Development of Mammography System Using CdTe Photon-Counting Detector for Exposure Dose Reduction: Evaluation of Image Quality in the Prototype System

摘要

We discuss a new mammography system using a cadmium telluride (CdTe) photon-counting detector for exposure dose reduction. We created a prototype system that uses a CdTe detector and an automatic moving stage. For a variety of conditions, we measured the image properties and evaluated the image quality produced by reconstructing scanning images from several thousand frame data elements obtained by shift-and-add method, from which it was demonstrated that the basic detector performance in terms of output linearity with respect to X-ray intensity was good. The spatial resolution under various conditions and the linearity of the relationship between the thickness of the acrylic step and reconstructed scanning images were also measured. Finally, we evaluated the image quality obtained by scanning a breast phantom. Our results show that the developed prototype system can improve image quality by optimizing the balance between the shifting-and-adding operation and the output of the X-ray tube.