CLINICAL MEDICINE

Detailed explanation-1: -Most MRI contrast agents are chelates of the rare-earth element gadolinium and produce an increased signal (“positive contrast”) on T1-weighted images (the effect on T2-weighted images is generally negligible). Extracellular agents: These are the most commonly used.

Detailed explanation-2: -Gadolinium contrast media consist of complex molecules, arrangements of atoms held together by chemical bonds. The chemical bonds are made between a gadolinium ion and a carrier molecule (a chelating agent). A chelating agent prevents the toxicity of gadolinium while maintaining its contrast properties.

Detailed explanation-3: -They are a type of paramagnetic contrast agent, which are the primary class of MRI contrast media.

Detailed explanation-4: -GBCAs are used with medical imaging devices called MRI scanners to examine the body for problems such as cancer, infections, or bleeding. GBCAs contain gadolinium, a heavy metal.

Detailed explanation-5: -Chemistry. The gadolinium ion is useful as an MRI contrast agent because it has seven unpaired electrons, which is the greatest number of unpaired electron spins possible for an atom. Gadolinium molecules shorten the spin-lattice relaxation time (T1) of voxels in which they are present.