(Mn-DPDP) This agent, mangafodipir trisodium, is a hepatocyte specific MRI contrast agent. Manganese is very toxic, so it has to be chelated and put in the form of a vitamin B6 analog, which is taken up by normal hepatocytes to some extent.
Teslascan® was developed in the early 1980's, went through clinical trials in the early 1990's, and was approved in 1997. One problem with assessing the efficacy of this agent is the fact that the phase III trials finished in the early 1990's, and the techniques used for MR today are very different from the techniques used almost a decade ago.
This contrast agent shortens the T1 relaxation time. On T1 weighted pictures it makes a normal liver look brighter. Since metastases, for example, do not generally take up this agent, the contrast between the enhancing liver and the non-enhancing lesions will increase on T1 weighted pictures. It does not have much effect on T2 weighted images.

Tumor specific MRI contrast agents are in development to provide better delineation and progression information for various tumors. Clinical oncology has a need for contrast agents that can identify tumors and metastases at a size of 100,000 cells rather than 1,000,000,000 cells. This level of sensitivity requires excellent tumor targeting of imaging agents and a high MRI signal.
Tumor specific agents accumulate at pathological tissues by passive or active targeting mechanisms. Passive targeting agents use e.g., the natural defense mechanisms in which phagocytic cells remove foreign particles from the body. Active targeting is based on a ligand-directed, site-specific accumulation of contrast agents. The availability of macromolecular contrast agents such as feruglose and ultrasmall superparamagnetic iron oxide (USPIO), which permit the assessment of tissue permeability, may also improve the detection of tumor grade, tumor type, and response to drugs that target angiogenesis.

See also Monoclonal Antibodies, Metalloporphyrins, Nitroxides and Ferrioxamine.

(USPIO) The class of the ultrasmall superparamagnetic iron oxide includes several chemically and pharmacologically very distinct materials, which may or may not be interchangeable for a specific use. Some ultrasmall SPIO particles (median diameter less than 50nm) are used as MRI contrast agents (Sinerem®, Combidex®), e.g. to differentiate metastatic from inflammatory lymph nodes. USPIO shows also potential for providing important information about angiogenesis in cancer tumors and could possibly complement MRI helping physicians to identify dangerous arteriosclerosis plaques.
Because of the disadvantageous large T2*//T1 ratio, USPIO compounds are less suitable for arterial bolus contrast enhanced magnetic resonance angiography than gadolinium complexes. The tiny ultrasmall superparamagnetic iron oxides do not accumulate in the RES system as fast as larger particles, which results in a long plasma half-life. USPIO particles, with a small median diameter (less than 10 nm), will accumulate in lymph nodes after an intravenous injection by e.g. direct transcapillary passage through endothelial venules. Once within the nodal parenchyma, phagocytic cells of the mononuclear phagocyte system take up the particles.
As a second way, USPIOs are subsequently taken up from then interstitium by lymphatic vessels and transported to regional lymph nodes. A lymph node with normal phagocytic function takes up a considerable amount and shows a reduction of the signal intensity caused by T2 shortening effects and magnetic susceptibility. Caused by the small uptake of the USPIOs in metastatic lymph nodes, they appear with less signal reduction, and permit the differentiation of healthy lymph nodes from normal-sized, metastatic nodes.

See also Superparamagnetic Contrast Agents, Superparamagnetic Iron Oxide, Very Small Superparamagnetic Iron Oxide Particles, Blood Pool Agents, Intracellular Contrast Agents.

The company changed its name from Advanced Magnetics, Inc. to AMAG Pharmaceuticals, Inc. in July 2007.
AMAG Pharmaceuticals, Inc., a biopharmaceutical company, developed and manufactured organ-specific diagnostic contrast agents that provide clearer images during magnetic resonance imaging (MRI) tests used to detect tumors and other abnormalities.
The company had two MRI related products on the market: Feridex I.V. (for the diagnosis of liver lesions) and GastroMARK (used for bowel and abdominal MR imaging). In November 2008, AMAG Pharmaceuticals, Inc. decided to discontinue the manufacturing of Feridex. The development of Combidex as a contrast agent for lymph disease has also been stopped.
The Company has now two commercial products: Feraheme® and GastroMARK®. Feraheme® is the trade name of Ferumoxytol (formerly Code 7228) and is indicated for the treatment of iron deficiency anemia. Feraheme® is also being developed as a diagnostic agent for vascular-enhanced magnetic resonance imaging (MRI) to assess peripheral arterial disease.

MRI Contrast Agents:

This superparamagnetic oral contrast agent consists of large iron oxide particles, coated with insoluble material. Abdoscan® particles have a mean diameter no less than 300 nm. Gastrointestinal superparamagnetic contrast agents are used for negative bowel enhancement.

Abdoscan® was approved in Europe but was taken off the market in 2000, and all sales stopped by the end of 2002.