Evaluation and testing of computed radiography systems

Abstract

The implementation of film replacement digital radiographic imaging systems throughout Europe is now gathering momentum. Such systems create the foundations for totally digital departments of radiology, since radiographic examinations constitute the most prevalent modality. Although this type of development will lead to improvements in the delivery and management of radiological service, such widespread implementation of new technology must be carefully monitored. The implementation of effective QA tests on installation, at periodic intervals and as part of a routine programme will aid this process. This paper presents the results of commissioning tests undertaken on a number of computed radiography imaging systems provided by different manufacturers. The aim of these tests was not only to provide baseline performance measurements against which subsequent measurements can be compared but also to explore any differences in performance, which might exist between different units. Results of measurements will be presented for (1) monitor and laser printer set-up; (2) imaging plates, including sensitivity, consistency and uniformity; (3) resolution and contrast detectability; and (4) signal and noise performance. Results from the latter are analysed in relationship with both system and quantum noise components.

Application of dual energy method for non-destructive testing of materials designed to work in extreme conditions

“…Currently the digital radiography occupies one of the dominant positions among the different radiation NDT methods . The term "digital radiography" means the aggregate of radiation NDT methods and diagnostics, which converted at some point the radiation image of the testing object (TO) into a digital signal [5][6]. Subsequently, this digital signal is stored in computer memory and converted into two -dimensional array of measuring data, which can be subjected to various digital signal processing (contrast enhancement, scaling, antialiasing, and the like), and finally, it is reproduced on the display screen as halftone (or colour) image directly perceived by the operator.…”

Image quality, threshold contrast and mean glandular dose in CR mammography

“…The early detection of malignant calcifications and non-palpable breast masses requires images of very high quality (Mahesh 2004, Baldelli et al 2009, Li et al 2010. Technological developments of digital detectors have led mammography to move from screen film (SF) to digital radiology (Mahesh 2004, Noel and Thibault 2004, Pisano and Yafee 2005, Charnock et al 2005. However, it is well established that to achieve high-quality mammography, the following elements are essential: well trained and experienced personnel (radiologist, radiographer and medical physicist); modern and well-designed and in excellent working condition equipment; proper positioning; the exposure technical factors must be adequate selected according to the breast features; and appropriate image viewing conditions (IAEA 2011).…”