Renal tubular damage detected by dynamic micro-MRI with a dendrimer-based magnetic resonance contrast agent

Background. A noninvasive technique to evaluate the structure and function of the kidney would be useful to investigate renal diseases, especially acute renal failure. We have developed a novel technique to visualize functional micro-magnetic resonance (MR) images of the mouse kidney with a dendrimer-based macromolecular renal MR contrast agent. Method. Mice were injected with cisplatin or vehicle, then examined three days later by contrast-enhanced, dynamic high-resolution micro-MRI with 160 μm spatial resolution using a 1.5 T clinical MRI unit, a surface coil, and the renal contrast agent G4D-(1B4M-Gd)₆₄. Results. The cortex and outer stripe of the outer medulla of the mouse kidney were clearly visualized in the normal mice. In animals treated with cisplatin, the gradation of tubular damage as assessed by contrast enhanced dynamic MRI correlated with renal function. Conclusion. Contrast-enhanced, dynamic high-resolution micro-MRI with a novel dendrimer-based macromolecular renal MR contrast agent can be a powerful tool for in vivo observation of renal structural and functional damage.