Avaliação de testes de controle de qualidade em placas de imagem do sistema de radiologia CR

Abstract

Quality control of radiographic equipment is essential to ensure the quality of medical images and is essential to ensure diagnostic reliability. The quality of the image, which can be considered radiologically as “the accuracy in the anatomical representation of the patient”. For this purpose, an image acquisition detector must have specific technical characteristics, to enable an accurate diagnosis from the doctor to the patient. Considering the guarantee of the quality necessary for diagnostic imaging, in this work we evaluated quality control tests previously carried out by a large teaching hospital, located in Curitiba/PR, to investigate the possible correlation between an increase in the number of exposures of image plates of the indirect digital radiography system – CR with a decrease in the quality of the radiographic image. The tests evaluated were plate uniformity, signal-to-noise ratio deviation, difference in sensitivity between phosphor plates and accuracy of the detector’s dose indicator. All test values were grouped in a spreadsheet in the Microsoft Office Excel program and then the dispersion graphs were obtained, which allowed the evaluation of the correlation through the Spearman coefficient (ρ) and statistical significance. Through the results obtained, it can be observed, for the range of amount of exposures studied, that there is no relationship between a bad result in the QC test of the plates, that is, their degradation, with an increase in the amount of exposures. On the contrary, the plates with lower amounts of exposure (0-2000) were the ones that presented the lowest performance in the QC tests. This correlation can be explained by hypotheses such as: different uses of image plates, in exams that demand a higher dose of exposure, or a need for “softening” the image plates in the first uses, which would be essential for there to be an accommodation of the matter and increase its useful life. Therefore, this work may contribute to future studies on the integrity of CR plates, especially regarding the hypothetical results raised about the lower performance of plates that have fewer exposures.