Effect of disk maturation on diffusion of low-molecular-weight gadolinium complexes: an experimental study in rabbits.

PURPOSE To measure the rate of enhancement in immature intervertebral disks in comparison with that of mature disks after intravenous administration of gadolinium-containing contrast media. METHODS Four rabbits were imaged with MR for 120 minutes after the injection of gadopentetate dimeglumine, gadoteridol, or gadodiamide. Contrast enhancement was measured in the lumbar intervertebral disks on each image. The rate and magnitude of enhancement in the immature and mature disks were compared. RESULTS Contrast enhancement was detected in intervertebral disks with all three contrast media. Enhancement was significantly greater in immature than in mature animals. CONCLUSION Greater enhancement in immature disks is consistent with a lower concentration of fixed negative charges in the glycosaminoglycans of the disk.