Radiography Technology Research Articles

Spontaneous imbibition of unsaturated sandstone under different vertical temperature gradients: neutron radiography experiments and dynamic models

To elucidate the imbibition behavior of water in complex temperature and stress environments, spontaneous imbibition experiments were conducted on unsaturated matrix sandstones at different vertical temperature gradients by neutron radiography technology. Additionally, corresponding dynamic models of water imbibition in porous media were established. The research results reveal the phased characteristics of sandstone spontaneous imbibition and the influence of vertical temperature gradient on the evolution of wetting front. Specifically, the initial development speed of the wetting front increases with an increase in the vertical temperature gradient, indicating a direct relationship. However, the growth rate of the wetting front gradually slows down with increasing time, eventually reaching a saturated state. Model validation demonstrates that the traditional Washburn's law is still valid in isothermal conditions without temperature gradient (G=0). Further analysis indicates that the imbibition rate has a direct correlation with linear thermal expansion coefficient (α) and viscosity temperature coefficient (β) across various vertical temperature gradients, and an inverse correlation with surface tension temperature coefficient (γ). Furthermore, when the values of α, β, and γ fall below 0.001, their impact on the imbibition rate becomes negligible. The sensitivity of the imbibition rate to parameters γ, β, and α decreases in that order, with γ being the most sensitive, followed by β, and α being the least sensitive. Moreover, the relative importance of α, β, and γ dictates their specific influence on the imbibition rate, and a synergistic effect exists among these parameters, which collectively influence the water absorption behavior of sandstone.

Is digital mammography reducing radiation doses to women?

This study aims to investigate the impact of national quality programs in mammography and technological advances in digital mammography units on the radiation doses delivered to women in Brazil. Radiation dose assessments in mammography units were conducted through a mail-based dosimetric system. For each unit of facilities that applied to one of the two national quality programs, a postal dosimetric system is dispatched, comprising an optically stimulated luminescent dosimeter (OSL) attached to the surface of a 4.0 cm thick polymethyl methacrylate (PMMA) phantom, simulating a compressed breast with 4.5 cm thickness. Testing instructions to expose the dosimetric phantom for assessing the mean glandular dose (MGD) are provided. Between 2012 and 2023, the programs evaluated the MGD in 1,687 mammography units of computed radiography (CR) and direct digital radiography (DR) technologies from 1,399 facilities located in all Brazilian regions. A total of 1,660 (70.5%) evaluations were carried out on CR technology mammography units and 696 (29.5%) on DR units, totaling 2,356 MGD evaluations. The overall average MGD was 1.60 ± 0.80 mGy, with 1.68 ± 0.83 mGy for CR technology and 1.42 ± 0.68 mGy for DR technology. A comparison of average MGD between the periods 2012 - 2018 and from 2019 onwards shows a dose reduction of 8.6% for CR systems and of 26.0% for DR systems (p = 0.000). As CR systems use analog mammography units, which did not undergo technological advances between the two periods, the reduction in doses observed is due to the actions of national quality certification programs and by using image plates for dual-sided reading or needle-based image plates. The reduction observed in DR systems is due to both national quality programs and technological advances in mammography units, especially the use of radiation beams generated by X-ray tubes with tungsten targets.

Sex Determination through Pelvic Bone Using Anteroposterior Radiographs

Background: Forensic anthropology uses digital radiography to identify victims' gender, despite the population-specific nature of determining gender from bones, offering a cost-effective and straightforward method. The objective of the study was to evaluate the accuracy of the digital radiography technology for sex recognition of the selected participant group in Hyderabad, Sindh Time and location: Cross-sectional study conducted by department of Forensic medicine Liaquat University of medical and Health Sciences Jamshoro and Isra University Hyderabad at the outpatient of Liaquat University hospital, Hyderabad from February to May 2023. Methods: The study included male and female patients aged 18-50 years and was authorized by the Research and Ethics Committee LUMHS. Study participants were divided into two groups; male and female. Differences in pelvis bone fragments parameters like iliac height, inter-acetabular distance, pelvic inlet (breadth), acetabulum diameter, pubic length, Ischial length and ischio-pubic index on digital x-ray radiographs of both groups were examined and compared. Results: A statistically significant difference (p<0.05) in bony prominence parameters including inter-acetabular distance, acetabular diameter, breadth of the pelvic inlet, pubic length, ischial length and ischio-pubic index was observed between group A and group B. The study revealed that the accuracy in recognizing male individuals through ileum height (68.8%), inter-acetabular distance (64.7%), and the pelvic inlet breadth (61.0 %) Conclusion: The iliac height, inter-acetabular distance, pelvic inlet (breadth), inter-acetabular diameter, pubic length, Ischial length and ischio-pubic index on radiographs (x-rays) of pelvic bones are a reliable bone fragments parameters in sex determination with high precision.

REPEAT RADIOGRAPHY ANALYSIS AND CORRECTIVE MEASURES IN A PRIVATE MEDICAL COLLEGE AND TEACHING HOSPITAL

Aims and objectives: The primary goal of this study is to identify the body parts that undergorepeated radiographic examinations the most frequently and the prevalent causes of these examinations. Materials and Methods: A prospective study was carried out in the Department of Radio-Diagnosis and Imaging to investigate the reasons behind repeated radiography in a private university hospital in India. A total of 6832 samples were evaluated between November 1, 2021, and April 30, 2022. Discussion: Repetition of a patients radiographic projection can be caused by several circumstances. The common factors found in this study are collimation error, wrong centering, patient motion and incorrect positioning, appearance of artifacts owing to insufficient patient preparation at times and patient non-cooperation like patient motion. Repeat radiographs using the computed radiography technology are influenced by a plethora of circumstances. These variables include technical parameters chosen,the patients Body Mass Index (BMI)and the patients level of preparation. Conclusion: Repeat radiography plays an important role as a key indicator in evaluating the quality of the service provided by the medical imaging department and gives us an insight on whether the dose rates are within the given guidelines or not.

Interfacial failure behavior of Thermal Barrier Coatings (TBCs) at high temperatures: An in-situ indentation study based on X-ray imaging

Interfacial failure behavior is a major concern during the service of thermal barrier coatings (TBCs). Quantitative study on interfacial failure behavior of TBCs at high temperatures remains a great challenge. In this study, an in-situ high-temperature cross-sectional indentation (HCSI) method based on X-ray imaging was developed. The out-of-plane displacement of TBCs was measured by in-situ digital radiography (DR) technology. The morphology of the interfacial crack was characterized by an in-situ computer tomography technology. It was found that the interfacial fracture region tended to be semi-elliptical shaped. The strain energy during HCSI was quantified and analyzed by finite element analysis (FEA). The composite stress intensity factor (SIF) and the mixed modal angles at high temperatures were obtained by analyzing the stress field at the crack tip. Interfacial toughness of TBCs at RT, 400 °C, and 800 °C were obtained. The interfacial toughness changes little ranging from RT to 400 °C, while it sharply decreases ranging from 400 °C to 800 °C. A prediction model for the evolution of interfacial toughness with temperature was obtained. The competition mechanism of interfacial cracks at different temperatures was discovered. The relationship between the change in interfacial toughness and the failure mode evolution was discussed.

Utilizing mobile digital radiography for detection of thoracolumbar vertebrae traits in live donkeys.

It has been well-established that the number of vertebrae is associated with body size and meat productivity. In current study we utilized a digital radiography (DR) technology to detect the number of thoracolumbar vertebrae in live donkeys. For this purpose, we introduced for the first time a groundbreaking device designed by our team for assessing thoracolumbar vertebrae number traits in equids, employing a sample of 1,000 donkeys sourced from five distinct donkey farms. This assessment incorporates a range of crucial body metrics, including body height, length, and various other measurements. Subsequently, our study determined the number of thoracolumbar vertebrae in 112 donkeys, utilizing the DR system. These findings were further validated through post-mortem evaluations conducted by slaughtering the donkeys. Our findings demonstrated a remarkable resemblance between the thoracolumbar vertebrae numbers visualized through the DR system in live donkeys and those obtained via slaughter verification. In conclusion, this research underscores the accuracy and effectiveness of the DR system for the detection of thoracolumbar vertebrae in live donkeys, which might be helpful for assessing the body size and meat productivity. We also recommended the utilization of DR system for counting thoracolumbar vertebrae in other animals in live state and could be a useful addition to livestock business industry for the prediction of body size and meat productivity efficiency.

A simple and effective method for the removal of gamma white spots noise in fast neutron images

Fast neutron radiography technology has unique application advantages in the field of non-destructive testing. However, due to the interaction between the gamma rays and the charge-coupled device camera, a large amount of gamma white spots noise is attached to the fast neutron images, which affects the subsequent analysis. In this paper, we propose a simple and effective method to remove gamma white spots noise in fast neutron images. First, the image is down-sampled by the dilated down-sampling method to reduce the influence of noise. Then, the existence of gamma white spots noise is accurately identified by noise detection. Finally, the image is denoised using an improved median filtering method. In order to verify the performance of the proposed method, several commonly used noise reduction methods and the proposed method are used to conduct test experiments on both simulated and fast neutron images, and several image quality evaluation indices are used for quantitative assessment. The results show that the proposed method not only performs well in visual effects but also achieves satisfactory results in evaluation indices.

Radiation Dose and Image Quality with Exposure Factor Variation Using a Virtual Grid in Digital Radiography

Digital radiography technology provides many advantages. However, there are still frequent repetitions of inspections due to failure to determine the exposure factor due to a decrease in image quality. Virtual Grid is a digital radiographic image processing technology that converts image quality that is deteriorating due to X-ray scattering to better image quality by reducing the effects of X-ray scattering. Application of a virtual grid can contribute to improving image quality and increasing the procedural efficiency of the workflow in a radiographic examination. This study uses a research-experimental design, with a One-Shot Case Study. The sample selection of 60 samples was carried out randomly by judgmental or purposive sampling. The sampling technique was carried out with specific considerations for the research objectives to determine the optimal exposure factor by using a virtual grid for the skull, lumbar, and pelvic radiographic examinations. Then, it was analyzed quantitatively and qualitatively visually by three radiologists—a bivariate analysis of data using one-way ANOVA. Qualitative analysis was carried out as well as a test. Feel free to assess the agreement of the informants. Results In the quantitative and qualitative analysis, the exposure factor and the ideal virtual grid ratio for optimization are skull AP: 106 kV, 2 mAs, ratio 14:1, skull lateral: 106 kV, 1.25 mAs, ratio 14:1, skull lumbar AP: 106 kV, 4 mAs, ratio 14:1, skull lumbar lateral: 113 kV, 6.3 mAs, 10:1 ratio, and pelvis AP: 92 kV, 8 mAs, 14:1 ratio.

Laser-driven double shock loading and diagnosis technology for material ejection from surface

The physics of shock-induced ejection is a crucial phenomenon in the field of shock compression science and technology. Limited by loading methods, the previous research primarily focused on the physics of ejecta induced by single shockwave, with few data available on multiple shockwave loading conditions. To solve this problem, we proposed a double shockwave production method based on the high-intensity laser facility, which allows the interval time between the shock waves to be adjusted in the nanosecond to microsecond timescale. Meanwhile, we applied loading techniques to study the ejection behavior of metal tin and integrated photonic doppler velocimetry and high-energy x-ray radiography technology to observe the ejection process. By comparing the experimental results for single and double shockwave, the multiple shock-induced ejection features have been clearly confirmed. Our experimental results provide valuable insight into the behavior of ejecta under multiple shockwave loading conditions, which is of great significance for deepening our understanding of the ejection mechanism.

Non-Destructive Internal Defect Detection of In-Shell Walnuts by X-ray Technology Based on Improved Faster R-CNN

The purpose of this study was to achieve non-destructive detection of the internal defects of in-shell walnuts using X-ray radiography technology based on improved Faster R-CNN network model. First, the FPN structure was added to the feature-extraction layer to extract richer image information. Then, ROI Align was used instead of ROI Pooling for eliminating the localization bias problem caused by the quantization operation. Finally, the Softer-NMS module was introduced to the final regression layer with the predicted bounding box for improving the localization accuracy of the candidate boxes. The results of the study indicated that the proposed network model can effectively identify internal defects of in-shell walnuts. Specifically, the discrimination accuracies of the in-shell sound, shriveled, and empty-shell walnuts were 96.14%, 91.72%, and 94.80%, respectively, and the highest overall accuracy was 94.22%. Compared to the original Faster R-CNN network model, the improved Faster R-CNN model achieved an increase of 5.86% in mAP and 5.65% in F1-value. Consequently, the proposed method can be applied for the in-shell walnuts with shriveled and empty-shell defects.

Fragments dispersion characteristics of the casing with the mismatched shell under internal explosive loading

The shell of the conventional casings filled with explosives is often in a good matching state with the charged explosive, but the conventional casings cannot meet the needs of the design of innovative warheads. To further improve the control capability for fragment dispersion characteristics of fragment warheads, the concept of the casing with the mismatched shell is proposed and studied in this paper. This kind of casing is composed of a cylindrical explosive and an asymmetric shell. A typical casing with the mismatched shell is designed, and the fragment dispersion characteristics of the casing are experimentally obtained using X-ray radiography technology and witness target test technology. It is found that the flying direction of fragments from the casing is consistent with the normal direction of the shell, and the fragment dispersion density in a direction is significantly improved. The particular fragment dispersion characteristic of the casing is verified, and the effects of eccentric initiation and shell strength on the fragment dispersion characteristics of the casing are analyzed by numerical simulation. The numerical results show that the shell strength has little effect on the special fragment dispersion characteristics of this kind of charged casing. By controlling the position of the initiation point, the fragments in a specific direction can be concentrated to achieve the fragment directional killing. The findings herein could serve as a solid foundation for the engineering design of innovative fragment warheads and could also be a reference for the hazard assessment of Improvise Explosive Devices (IEDs).

Attenuation image referenced (AIR) effective atom number image calculation for MeV dual-energy container CT using image-domain deep learning framework

Traditional inspection technology for cargo or container imaging in customs and harbours is MeV X-ray radiography. The biggest limitation for this technology is the structural overlapping problem, which is inherent to radiography technology. MeV dual energy CT has a major advantage over radiography in that it can provide cross-section image, which is free of the structural overlapping problem. Besides, the recorded dual-energy projection data provides the ability for material decomposition. Electron density image and effective atom number image can be further calculated from the material decomposition coefficient images. However, the quality of effective atom number image can be very poor. The behind reasons are multifaceted. In this paper we proposed an Attenuation Image Referenced (AIR) effective atom number image calculation method for MeV dual-energy container CT imaging by using an image-domain neural network. The network has three channels as input and outputs with the estimated effective atom number image. The input three channels include the low and high-energy attenuation images and the effective atom number image that was directly calculated by using the derived formula. The network utilizes the low and high-energy attenuation image as guidance or reference for the restoration of effective atom number image. The network was trained on synthetic data, which is based on the shape of XCAT model but filled with materials that often appear in security imaging. The trained network also performed well on experimental data, showing the robustness and good generalization ability of the network. The quantitative analysis on the simulation and experimental data that comes from actual MeV dual-energy CT system showed the effectiveness of the proposed Attenuation Image Referenced (AIR) deep learning method for effective atom number image calculation.

Dental Radiographic/Digital Radiography Technology along with Biological Agents in Human Identification.

The heavy casualties associated with mass disasters necessitate substantial resources to be managed. The unexpectedly violent nature of such occurrences usually remains a problematic amount of victims that urgently require to be identified by a reliable and economical method. Conventional identification methods are inefficient in many cases such as plane crashes and fire accidents that have damaged the macrobiometric features such as fingerprints or faces. An appropriate recognition method for such cases should use features more resistant to destruction. Forensic dentistry provides the most appropriate available method for the successful identification of victims using careful techniques and precise data interpretation. Since bones and teeth are the most persistent parts of the demolished bodies in sudden mass disasters, scanning and radiographs are unrepeatable parts of forensic dentistry. Forensic dentistry as a scientific method of human remain identification has been considerably referred to be efficient in disasters. Forensic dentistry can be used for either “sex and age estimation,” “Medical biotechnology techniques,” or “identification with dental records,” etc. The present review is aimed at discussing the development and implementation of forensic dentistry methods for human identification. For this object, the literature from the last decade has been searched for the innovations in forensic dentistry for human identification based on the PubMed database.

Study on particle generation model of anode in rod-pinch diode

<sec>Flash radiography technology is commonly used in detonation physics experiments and nondestructive testing, in which an X-ray diode is an integral part of flash radiography equipment. Its function is to convert the electric energy stored in the front power supply into X-rays through the bremsstrahlung effect. Rod-pinch diode is one of the most commonly used X-ray diodes in 1–4 MV. It has the characteristics of a small focal spot and high imaging resolution. The anode ions of the rod pinch diode come from the anode plasma, and the anode plasma electrons are generated at the same time as the anode plasma ions. Before the establishment of the bipolar current between the anode and cathode of the rod pinch diode, these electrons are mainly absorbed by the anode; however, after the formation of the bipolar current, due to the zero electric field on the anode surface, plasma electrons will accumulate near the anode surface and will not be absorbed. Given the theoretical derivation of bipolar current in the gap between anode and cathode of rod pinch diode in the early stage, it is necessary to study the electrons in anode plasma.</sec><sec>The simulation of the rod-pinch diode is an essential tool for improving the performance of the rod-pinch diode. To improve simulation accuracy, it is necessary to study the emission mechanism of cathode and anode particles and continuously optimize the simulation model. In this paper, PIC and Monte Carlo simulation are used. An anode plasma model is proposed in this work based on the anode ion emission model of the rod-pinch diode and the characteristics of space charge bipolar flow, that is, when the anode plasma environment is fully established, the electric field on the anode surface is zero, and ions and electrons will accumulate on the anode surface. The new model is analyzed in detail and compared with the anode ion emission model in rod-pinch diode current, electromagnetic field distribution between cathode and anode, electron energy spectrum, motion state of electron incident anode rod, dose, and spot size. The results show that the calculation results from the new model are closer to the experimental results, which shows that the role of electrons accumulated near the anode in the plasma cannot be ignored in the numerical calculation of the rod-pinch diode anode rod surface plasma.</sec>

Applying Transfer Learning Using DenseNet121 in Radiographic Image Classification

The study aims to apply one of the fully connected convolutional neural networks, DenseNet121 network, to a data sample that includes a large group of radiographs through transfer learning technology. Radiography technology is a very important technique in the medical community to detect diseases and abnormalities that may be present, but the interpretation of these images may take a long time and it is subject to error by radiologists who are exposed to external practical factors (such as fatigue resulting from working for long hours, or exhaustion, or thinking about other life matters). To assist radiologists, we have worked on developing a diagnostic model with the help of a deep learning technique to classify radiographic images into two classes: (Normal and Abnormal images), by transferring the selected deep convolutional neural network between a large group of available networks that we studied on the basis of the regions that possibly abnormalities provided by the radiologists for the study sample. We also studied the feasibility of using the well-known VGG16 model on the same data sample and its performance through transfer learning technology and compared its results with the results of the DenseNet121 network. At the end of the research, we obtained a set of good results, which achieved a high diagnostic accuracy of 87.5% in some studied cases, using the DenseNet121 network model, which is considered satisfactory results in the case studied compared to the performance of other models. As for the VGG16 model, it did not give any of the satisfactory results in this field, the accuracy of the classification did not exceed 55% in most cases, and in only two cases it reached about 60% and 62%. The model presented during the research - DenseNet121 model - can be used in the diagnostic process and help in obtaining accurate results in terms of diagnostic results. As for the VGG16 model, it does not give satisfactory results according to the results also obtained during the research, so it is excluded in this type of applications.

Precise Diagnosis and Therapy of Bone Cancer Using Near-Infrared Lights.

Bone is a preferred site for both primary and metastasis tumors. Current diagnosis of osteopathia typically relies on noninvasive skeleton radiography technology. However, due to the limited resolution of ionizing radiation, accurate diagnosis and effective identification impairment areas are still lacking. Near-infrared (NIR) bioimaging, especially in the NIR-II (1000-1700 nm) regions, can provide high sensitivity and spatiotemporal resolution bioimaging compared to the conventional radiography. Thus, NIR bioimaging affords intraoperative visualization and imaging-guided surgery, aiming to overcome challenges associated with theranostics of osteopathia and bone tumors. The present review aimed to summarize the latest evidence on the use of NIR probes for the targeting bone imaging. We further highlight the recent advances in bone photoX (X presents thermal, dynamic, and immuno) therapy through NIR probes, in particular combination with other customized therapeutic agents could provide high-efficiency treatment for bone tumors.

Evaluation of Diagnostic Radiography Technology Curriculum from the Graduates Perspective

The purpose of this study is to evaluate the curriculum of diagnostic radiology technology for a bachelor degree considering the perspectives of graduates in Sudan. Exploring the graduate’s perspective would help to know about rapid development required in the field of diagnostic radiography technology in this era, along with important suggestions for the curriculum development. The quantitative study designed is employed, and a survey of 139 Diagnostic Radiologic Technologists (DRTs) having up to date curriculum, was performed. The collected data have been evaluated using SPSS version 23.0. Descriptive and inferential statistics were computed for the collected data. The results of this investigation showed that more than half of the participants i.e., 54.7% said that curriculum which they had studied in BSc of radiography keeps pace with rapid development in the field. 26.6% of the respondents suggested that curriculum needs some review to increase training hours in modern imaging modalities such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT) and Ultrasound (U/S). The study concludes that increasing the training time and integration of students when planning curriculum can improve students’ competence in relation to diagnostic radiography technology. The integration of the curriculum review practices increases service quality to ensure safe practice.

White spots noise removal of neutron images using improved robust principal component analysis

• A simple white spots removal method is proposed for degraded neutron images. • A‘detection-location-removal’ iterative strategy is introduced for the white spots detection and removal. • The qualitative and quantitative analysis are used for evaluating the performance of the mentioned methods. • The proposed method has a better performance in spots removal and details preservation than the comparison methods. Neutron radiography (NR) technology has been widely used in non-destructive investigations. However, the neutron images are always polluted by random white spots due to the interactions between the gamma rays, scattered neutron and other radiation and chip of the charge-coupled device (CCD) camera. In this paper, we propose a novel denoising method based on a ‘detection-location-removal’ iterative strategy, which adopts an improved robust principal component analysis (RPCA) in combination with the suitable threshold selection strategy and median filters for white spots noise removal of neutron images. Experimental results based on both simulation testing and real neutron images show that the proposed method is effective in improving neutron image quality in terms of numerical criteria and visual results. The comparison with the other denoising methods shows that the proposed method possesses higher robustness and effectiveness in practical denoising applications.

Combustion characteristics of solid propellants under high-temperature dense-particle erosion conditions

High-concentration alumina particle jet can erode the surface of the solid propellant inside a solid rocket motor under some special conditions such as flight acceleration. Because of lack of effective testing methods, knowledge of the combustion characteristics of solid propellants under dense-particle erosion conditions is very limited. In this study, the combustion characteristics of hydroxyl‑terminated polybutadiene and nitrate ester plasticized polyether propellants were investigated using real-time X-ray radiography technology and an overload simulation erosion motor. The high-temperature dense-particle jet can cause erosive burning of the solid propellants. No clear threshold velocity is found for the particle erosive burning, and the erosive burning rate increases with the particle velocity. The erosion of the dense-particle jet includes the heat flux increment effect and mechanical damage effect, and the particle erosive burning is mainly caused by the heat flux increment effect of the particles. Numerical simulation results show that the particles can impact the propellant surface at a very low speed and cause heat flux increments; this explains the lack of a clear threshold velocity for the particle erosive burning of solid propellants.

Feasibility Study of Phosphor Screen Containing Nano-Scale Anti-Reflection Layer for Improved Optical Properties in Indirect X-ray Detector.

With increasingly strict regulations regarding patient exposure, research on digital radiography technology has recently focused on indirect methods that can produce high-quality images for a low radiation dose. In particular, medical imaging systems based on indirect methods universally use rare-earth metal phosphors, because of their high atomic number and excellent luminescence efficiency. Thus, various studies aiming to improve the luminescence efficiency of phosphors have been conducted. Despite this research, however, the current luminescence efficiencies are insufficient. Here, we report a basic study aiming to develop a phosphor screen containing a three-quarter-wave optical-thickness layer to improve the light transmission efficiency. Specifically, the fabrication and measurement of a Gd2O2S:Tb phosphor screen containing a single three-quarter-wave optical-thickness layer is presented. The screen is fabricated via a screen-printing and spin-coating method. Based on histograms of the degree of luminescence and the pixel values, we demonstrate that the light transmission efficiency is improved by the three-quarter-wave optical-thickness layer. Note that analysis of the full width at half maximum of the pixel value distribution reveals the possibility of resolution loss when obtaining medical images. Overall, the results of this study confirm that the light transmission efficiency can be improved through use of a single-layer anti-reflection coating. However, because the emission spectrum of the Gd2O2S:Tb screen is in the 480-600-nm band, it is necessary to expand the areas exhibiting the lowest reflectance to the wavelengths at the edge of this band. Thus, further study should be conducted to optimize the optical thickness.