Paramagnetism. Gadolinium is used as a MRI contrast agent. At the proper concentration, gadolinium contrast agents cause preferential T1 relaxation enhancement, causing an increase in signal on T1-weighted images. At high concentrations, as is sometimes seen in the urinary bladder, loss of signal is seen instead,...How paramagnetic is gadolinium in MRI?
In general, paramagnetic effects are small ( magnetic susceptibility of the order of 10 -3 to 10 -5 ). In MRI, gadolinium (Gd) one of these paramagnetic materials is used as a contrast agent.What is the effect of paramagnetic contrast on the relaxation time?
The paramagnetic contrast agents generate a magnetic field 1000 times stronger than water protons. The interaction between the contrast agent and the water proton is exactly the same as the corresponding interactions with other molecules except that the magnitude of their magnetic interaction has a much greater effect on the relaxation time.What are the types of paramagnetic contrast agents?
The primary class of paramagnetic contrast agent is gadolinium-based contrast agents. Others include ferric ammonium citrate and manganese-based contrast agents.