99mTechnetium scintiphotography in arthritis I. technic and interpretation

A technic for visualization of inflamed joints using intravenously injected technetium‐99m as pertechnetate and an Anger (scintillation) camera for detection will be described. Contrast between inflamed and normal tissue was usually greatest in the first few minutes after isotope injection, presumably, at the time of maximal difference in concentration of 99mTc between blood and extravascular tissue. Inflamed joints with moderate to large effusions were often visualized best 1–2 hr after injection. The extensive binding of pertechnetate by plasma and joint fluid proteins found in equilibrium dialysis experiments was evoked as an explanation of this phenomenon.