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New Compensation Principles for Enhanced Image Quality in Industrial Radiology with Digital Detector Arrays

Contrast-to-noise ratio (CNR) management is the key element for image quality control in digital radiology. Modern digital detector array calibration techniques allow an extraordinary increase of CNR in comparison to other digital detectors and film. Contrast reduction due to an increase in X-ray energy can be overcompensated for by noise reduction. This enables the reduction of acquisition time and increase of the thickness range per radiograph. Even limitations in the spatial resolution, constrained by the individual picture element (pixel) size of the detector, can be compensated for with an increased CNR. Bad pixel management of digital detector arrays in combination with CNR enhancement enables the safe application of this technology for film replacement. Considering these points, three compensation principles have been formulated for the implementation of digital detector arrays as a viable film replacement technology. The first is compensation of reduced contrast (μeff) by increased signal-to-noise ratio (SNR): if optimization of contrast cannot be achieved, the noise must be reduced (increased SNR); if contrast can be increased, there is more tolerance for higher noise (moderate or lower SNR can be used). The second is compensation of insufficient detector sharpness (high unsharpness) by increased SNR. The third is compensation of interpolation unsharpness due to bad pixel correction by increased SNR.

References
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