Partial body calcium determination in bone by proton activation analysis

Abstract
The feasibility of a new method for in vivo regional bone calcium measurement has been studied in phantoms using the 160 MeV Harvard cyclotron. Advantages include the capability of measuring bone calcium directly in a well defined anatomical region and restriction of the dose to the immediate region of interest. Proton activation of 40Ca (97% natural abundance) produces 38K. Its 2.17 MeV gamma ray (T1/2=7.71 min) is detected by a NaI counter. Separation of this activity from room background and interfering nuclides, 14O and 34Clm, proceeds by decay curve analysis.