Evaluation of 67Ga accumulation around the shoulder joint

67Ga scintigraphy was performed in 865 patients, and in 1078 examinations. 67Ga accumulation was evaluated retrospectively for asymmetric accumulation in the shoulders. Approximately 50% of patients showed no asymmetric distribution of 67Ga in the shoulders. About 40% of patients showed increased accumulation in the right side and about 10% of patients showed increased accumulation in the left side. A change of 67Ga distribution in the shoulder joints was recognized in about 30% of patients during the follow-up study. Reasons for asymmetric distribution of 67Ga in the shoulders were considered to be due to bone metastasis, changes of local blood flow, edema, irradiation, muscle atrophy after cerebral paralysis, and operation. 67Ga scintigraphy showed a broader range and more prominent accumulation in the soft tissues around the shoulder joint than 99mTc-MDP scintigraphy. The accumulation of 99mTc-MDP was recognized to be in the center of the region of 67Ga accumulation. 99mTc-MDP scintigraphy showed more prominently increased accumulation than 67Ga scintigraphy in patients with osseous lesions. Similar factors appeared to have had an influence on the abnormal accumulation of 67Ga and 99mTc-MDP around the shoulder joint. (author)