Quantitation of arthritis by 99mTc-uptake measurements in the mouse knee-joint: correlation with histological joint inflammation scores.

A method is described to detect and to quantitate inflammation in knee-joints of mice. Approximately 10 muCi 99mTechnetium pertechnetate (99mTc) is injected subcutaneously in the neck region and the accumulation of the short-lived isotope in the knee-joint is detected by external gamma counting. 99mTc-uptake values correlate well with histological grading of joint inflammation at various intervals after induction of the inflammation. The method can be used to detect changes in activity of unilateral as well as bilateral joint inflammation using either the ratio of 99mTc uptake in the right knee versus that in the left knee or absolute 99mTc-uptake values.