AbstractID: 9027 Title: Performance Testing of the Flat Panel Detector in Cardiovascular Imaging
The flat panel detector is replacing the image intensifier in cardiovascular imaging. Image quality and patient radiation dose are areas
of concern when justifying a purchasing decision. The performance of both a-Si and a-Se detectors, from several manufacturers, were
evaluated using an NEMA XR 21 phantom that is specifically designed for the cardiovascular x-ray equipment. It standardizes the
phantom setup geometry and test criteria. For image quality, the results of high contrast resolution (line pair pattern), low contrast
resolution (iodine-embedded disk) and clarity of the moving wires (rotating spoke) were analyzed. To assess the patient radiation
dose, the detector input radiation level and patient skin entrance exposure were measured. It was found that the fluoroscopic
technique (kVp, mA, pulse rate, pulse duration, AEC design, x-ray filtration, etc.) often predominates the results. If all other
conditions are equal, using more radiation always boosts image quality. There was a significant difference in test results even for the
same manufacturer. The performance may be limited or determined by the fluoroscopic setup that is beyond the physicist’s control.
Nevertheless, while achieving the minimum performance criteria in image quality, the better system that uses least amount of radiation
will emerge. Such criteria yet remain to be developed. It makes sense to compare the current flat panel detector with a well-calibrated
image intensifier using the same NEMA phantom. The flat panel detectors show some, but not spectacular, improvement of high
contrast resolution. However, there was no reduction in patient radiation dose.