Application of Phosphors in X-ray Computed Tomography

Abstract

One of the most attractive applications of phosphors is their use as X-ray conversion detectors in X-ray computed tomography (CT), the dominating method of medical radiology. For the last few years a new class of phosphors based on ceramic materials has been introduced by several groups for CT use. For example, Europium-doped Yttriagadolinia ceramics, Y₂0₃-Gd₂O₃:Eu are chosen to demonstrate the afterglow problem. In many cases the afterglow behvior of such phosphors is affected by excitation conditions. By high energy excitation with photons up to 150 keV defects are generated which may act as trapping centers increasing afterglow. For the next generation of high performance CT systems an improvement of afterglow is of special interest.