Photon transmission tomography techniques for screening organs in biological specimen banking.

Biological specimen banking methodology dictates that when a number of specimens of a particular type are available then the selected specimen be representative of the population in question. It is apparent though that this sorting process may present a formidable task which can be facilitated by employing tomographic transmission techniques using photons. Thus it is possible to discriminate between and discern abnormalities in specimens by obtaining the distribution of the photon linear attenuation coefficient, a function of atomic number and physical density, in sections through the specimen whilst maintaining its integrity. Fresh and freeze-dried specimens of porcine kidney were initially examined under differing temperature conditions using a single point photon transmission method, which was not successful due to the heterogeneity of the tissues. Whereas photon transmission tomography is shown to be well suited in testing for homogeneity, highlights the importance of scanning before cryogenic treatment and provides the possibility of monitoring tissue status over storage period by observing small changes in linear attenuation coefficient.