Natural D‐glucose as a biodegradable MRI relaxation agent

Purpose Demonstrate applicability of natural D‐glucose as a T 2 MRI contrast agent. Methods D‐glucose solutions were prepared at multiple concentrations and variable pH. The relaxation rate ( R 2  = 1/ T 2 ) was measured at 3, 7, and 11.7 T. Additional experiments were performed on blood at 11.7 T. Also, a mouse was infused with D‐glucose (3.0 mmol/kg) and dynamic T 2 weighted images of the abdomen acquired. Results The transverse relaxation rate depended strongly on glucose concentration and solution pH. A maximum change in R 2 was observed around physiological pH (pH 6.8‐7.8). The transverse relaxivities at 22°C (pH 7.3) were 0.021, 0.060, and 0.077 s −1 mM −1 at 3.0, 7.0, and 11.7 T, respectively. These values showed good agreement with expected values from the Swift‐Connick equation. There was no significant dependence on glucose concentration or pH for T 1 and the diffusion coefficient for these solutions. The transverse relaxivity in blood at 11.7 T was 0.09 s −1 mM −1 . The dynamic in vivo experiment showed a 10% drop in signal intensity after glucose infusion followed by recovery of the signal intensity after about 50–100 s. Conclusion Glucose can be used as a T 2 contrast agent for MRI at concentrations that are already approved for human use. Magn Reson Med 72:823–828, 2014. © 2014 Wiley Periodicals, Inc.