Assessment of image quality and radiation dose in some models of digital radiography systems – A Pehamed FLUORAD A + D phantom study

Digital radiography (DR) systems have been recently introduced as a developed technology that is replacing conventional film–screen systems in many countries around the world. Ideal situation in radiography is to maximize the image quality while minimizing the patient dose. The purpose of this study was to compare image quality and radiation dose in different digital radiography systems. Four different digital systems are compared in terms of their image quality performance and dose area product (DAP). Images of Pehamed FLUORAD A + D phantom were obtained for each DR system. Image quality parameters (contrast resolution (CR), spatial resolution (SR), and contrast-to-noise ratio (CNR)) and DAP were significantly different between different digital systems. It was shown that all four quantities increased with increasing exposure parameters in all systems. Image quality parameters of the SEDECAL system were higher than that in other systems (p ≤ 0.05). At the stable DAP (100 mGy.cm2), means of CR, CNR, and SR in the SEDECAL system were 6.38 ± 0.797, 29.70 ± 0.85 and 3.10 ± 0.38 lp/mm, respectively. The results of this investigation can be taken into consideration in the selection and purchasing of new systems in order to preserve patients as well as radiographers from unnecessary radiation dose

In vivo study of interferon-?, transforming growth factor-�, and interleukin-4 gene expression induced by radioadaptive response

Introduction: In the present study, the radioadaptive role of the immune system induced by low dose (LD) was investigated for its in vivo protective activity. Materials and Methods: Quantitative analysis of cytokine gene expression was assessed for their in vivo activity in BALB/c mice. To evaluate the adaptive response induced by LD on the mice spleen lymphocyte, the cytokine interleukin (IL)-4, interferon (IFN)-?, and transforming growth factor (TGF)-� expression was measured by a real-time quantitative polymerase chain reaction. To verify the radioadaptive effect of LD, animals were preirradiated at 10 cGy from a 60 Co source and then challenge dose at 200 cGy was delivered. Independent sample student's t-test was employed to compare cytokine gene expression in radioadaptive (10 + 200 cGy), LD (10 cGy), high-dose (HD, 200 cGy), and control groups of animals. Results: Following the HD, the cytokine gene expression of IFN-?, IL-4, and TGF-� was significantly decreased compared to the control group (P = 0.0001). However, TGF-� expression was also decreased significantly in the LD and adaptive groups compared to the control group (P = 0.0001). IFN-?/IL-4 ratio in the adaptive group was significantly decreased compared to the HD group (P = 0.0001). Conclusion: These results indicate that the immune system plays an important role for radioadaptive response induction by LD radiation to adjust the harmful effects of HD irradiation. © 2021 Journal of Cancer Research and Therapeutics | Published by Wolters Kluwer-Medknow