Physical image quality evaluation of a CCD-based x-ray image intensifier digital fluorography system for cardiac a

摘要

Abstract: An evaluation of the physical imaging performance of a prototype CCD-based TV camera (XTV16) cardiac Digital Fluorography system is presented. A tube-based TV camera (XTV11) operates in parallel, via a 50% mirror, allowing a direct comparison between the two different TV image recording technologies. The MTF, Noise Power Density (NPD) spectrum and the DQE of the system have been determined. The NPD analysis has been completed in both horizontal and vertical directions and, for completeness, a two dimensional noise analysis of the system has also been carried out. An audit of the main sources of noise in the systems is presented. The effectiveness of image corrections in minimizing systematic noise due to the CCD camera is demonstrated. The DQE spectra of both systems at zero frequency are X-ray quantum noise limited and they are both operating dose efficiently. The DQE spectrum in the horizontal direction of the XTV16 at high spatial frequencies is shown to be superior to that of the XTV11 which may translate to improved rendition of small features in clinical images. The CCD camera system described here s now used in the Cardio-Vascular systems of a major European company. !6