Method for the nondestructive measurement of small volumina within unregular shaped nonuniform subjects

This method permits the measuring of the mineral contents of bones. Nondestructive static determination of the electron density of small volumes is achieved in some medium surrounding this volume. To this end the principle of physics is applied which states that the intensity of the Compton scattering of an electromagnetic radiation source in a volume is directly proportional to the electron density in the volume according to the Klein-Nishina equation. The energy of the scattered radiation is smaller than that of the incident radiation and angle dependent. The absorption is corrected by computation. For measurement two gamma rays, e.g. from a Co-60 and a Cs-137 or Gd-153 source, crossing one another are used. By means of detectors the scattered radiation is measured in at least two points while the object is rotated through 180 deg. The crossing angle of the two rays is adjusted. (DG)