Factors influencing pertechnetate uptake by rabbit knees

The accumulation of radioactivity over rabbit knees immediately after the injection of 99mTc-pertechnetate or one of two 99mTc-labelled particulate preparations has been measured in animals with and without experimental arthritis. The results indicate that in inflamed, but not normal joints, a peak of radioactivity is detectable within 9 seconds of injection and suggest that the rate of accumulation of radioactivity over the joint may be a more sensitive indicator of inflammatory activity than measurement at a fixed time. Clearance from the circulation and tissue distribution of the three radioactive preparations were also measured.