<unk>  (trade names Artirem, Dotarem) is a macrocycle-structured gadolinium-based MRI contrast agent. It consists of the organic acid DOTA as a chelating agent, and gadolinium (Gd3+), and is used in form of the meglumine salt. The drug is approved and used in a number of countries worldwide. It is used to assist imaging of blood vessels and of inflamed or diseased tissue where the blood vessels become 'leaky'. It is often used when viewing intracranial lesions with abnormal vascularity or abnormalities in the blood–brain barrier.  Its paramagnetic property reduces the T1 relaxation time (and to some extent the T2 and T2* relaxation times) in NMR, which is the source of its clinical utility.
Gadoteric acid
Edetate disodium
Indigotindisulfonate
Gadoxetic acid
Acetrizoic acid
Poractant Alfa
Meticrane
Ioxaglic acid