Gd-DTPA-cascade-polymer: Potential blood pool contrast agent for MR imaging

Gadolinium‐DTPA (diethylenetriaminepentaacetic acid)‐cascade‐polymer, a potential new blood pool contrast agent for magnetic resonance (MR) imaging, was compared with a known blood pool agent, Gd‐DTPA‐polylysine, in an animal model. The relative signal intensities of liver, renal cortex, pancreas, and trunk muscle were assessed in 12 pigs between 4 seconds and 120 minutes after injection of a 20 μmol/kg dose of each contrast agent, by using a FLASH (fast low‐angle shot) sequence. Except for muscle, all tissues showed visible enhancement after injection of either contrast agent. After injection of Gd‐DTPA‐polymer, enhancement patterns in the liver, renal cortex, and pancreas were similar to those seen after injection of Gd‐DTPA‐polylysine. No statistically significant differences in enhancement between the two contrast agents were found at any time point. The authors conclude that the contrast kinetics of Gd‐DTPA‐cascade‐polymer are similar to those of Gd‐DTPA‐polylysine and that this agent may also be used as a blood pool contrast agent for MR imaging.