Рентгенология & Радиология, 2014, LIII 42-51

Quality assessment of the digitalization process of analog x-ray images

D. Georgieva

Computer-assisted diagnosis enabled doctors for a second point-of-view on the test results. This improves the diseases’ early detection and significantly reduces the chance of errors. These methods very nicely complemented the possibilities of digital medical imaging apparatus, but in analog images their applicability and results entirely depend on the quality of analog images digitalization. Today many standards and remarks for good practices discuss the digital apparatus image quality but the digitalization process of analog medical images is not a part of them.Medical imaging apparatus have become digital, but within an entirely digital medical environment is necessary for their ability to blend with the old analog medical imaging carriers. The life of patients doesn’t start with the beginning of digital era and for the aim of tracking diseases it is necessary to use the new digital images as well as older analog ones. For the generation of 40-50 years a large archive of images is piled up, which should be accounted of in the diagnosis process. This article is the author’s study of the digitalized image quality problem. It offers a new approach to the x-ray image digitalization – getting the HDR-image by optical sensor. After the HDR-image generation method offers to be used a digital signal processing to improve the quality of the final 16 bit grayscale medical image. The new method for medical image enhancement is proposed – it improves the image contrast, it increases or preserves the dynamic range and it doesn’t lead to the loss of small lowcontrast structures in the image.