Abstract
In the last decades, digital radiography (DR) is becoming more popular in relation to traditional film screen radiography. This derives mostly from the fact that digital image is prone to post- processing analysis and it can also be stored for future use. Various organizations, such as the King’s Centre for the Assessment of Radiological Equipment in the United Kingdom (KCARE), the America’s Association of physicists in medicine (AAPM) and the Australian College of Physical Engineers in Medicine (ACPSEM), have published protocols in which guidelines concerning quality assurance and acceptance tests for digital systems are referred. These guidelines are presented here and other studies conducted from individual teams also referred, which either count on the mentioned protocols or have chosen to follow an alternative method. In addition, several patents relative to the description of the two different kind of DR, Computed Radiography (CR) and Digital Direct Radiography (DDR) systems, the phantoms and the image quality are also appeared. Apart from the quality control (QC) aspects that are also met in conventional radiography (entrance surface dose-ESD, tube performance controls and image presentation on the display units), diverse methods for quality assurance of digital radiography are presented as well. These different methods concern the image quality, the automatic exposure control (AEC) system and the detector’s performance. Moreover, representative phantoms utilized in clinical practice for QC of digital systems are also displayed and conditions are tested with diverse techniques.
Keywords: Direct digital radiography (DDR), computed radiography (CR), quality control, signal to noise ratio (SNR), contrast to noise ratio (CNR), image noise, ghosting erase, detective quantum efficiency (DQE) curve, automatic exposure control (AEC).
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