Technical Note: Impact on detective quantum efficiency of edge angle determination method by International Electrotechnical Commission methodology for cardiac x-ray image detectors

摘要: Purpose: Cardiac x-ray detectors are used to acquire moving images in real-time for angiography and interventional procedures. Detective quantum efficiency (DQE) is not generally measured on these dynamic detectors; the required “for processing” image data control of settings have been accessible. By 2016, USA hospital physicists will ability measure DQE likely utilize International Electrotechnical Commission (IEC) standard measuring imaging devices. The current IEC requires an a tilted tungsten edge test object obtain modulation transfer function (MTF) calculation. It specifies range angles use; however, it does specify preferred method determine this angle analysis. study aimed answer question “will my choice impact results?” Four different established determination methods were compared investigate DQE. Methods: Following standard, flat field acquired cardiac flat-panel detector calculate MTF noise power spectrum, respectively, Accuracy determining correct was ascertained using simulated with known angulations. Precision variability DQE, calculated via bootstrapping. Results: Three provided near equal same while fourth, angular difference 6%, had lower by 3% at 1.5 mm−1 spatial frequency 8% 2.5 mm−1; corresponding differences 6% 17% greater than deviations measurements. Conclusions: measurements may vary significant amount, depending when following methodology detector. most accurate precise recommended absolute assessments reproducible measurements, respectively.