Peripheral joint scanning with technetium pertechnetate. Application in clinical practice

Results of a prospective study to evaluate the clinical usefulness of radioisotope joint scanning in the practice of rheumatology are reported. The radiopharmaceutical used was technetium pertechnetate, increased synovial blood flow being the main contributory factor to abnormal joint images. Strict adherence to a procedural protocol was necessary to assure reproducible images. Joint scintigraphy was performed on 56 control subjects without joint disease and 51 patients with different rheumatic disorders. There was excellent agreement between clinical examination and joint scintigraphy in all groups studied. In cases of disagreement, the joint scintigram generally was more sensitive. This high sensitivity for the detection of synovitis was accompanied by a lack of specificity, because it failed to diagnose the nature of the joint involvement. The joint scan was helpful for diagnosing early or steroid-suppressed synovitis and also for suspected nonarticular rheumatism. It aided in delineating the pattern of joint involvement. Joint scintigraphy is the only objective nontraumatic permanent record documenting joint inflammation.