Dynamic Contrast-Enhanced Magnetic Resonance Angiography of Gd-TTDA-BOM and Gd-DTPA at 3T in a Normal Rat Model

Gd-TTDA-BOM is designed to be a paramagnetic contrast agent for magnetic resonance imaging (MRI). The ligand TTDA-BOM includes a benzyloxymethyl group to raise the lipophilicity. It is known that Gd-TTDA-BOM has faster water exchange rate and higher reorientational time than Gd-DTPA. It also has high bound relaxivity with human serum albumin (HSA). This study first evaluated the relaxivity values of Gd-TTDA-BOM and Gd-DTPA solutions with 4.5% HSA and then investigated the signal enhancement of dynamic contrast-enhanced magnetic resonance angiography after Gd-TTDA-BOM or Gd-DTPA bolus injection in a normal rat model. A 3T whole-body MR scanner providing higher signal to noise ratios (SNR) than 1.5T was used. The results showed that Gd-TTDA-BOM with HSA had higher relaxivity values than Gd-DTPA with HSA. Gd-TTDA-BOM also caused higher and longer signal enhancement in aorta than Gd-DTPA. It is concluded that Gd-TTDA-BOM has a good potential to be a blood pool MRI contrast agent.