Short name: Mn-DPDP
This MRI contrast agent is a chelate complex of the paramagnetic metal ion manganese (Mn) and fodipir. Mn-DPDP (Teslascan) shortens the longitudinal relaxation time and is used for the T1 weighted enhancement of MR images. Mangafodipir trisodium accumulates after intravenous injection in the healthy tissue of the liver and improves the detection, localization, characterization, and evaluation of lesions of the liver, pancreas, but can also be used in cardiac MRI.
See also Hepatobiliary Chelates and Teslascan®.
The United States Food and Drug Administration (FDA) has granted marketing clearance 1997, to Nycomed Amersham's MRI contrast medium. Nycomed/Amersham, now GE Healthcare markets the product under the trade name Teslascan®.

Longitudinal relaxation rate equal to reciprocal of T1 relaxation time (R1= 1/T1).

Longitudinal relaxation rate equal to reciprocal of T2 relaxation time (R2 = 1/T2).

(T1) The spin lattice relaxation time (also called longitudinal relaxation time and T1 Time) is a spin property, whereby the value changes between different tissues. By the spin lattice relaxation process, the longitudinal magnetization Mz achieve the equilibrium value Mz0. The T1 time constant is an exponential approach toward Mz0.
The equation for the magnetization at a time t will be (if at t=0 the longitudinal magnetization is Mz0):
Mz(t) = M0+(Mz (0) - Mz0) exp(t/T1)

The basis of T1 weighted imaging is the longitudinal relaxation. A T1 weighted magnetic resonance image is created typically by using short TE and TR times.
The final image is a reflection of more than one of these pulse sequence parameters, weighted according to the type of sequence and its timing. T1 signals determine predominantly the contrast and brightness in this type of images but proton density will always contribute to the image intensity. The T1 dependence is mainly determined by the repetition time or any pre-pulses (such as in an inversion recovery pulse sequence).
Due to the larger longitudinal and transverse magnetization, fat has a higher signal and will appear bright on a T1 contrast MR image. Conversely, water has less longitudinal magnetization prior to a RF pulse, therefore less transverse magnetization after a RF pulse yielding low signal appearing dark on a T1 contrast image. Often, a paramagnetic contrast agent, a gadolinium compound, is administered, and both pre-contrast T1 weighted images and post-contrast T1 weighted images are obtained.