Radioisotope study of small joint inflammation in rheumatoid arthritis.

Radioactive technetium (9QmTc), introduced into nuclear medicine in 1964 (Harper, Beck, Charleston, and Lathrop, 1964), has been used to visualize many organs (McCready, 1967), including the thyroid gland (Andros, Harper, Lathrop, and McCardle, 1965), the salivary glands (Harden, Hilditch, Kennedy, Mason, Papadopoulos, and Alexander, 1967b), the stomach (Harden, Alexander, and Kennedy, 1967a; Irvine, Stewart, McLoughlin, and Tothill, 1967), the liver (Sorensen and Archambault, 1963), the brain (Davis, Alexander, Witcofski, and Maynard, 1966), the placenta (Larson and Nelp, 1965), and the joints (Weiss, Maxfield, Murison, and Hidalgo, 1966; Alarc6n-Segovia, Trujeque, Tovar, and Adame, 1967; Whaley, Pack, Boyle, Dick, Downie, Buchanan, and Gillespie, 1968; McCarty, Polcyn, and Collins, 1970a; McCarty, Polcyn, Collins, and Gottschalk, 1970b). Technetium scintiphotography of finger and wrist joints and knees in rheumatoid arthritis has shown increased uptake in the joints which reflected the degree of inflammatory involvement at the time of study (Weiss and others, 1966; Alarcon-Segovia and others, 1967; McCarty and others, 1970a), and Whaley and others (1968) have described a technique for quantitating the joint scintiphotographs. Scintiphotography of joints has the major disadvantage of requiring doses of the order of over one millicurie of 99mTc to obtain adequate contrast between inflamed and normal joints (Whaley and others, 1968; McCarty and others, 1970a) and quantitation of the scintiphotographs is tedious and time-consuming. Recently, Dick, Neufeld, Prentice, Woodburn, Whaley, Nuki, and Buchanan (1970) have reported a method of quantitation in the knee joint based upon the uptake of 99mTc by the joint as measured by continuous external directional counting after the intravenous administration of approximately 40 uci of the isotope. This method was shown to be reproducible when repeat measurements were made within 24 hrs, to reflect differences between normal and inflamed joints affected by rheumatoid arthritis, and to be capable of reflecting the effects of intra-articular injection of corticosteroids (Dick and others, 1970). In this paper we describe similar studies carried out on the proximal interphalangeal joints.