(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.

(VSOP = very small superparamagnetic iron oxide particles) This new class of contrast agents with smaller particle size than SPIO offers advantages for MR angiography. SPIO particles are usually coated with an organic polymer such as dextran, carboxydextran or polyethylene glycol, which limits the minimal overall particle size that can be obtained. VSOP-C184 consists of an aqueous solution of superparamagnetic iron oxide particles with a citrate coating and the overall particle size of 4-8 nm.
Short name: VSOP-C184, central moiety: Fe, concentration: 29 g Fe/l, relaxivity: R1=20.1, R2=37.1, B0=0.94 T.