Evaluation of various contrast agents for improved arthrography.

In the canine knee joint the monomer methylglucamine iothalamate, the dimer methylglucamine iocarmate, and the nonionic contrast agent metrizamide were examined for use in arthrography. A total of 104 injections were performed with equal iodine concentrations (280-282 mg/ml) and volumes (4 ml) of the three contrast agents. These were evaluated using radiographic comparison and iodine estimations of the joint fluid at various times after injection. Radiographically the dimer was superior, followed by metrizamide and then the monomer. The greatest amount of total iodine within the joint fluid at various times after injection was found with the dimer. Iodine concentrations in the joint fluid were similar for the dimer and metrizamide, both greater than with the monomer.