Resovist® is an organ-specific MRI contrast agent, used for the detection and characterization of especially small focal liver lesions.
Resovist® consists of superparamagnetic iron oxide (SPIO) nanoparticles coated with carboxydextran, which are accumulated by phagocytosis in cells of the reticuloendothelial system (RES) of the liver. The uptake of Resovist® Injection in the reticuloendothelial cells results in a decrease of the signal intensity of normal liver parenchyma on both T2- and T1 weighted images.
Most malignant liver tumors do not contain RES cells and therefore do not uptake the iron particles. The resulting imaging effect is an improved contrast between the tumor (bright) and the surrounding tissue (dark).
Resovist® can be injected as an intravenous bolus, which allows immediate imaging of the liver and reduces the overall examination time. A dynamic imaging strategy after bolus injection supports to characterize lesions. In comprehensive clinical trials, it demonstrated an excellent safety profile.
In 2001, Resovist® was approved for the European market.

See also Superparamagnetic Iron Oxide.

Resovist® competed with Primovist™, the other liver imaging agent of Bayer Schering Pharma AG. Due to this reason, the production of Resovist® has been abandoned in 2009.

Time-dependent electromagnetic fields are significantly attenuated by conducting media (including the human body); the skin depth gives a measure of the average depth of penetration of the RF field. A high power frequency tunable RF source can be rapidly switched on and off. This produces a large RF field perpendicular to the magnetic field. This RF field is focused by the body coil. The RF source and coils must be tunable in both frequency and impedance to 'match the impedance' of the patient's body.

The skin depth may be a limiting factor in MR imaging at very high frequencies (high magnetic fields). The skin depth also affects the Q of the coils.

Pharmaceutical products in transdermal skin patches may cause burns due to the absorption of RF energy.

Such patches must be removed prior to MR examinations.

(SFDA) The State Food and Drug Administration of the People's Republic of China was founded in November 2003 and is directly under the State Council. The State Food and Drug Administration is in charge of comprehensive supervision on the safety management of food, health food and cosmetics and is the competent authority of drug regulation. For drug or medical device registration please see the SFDA's Regulatory Guide.
The agency is China's equivalent of the US Food and Drug Administration.

Tattoos with metallic or ferromagnetic color ingredients can distort MR images. Skin irritations or burns caused by heating of the metallic particles due to the radio frequency pulse are also possible, but rare.

Patients should be informed about the possible risk, and scanning should be stopped immediately if they feel heat. Metallic make-up can even be pulled into the eye by magnetic forces and should be removed previous to the MRI scan.