What effect does gadolinium have on T1 and T2 relaxation times in MRI?

Gadolinium is a contrast agent commonly used in MRI to enhance the quality of the images obtained. It significantly affects the relaxation times of hydrogen protons, which are critical for generating MRI signals.

When gadolinium is introduced into the body, it shortens T1 relaxation times. This occurs because gadolinium has a high magnetic moment and facilitates the transfer of energy to the surrounding protons, allowing them to return to their equilibrium state more quickly. Consequently, tissues with gadolinium present will exhibit brighter signals on T1-weighted images due to this shortening effect.

In addition to its impact on T1, gadolinium also influences T2 relaxation times. While the primary effect of gadolinium is to shorten T1, it should also be noted that it can have a diminishing effect on T2 relaxation times in certain contexts, which could lead to an overall shortening of T2 as well in some tissues. This is primarily due to the paramagnetic properties of gadolinium, which can cause intravoxel dephasing due to field inhomogeneities, leading to a faster decay of the transverse magnetization.

Therefore, the assertion that both T1 and T2 relaxation times are shortened when gadolinium is introduced to a