[Analysis of bone calcium by localized neutron activation in the hand and dorsal spine].

The measurement of the mineral content of bone by localised neutron activation was performed in the hand in 58 women aged between 23 and 87 years and simultaneously in the hand and the thoracic spine (from the 5th to the 9th thoracic vertebra) in 46 women aged between 50 and 80 years, all free of any bone disease. The neutron flow was emitted by Californium 252. The bone calcium mass was calculated from the peak of radioactivity emitted by Ca 49 with an energy of 3.10 MeV, measured by means of a sodium iodide scintillation detector. The bone volumes were estimated indirectly by planimetry. The results were expressed as the volumic concentration of calcium in the bones of the hand and the vertebrae. The calcium concentration of the bones of the hand decreases with age, especially between 50 and 60 years. The calcium concentration of the vertebrae decreases more markedly with a significant negative correlation (r = - 0.550; p less than 0.05). The correlation is particularly significant (r = - 0.878) in the 16 women aged between 50 and 65 years with a calcium concentration in the bones of the hand within the normal range. The correlation between the calcium concentration in the vertebrae and age was no longer significant after the age of 65 years, whatever the value of the calcium concentration of the bones of the hand. A significant correlation (r = 0.660; p less than 0.05) was observed between the vertebral calcium and the calcium in the bones of the hands in women aged between 50 and 65 years, which disappeared after this age.(ABSTRACT TRUNCATED AT 250 WORDS)