[Radioisotopic study of bone growth and maturation. 160 cases]

Increases in blood supply, and certain metabolic and physical processes, are of special significance in epiphyseal growth centers. Such events are evidenced by the uptake of 99mTc methylene diphosphonate (MDP). Bone scans in children and young adults show increased radionuclide uptake in epiphyseal growth plates. Age-related changes in 99mTc MDP epiphyseal uptake can be used for determining a functional bone age. Radiation exposure is within the range of other routine diagnostic procedures. Scanning was done with a gamma scintillation camera, which supplies rapid, high resolution, studies. In the first five years of life, nearly all the main epiphyseal growth plates were visible symmetrically on routine scans. In six cases, growth plates were visible before the corresponding epiphyseal ossification foci became apparent on roentgenograms. Little bones (hands, wrists, feet, and ankles) were not assessed because of the poor resolution of the parallel collimator-camera system. A slow decrease in epiphyseal growth plate activity was demonstrated in subjects over sixteen years of age. In some instances, this decrease occurred only after epiphyseal closure became visible on roentgenograms. Data described here are not usually employed for clinical purposes, except when viability of a growth plate is doubtful. Functional analysis with 99mTc MDP is a useful complement to roentgenologic investigation of skeletal growth and maturation.