The Characterization and Imaging Behavior of a New Developed Paramagnetic Contrast Agent NMG2[Gd(TTDA-BOM)]

[Gd(TTDA-BOM)]^2- is a newly developed paramagnetic contrast agent. The ligand, TTDA-BOM, bears a benzyloxymethyl group so that the lipophilicity is increased. The water exchange rate for [Gd(TTDA-BOM)]^2- is significantly higher than that of [Gd(DTPA)]^2- and [Gd(BOPTA)]^2-. In addition, the bound relaxivity of this Gd (III) complex has a remarkably high value with HSA. Therefore, it has potential to be used as a blood pool contrast agent for MRI. The aim of this study is to investigate the characterization and imaging behavior of NMG₂[Gd(TTDA-BOM)] in normal rat livers and hearts using a 3T high field whole-body MR scanner. The high field MR scanner is expected to have a higher signal to noise ratio. The relaxivities r₁ and r₂ for [Gd(TTDA-BOM)]^2- at 3T are 5.97 mM^-1 s^-1 and 7.99 mM^-1 s^-1 respectively, which are higher than those for [Gd(DTPA)]² (r₁=4.64 mM^-1 s^-1 and r₂=5.08 mM^-1 s^-1). The dynamic MRI studies show that there is marked enhancement in livers and hearts right after the bolus injection and the enhancement ratios keep high until two hours. In conclusion, [Gd(TTDA-BOM)]^2- might have a good potential in both cardiovascular and hepatobiliary applications