Nuclear medicine studies of aging--VII. Humeral deltoid tuberosity on bone scans and radiographs.

Because of the occasional finding of increased deposition of bone imaging agent in the area of the humeral deltoid tuberosity, we analyzed both bone scans and radiographs to determine if there were age related correlations. Only 29% of patients of age 35 years or younger showed any radiographic evidence of deltoid tuberosity. This increased to 48% in the 36-64 y age group (and 46% in those of age 65 y and above). Bone scans (99mTc-MDP) of the humerus showed that 26% of individuals of ages 20-39 y had increased uptake in the deltoid tuberosity area. The figure was 21% of those in the 85-94 y age group. However, distribution between sexes in the 20-39 y age cohort was asymmetric (44% of males showed the bone scan finding, but only 15% of the females). We then reviewed cases that had shown the most prominent deltoid tuberosity on humeral radiographs. Thirteen of the 14 cases (93%) were males. Deposition of bone imaging agent in the deltoid tuberosity region was thus only slightly correlated with age (more common after age 35 y), but strongly correlated with sex (males more common) in all three major age groups (35 and under, 36-64, and 65 years and over). Possible interrelations with bone size and muscle mass were pointed out.