title: A quantitative evaluation of rheumatoid arthritic activity with Tc-99m HEDP.
abstract: In an attempt to develop a quantitative method of evaluating rheumatoid arthritic activity, Tc-99m HEDP joint uptake values and joint-to-bone ratios were studied in ten adult rheumatoid arthritic patients and 17 nonarthritic patients. A joint-to-bone activity ratio of 1.8 at the fourth hour after injection (RA Index) discriminated clinically active rheumatoid arthritic joints from control joints with 95% accuracy. Serial studies on five patients during drug trial demonstrated a positive correlation between RA Index and the clinical manifestations of rheumatoid arthritic activity. The RA Index may be a useful quantitative parameter for evaluation of rheumatoid arthritic activity following therapy.
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000378:metabolism; D012968:Etidronic Acid / Q000378:metabolism; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013667:Technetium / Q000378:metabolism; D013679:Technology, Radiologic
chemical_list: D013667:Technetium; D012968:Etidronic Acid