Contribution of the Entropy Function to the Study of Collimator for Nuclear Medicine Imaging

Scintigraphic image currently used in the diagnosis or the evaluation process of tissues, is strongly dependant on several technical parameters specially collimator characteristics. The present work describes a numerical method, based on entropy function, able to specify depth and hole diameter of collimator as well as other geometrical parameters to get a better accuracy in scintigraphy evaluation. From the classical form of the entropy function, the entropy associated with a scintigraphic acquisition has been established. Its explicit expression includes collimator characteristics and source-collimator distance. The obtained numerical results and the performed illustrations explain the interest of the entropic approach, which takes into account both multiplex effect, counting process and spatial uncertainty. Acquisitions obtained on two kinds of collimator (general use and high resolution) by use of an uniform radioactive source, confirm the efficiency of such method in the choice of appropriate collimator.