Relaxivity of Paramagnetic Complexes of Manganese and Gadolinium

The relaxivities of aqueous solutions of the manganese complexes Mn-CDTA, Mn-DTPA, and Mn-EDTA were compared with that of the gadolinium complex Gd-DTPA. Relaxivities R1 and R2 of Mn-CDTA solutions were slightly greater than those of Gd-DTPA. The lowest relaxivities were seen for Mn-DTPA, while Mn-EDTA occupied an intermediate position between Mc-CTDA and Mn-DTPA.