maximized workflow with high functionality. The Achieva 1.5T can be upgraded to Achieva I/T, with three configurations optimized for MR guided interventions and therapy: