323 ASSESSMENT OF INFLAMMATORY ACTIVITY IN KNEE JOINT
SIR,-A frequent obstacle to the study of arthritis is the lack of objective measures of severity. We have been testing a method for rapid assessment of the inflammatory activity in the knee joint,’ based on the technetium 99m pertechnetate (99"’TCO4 ) uptake technique2 which we modified. Two collimated thallium-activited sodium-iodide crystals were used to detect the y-radiation of the 99ffiTc in the knee joint as a function of time after intravenous injection of 200 tiCi 99C04 -. The patient rested for an hour beforehand to improve the reproducibility of the test. Radioactivity in the knee joint was measured shortly after injection (2tmin) or at 30 min at most. We investigated twenty-three healthy volunteers, twentytwo patients with clinical evidence of monoarticular arthritis, and twenty-four patients with bilateral arthritis. Radioactivity, shortly after injection of 99ffiTc04- was significantly lower in the knee joints of controls (mean 54.2±; S.D. 10.9 c.p.m./[,Ci) than in clinically inflamed knee joints in patients with monoarticular arthritis (93-3±17-7) or bilateral arthritis (96.1±28.7) (P
SIR,-A frequent obstacle to the study of arthritis is the lack of objective measures of severity. We have been testing a method for rapid assessment of the inflammatory activity in the knee joint,’ based on the technetium 99m pertechnetate (99"’TCO4 ) uptake technique2 which we modified. Two collimated thallium-activited sodium-iodide crystals were used to detect the y-radiation of the 99ffiTc in the knee joint as a function of time after intravenous injection of 200 tiCi 99C04 -. The patient rested for an hour beforehand to improve the reproducibility of the test. Radioactivity in the knee joint was measured shortly after injection (2tmin) or at 30 min at most. We investigated twenty-three healthy volunteers, twentytwo patients with clinical evidence of monoarticular arthritis, and twenty-four patients with bilateral arthritis. Radioactivity, shortly after injection of 99ffiTc04- was significantly lower in the knee joints of controls (mean 54.2±; S.D. 10.9 c.p.m./[,Ci) than in clinically inflamed knee joints in patients with monoarticular arthritis (93-3±17-7) or bilateral arthritis (96.1±28.7) (P
