MRT hand with contrast medium
A contrast medium is a substance that has strong radiation-absorbing properties so that an organ or body area can be better represented by an artificially created density difference. The use of a contrast medium increases the image contrast and improves the visualization of pathological blood circulation and bleeding in the hand. A contrast medium helps to better distinguish between different types of tissue.
Without contrast medium, muscles and blood vessels, for example, are shown in similar shades of grey. By using contrast medium, areas with blood circulation appear brighter on the MRI image of the hand. Pathological processes can thus be better and more reliably detected.
Tumors in the area of the hand can also be better visualized with contrast medium, since tumor tissue often leads to the formation of new blood vessels, so that contrast medium accumulates in tumors. For example, a usually harmless cyst can be distinguished from a tumor. It is also noticeable when less contrast medium accumulates in a tissue because the blood supply is poorer, as is the case in scar tissue, for example.
Before a contrast medium is used, the kidney values (creatinine, GFR) must be checked, as the contrast medium is excreted again via the kidneys and accumulation/enrichment of the contrast medium is dangerous for the body. The control of these laboratory parameters is routinely performed in patients over fifty years of age and patients with known kidney disease. Prior to the examination, the patient must have had an empty stomach for three hours, i.e. not have consumed any food or drink.
A contrast medium should be used, especially for the detection of inflammatory diseases, because without contrast medium, inflammatory processes in joints and tendons cannot be correctly visualized and may be overlooked. For joint imaging, as is usually required on the hand, MultiHance (gadolinium BOPTA) is used as a contrast medium, which is generally well tolerated. Gadolinium is generally the standard contrast medium for MRI examinations.
For the examination of joints, the contrast agent can be injected directly into the joint in question or administered through a vein (as is usually the case). Afterwards, the joint should be moved well before the MRI measurement so that the contrast medium can spread well. Very rarely, the administration of a contrast medium causes side effects.
Sometimes local, usually harmless side effects occur at the injection site of the vein access. Since MRI contrast media do not contain iodine, as is often the case with X-ray contrast media, side effects occur much less frequently. Allergic reactions caused by the administration of an MRI contrast medium are extremely rare. Often it is only a reddening of the skin. The incidence of allergic side effects affecting the body’s circulation and respiration is less than 0.004%.
