Ioxaglate Sodium

Ioxaglate, a negatively charged ionic iodine dimer, was used as a contrast agent for in vivo imaging of cartilage degeneration with micro-computed tomography arthrography in a rat model. The negatively charged ioxaglate molecules were locally repulsed by the negative fixed charge density of healthy cartilage, which is determined by the glycosaminoglycan content. Consequently, ioxaglate penetration into the cartilage was inversely related to the glycosaminoglycan content, and the agent diffused into the cartilage matrix at sites where glycosaminoglycan depletion occurred. In vivo μCT-arthrography clearly detected cartilage degeneration in the rat knee-joints, with higher μCT-attenuation values and smaller total volumes of the cartilage layer detected at longer time periods after cartilage degeneration was induced.
Ioxaglate remained visible in the knee cavity for over 200 minutes, allowing for sufficient imaging time. This technique could distinguish different stages of cartilage degeneration and was quantitatively confirmed by histology, demonstrating that the anionic ioxaglate can visualize cartilage degeneration through its differential diffusion into degenerated tissue.

Fig. 1 Representation of different ROIs from the μCT-arthrogram and the patellar cartilage layer from the histological sections. (Piscaer T M.; et al. 2008)