Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An a...Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.展开更多
Objective: to analyze the clinical effect of Digital Radiography in pulmonary examination for the elderly. Methods: A total of 118 elderly people who underwent pulmonary examination in our hospital from February 2019 ...Objective: to analyze the clinical effect of Digital Radiography in pulmonary examination for the elderly. Methods: A total of 118 elderly people who underwent pulmonary examination in our hospital from February 2019 to August 2020 were selected as the research subjects. The elderly were given DR and ordinary X-ray technology for pulmonary examination respectively. Those who underwent physical examination with DR were set as the observation group, and those who underwent physical examination by ordinary X-ray photography were set as control group. The speed and time of photography, the rate of grade A and the rate of disease detection in the two groups were observed and analyzed. Results: compared with the control group, the photography speed of observation group was significantly faster and the photography time was significantly shorter (P < 0.05). The grade A rate of observation group was significantly higher than that of control group (P < 0.05). The disease detection rate of observation group was significantly higher than that of control group (P < 0.05). Conclusion: the application of DR in the elderly pulmonary examination is better, the speed of photography is faster, the time is shorter, and the grade A rate and the disease detection rate are higher.展开更多
A high energy X-ray digital radiography(DR)nondestructive testing(NDT)system has been developed to detect the operating state of a driving mechanism.The system consists of five main subsystems,namely,X-ray generator,i...A high energy X-ray digital radiography(DR)nondestructive testing(NDT)system has been developed to detect the operating state of a driving mechanism.The system consists of five main subsystems,namely,X-ray generator,image intensifier,image processor,mechanical platform and control subsystem.Owning to the mechanical platform,the X-ray generator and image intensifier are able to rotate around the vertical axis from 0°to 360°in 35 s and move along vertical axis within the range of 500 mm in 20 s.The 450 kV X-ray generator provides a maximum 100 mm penetration depth and a coverage angle of 40°,and the resolution of the scanned image is 66 lp/cm.As is indicated by its applications,the system is featured with fast scanning speed,wide detection range and high imaging quality.It can be applied to inspect the defects in the driving mechanism as well.展开更多
The dental imaging department may come into contact with patients' oral secretions when taking digital dental radiographs, panoramic radiographs, dental CBCT and spiral CT, especially the digital dental radiograph...The dental imaging department may come into contact with patients' oral secretions when taking digital dental radiographs, panoramic radiographs, dental CBCT and spiral CT, especially the digital dental radiographs. At present, most dental medical institutions, such as stomatology departments of general hospitals, specialized stomatological hospitals and dental clinics, still use patients' fingers to press film or IP plate for photography, which brings the risk of cross-infection to the medical staff and patients, and brings severe challenges to the hospital feeling in dental photography. However, digital dental radiography is an essential examination item in clinical practice, such as dental trauma, dental pulp disease, periodontal disease and implant review, etc. The film holder is a digital dental film shooting auxiliary device, which can replace the patient's finger pressing film or IP board. Therefore, combined with clinical needs, it is particularly important to optimize the shooting process of digital dental film based on the use of film holder. It can not only meet the needs of clinical diagnosis and treatment, but also reduce the risk of cross infection to a great extent.展开更多
Accurate 3-dimensional(3-D)reconstruction technology for nondestructive testing based on digital radiography(DR)is of great importance for alleviating the drawbacks of the existing computed tomography(CT)-based method...Accurate 3-dimensional(3-D)reconstruction technology for nondestructive testing based on digital radiography(DR)is of great importance for alleviating the drawbacks of the existing computed tomography(CT)-based method.The commonly used Monte Carlo simulation method ensures well-performing imaging results for DR.However,for 3-D reconstruction,it is limited by its high time consumption.To solve this problem,this study proposes a parallel computing method to accelerate Monte Carlo simulation for projection images with a parallel interface and a specific DR application.The images are utilized for 3-D reconstruction of the test model.We verify the accuracy of parallel computing for DR and evaluate the performance of two parallel computing modes-multithreaded applications(G4-MT)and message-passing interfaces(G4-MPI)-by assessing parallel speedup and efficiency.This study explores the scalability of the hybrid G4-MPI and G4-MT modes.The results show that the two parallel computing modes can significantly reduce the Monte Carlo simulation time because the parallel speedup increment of Monte Carlo simulations can be considered linear growth,and the parallel efficiency is maintained at a high level.The hybrid mode has strong scalability,as the overall run time of the 180 simulations using 320 threads is 15.35 h with 10 billion particles emitted,and the parallel speedup can be up to 151.36.The 3-D reconstruction of the model is achieved based on the filtered back projection(FBP)algorithm using 180 projection images obtained with the hybrid G4-MPI and G4-MT.The quality of the reconstructed sliced images is satisfactory because the images can reflect the internal structure of the test model.This method is applied to a complex model,and the quality of the reconstructed images is evaluated.展开更多
Objective: The aim of the study was to investigate the efficacy of digital radiography(DR), computed tomography(CT) and magnetic resonance imaging(MRI) in bone tumors. Methods: Fifty-five patients with histologically ...Objective: The aim of the study was to investigate the efficacy of digital radiography(DR), computed tomography(CT) and magnetic resonance imaging(MRI) in bone tumors. Methods: Fifty-five patients with histologically confirmed bone tumors underwent imaging examinations. Fifty-five patients were performed DR, 21 CT and 20 MRI. Results: DR of 51 patients clearly revealed bone changes. DR of 40 patients well showed marginal. Twenty tumors appeared periosteal reaction on DR and 19 calcification on DR. CT scan of 21 patients clearly depicted bone changes, marginal and calcification and CT scan of 8 revealed periosteal reaction. MRI scan of 20 patients all showed marginal and soft-tissue mass and bone marrow edema was prominent in 8 patients. Conclusion: DR is the first imaging approach for born tumors. CT well reveal the extent and minute structure of the bone tumors, the extent, soft-tissue mass and bone marrow edema are more dramatically demonstrated on MRI imaging. DR integrates with CT and MRI, is helpful in diagnosis of bone tumors.展开更多
Currently, the diagnosis of tuberculosis (TB) is mainly based on the comprehensive consideration of the patient’s symptoms and signs, laboratory examinations and chest radiography (CXR). CXR plays a pivotal role to s...Currently, the diagnosis of tuberculosis (TB) is mainly based on the comprehensive consideration of the patient’s symptoms and signs, laboratory examinations and chest radiography (CXR). CXR plays a pivotal role to support the early diagnosis of TB, especially when used for TB screening and differential diagnosis. However, high cost of CXR hardware and shortage of certified radiologists poses a major challenge for CXR application in TB screening in resource limited settings. The latest development of artificial intelligence (AI) combined with the accumulation of a large number of medical images provides new opportunities for the establishment of computer-aided detection (CAD) systems in the medical applications, especially in the era of deep learning (DL) technology. Several CAD solutions are now commercially available and there is growing evidence demonstrate their value in imaging diagnosis. Recently, WHO published a rapid communication which stated that CAD may be used as an alternative to human reader interpretation of plain digital CXRs for screening and triage of TB.展开更多
Objective To assess collimation practices and quantify the irradiated area outside the area of diagnostic interest(ADI).Methods 1503 radiographs(627 females and 876 males)of seven body regions for patients with age gr...Objective To assess collimation practices and quantify the irradiated area outside the area of diagnostic interest(ADI).Methods 1503 radiographs(627 females and 876 males)of seven body regions for patients with age groups(≤1 year,1–12 years,13–17 years,18–65 years,≥65 years)from three major(A.governmental,B.university affiliated,and C.private)hospitals in northern Jordan were included.For each radiograph,the length and width of the irradiated area and of the ADI were measured.Then the ratio factors(RF),the irradiated area outside ADI,and the percentage of irradiated area outside ADI were calculated.Kruskal-Wallis and Mann-Whitney-U tests were used to examine the differences in ADI,the irradiated area outside ADI and RF according to age and gender.A regression analysis identified variables associated with RF and irradiated area outside ADI and its percentage.Results The RF ranged from 1.7 to 3.5.Patients aged≤1 year exhibited significantly higher irradiated area outside ADI(722.1cm^(2)),RF(3.7),and the percentage of irradiated area outside the ADI(72.7%)compared to other age groups(P<0.001).The actual collimation,area of ADI,and the irradiated area outside the ADI were significantly higher in males than those in females(P<0.001).Hospital A had a significantly higher irradiated area outside the ADI(871.4cm^(2)),RF(3.1),and percentage of irradiated area outside the ADI(67.2%)than other hospitals(P<0.001),which can be due to high patient volume in governmental hospitals and less time to pay attention to patient protection.Conclusions This study found inadequate X-ray beam collimation practice among radiographers in all participating hospitals,the radiation fields were at least two times larger than the ADI.This raises the importance of educating radiographers on collimation techniques and ensuring that all hospitals adhere to standardized collimation practices.展开更多
Digital chest radiography is a widely used modality for screening and diagnosing respiratory diseases.Within the Guangdong-Hong Kong-Macao Greater Bay Area,however,regional differences in equipment parameters,operatin...Digital chest radiography is a widely used modality for screening and diagnosing respiratory diseases.Within the Guangdong-Hong Kong-Macao Greater Bay Area,however,regional differences in equipment parameters,operating procedures,and radiation-protection standards have hindered medical collaboration,mutual recog-nition of results,and multicenter research.Meanwhile,although dynamic digital radiography(DDR)has been introduced into clinical practice,unified standards for image acquisition,functional evaluation,and radiation protection remain lacking.To address these challenges and promote high-quality integration of imaging services across the Greater Bay Area,there is an urgent need for a consensus that integrates both static and dynamic chest radiography while accommodating the regulatory frameworks and clinical practices of the three regions.The consensus establishes technical specifications,quality-control standards,and radiation-protection requirements applicable to both conventional and dynamic digital chest radiography.For the first time,it systematically in-tegrates DDR acquisition under quiet breathing,forced breathing,and blood-flow sequences;defines methods for functional parameter extraction and clinical application scenarios;and provides BMI-stratified exposure rec-ommendations with reference dose ranges.In addition,the consensus harmonizes relevant radiation-protection provisions from the Chinese Mainland,Hong Kong,China,and Macao,China,thereby forming a unified and actionable system for quality control and safety management.展开更多
Accurately identifying the location and type of internal defects in gas-insulated switchgear(GIS)is a challenge.To address this challenge,this study proposes a novel method for the nondestructive detection of GIS inte...Accurately identifying the location and type of internal defects in gas-insulated switchgear(GIS)is a challenge.To address this challenge,this study proposes a novel method for the nondestructive detection of GIS internal defects.This method is based on x-ray digital radiography(X-DR)technology and an improved real-time models for object detection(RTMdet)algorithm,namely GIS-specific localised internal defect-RTMdet.Firstly,the X-DR images of GIS are preprocessed by dynamic limit adaptive histogram equalisation algorithm to improve the images contrast.Then,a convolution shuffle upsample module for upsampling is proposed,which enlarges the defect feature map by multi-convolution and pixel shuffling,reduces the information loss,and enhances the interaction between the feature information.Finally,both the multi-channel attention net and the global attention mechanism are integrated into the neck network for enhancing local feature extraction and global information association.Experiments demonstrate that the pro-posed method achieves a mean average precision@0.5:0.95 of 94.9%,showcasing excellent overall performance and generalisation ability,and is more suitable for accurate nondestructive detection of internal defects of GIS in complex scenarios.展开更多
Gas–solid fluidized beds have historically been employed in a variety of fields owing to the excellent mixing they provide,which can enhance chemical reaction rates and make the control of the reactor temperature eas...Gas–solid fluidized beds have historically been employed in a variety of fields owing to the excellent mixing they provide,which can enhance chemical reaction rates and make the control of the reactor temperature easier than other technologies.Due to this wide application,heuristic knowledge of their functioning has been accumulating over the years.This knowledge,however,is not always backed by a deep understanding of the physical phenomena occurring in such systems.While this heuristic knowledge is sufficient to operate fluidized beds,operation optimization and scale-up are much harder to perform.A range of diagnostic techniques have been applied over the years to draw information about the inner workings of fluidized beds.Among these,x-ray imaging techniques,especially x-ray digital radiography and x-ray computed tomography,stand out for the kind and quality of information they can provide.Their high penetrating power enables visualization of phenomena taking place in the bulk of a fluidized bed,without disturbing the bed hydrodynamics.Furthermore,x rays are generated by a source that can be switched off,making them inherently safer than other imaging techniques relying on radioactive sources,such asγ-ray computed tomography.This work gives an overview of the techniques themselves,of the quantities they can measure,and of some modern applications of gas–solid fluidized beds they have been applied to,such as waste treatment and thermochemical conversion of biomass.Overall,x-ray digital radiography and x-ray computed tomography are better suited for process understanding than for process monitoring and are extremely useful in the study of voidage distribution and macro structures,such as bubbles and jets.展开更多
his paper presents a special container scanner in which the radiation source is a conventional radiography 60 Co projector of (100 300)×3 7×10 10 Bq. With a special sensitive array detector, i...his paper presents a special container scanner in which the radiation source is a conventional radiography 60 Co projector of (100 300)×3 7×10 10 Bq. With a special sensitive array detector, invented by Institute of Nuclear Energy Technology (INET) of Tsinghua University and other technical innovations, the characteristics of the 60 Co scanner qualify it for use in container inspection. Its contrast indicator (CI) and image quality indicator (IQI) for 100 mm steel are equal to 0 7% and 2 5%, respectively, and the steel penetration (SP) is about 240 mm. The 60 Co container scanner is much more economical and more reliable than those scanners using an accelerator source. Also, its penetration ability is much better than that of an X ray machine scanner. This paper presents the system design, the main difficulties and their technical solutions, the inspection characteristics and the special features of the 60 Co scanner.展开更多
Background High-voltage analog X-ray examination is a main tool for pneumoconiosis,which is challenged by digital radiography （DR）.The tube voltage of DR chest films required for diagnosis and staging of pneumoconio...Background High-voltage analog X-ray examination is a main tool for pneumoconiosis,which is challenged by digital radiography （DR）.The tube voltage of DR chest films required for diagnosis and staging of pneumoconiosis is concerned technically.We investigated the influence of the tube voltage on chest X-ray DR image quality of patients exposed to occupational dust.Methods DR images of the CDRAD2.0model,an anatomical chest phantom,and 136 exposed workers were analyzed at different tube voltages by threereaders.Image quality factors （IQF） were calculated and compared using the CDRAD2.0 model.DR images of ten anatomic positions were scored against those of the high-kilovolt chest films in anatomical phantom and clinical cases,and differences in scores were analyzed.Results In the CDRAD2.0 model,all three readers had a minimal IQF at 120 kV （mean：22.25 kV）.The differences in the mean IQF of DR images at different tube voltages was significant （F=13.78,P〈0.001）.The IQF of DR imaging at 120 kV was similar to high kilovolt analog imaging （t=-0.58,P〉0.05）.In the anatomic phantom and clinical cases,the DR images at 120 kV were closest in anatomical detail to the high W analog images,and the means were similar （P〉0.05）.Conclusions Among different tube voltages,DR image quality is closest to the high kilovolt analog images at 120 kV in patients exposed to occupational dust.展开更多
文摘Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.
文摘Objective: to analyze the clinical effect of Digital Radiography in pulmonary examination for the elderly. Methods: A total of 118 elderly people who underwent pulmonary examination in our hospital from February 2019 to August 2020 were selected as the research subjects. The elderly were given DR and ordinary X-ray technology for pulmonary examination respectively. Those who underwent physical examination with DR were set as the observation group, and those who underwent physical examination by ordinary X-ray photography were set as control group. The speed and time of photography, the rate of grade A and the rate of disease detection in the two groups were observed and analyzed. Results: compared with the control group, the photography speed of observation group was significantly faster and the photography time was significantly shorter (P < 0.05). The grade A rate of observation group was significantly higher than that of control group (P < 0.05). The disease detection rate of observation group was significantly higher than that of control group (P < 0.05). Conclusion: the application of DR in the elderly pulmonary examination is better, the speed of photography is faster, the time is shorter, and the grade A rate and the disease detection rate are higher.
文摘A high energy X-ray digital radiography(DR)nondestructive testing(NDT)system has been developed to detect the operating state of a driving mechanism.The system consists of five main subsystems,namely,X-ray generator,image intensifier,image processor,mechanical platform and control subsystem.Owning to the mechanical platform,the X-ray generator and image intensifier are able to rotate around the vertical axis from 0°to 360°in 35 s and move along vertical axis within the range of 500 mm in 20 s.The 450 kV X-ray generator provides a maximum 100 mm penetration depth and a coverage angle of 40°,and the resolution of the scanned image is 66 lp/cm.As is indicated by its applications,the system is featured with fast scanning speed,wide detection range and high imaging quality.It can be applied to inspect the defects in the driving mechanism as well.
文摘The dental imaging department may come into contact with patients' oral secretions when taking digital dental radiographs, panoramic radiographs, dental CBCT and spiral CT, especially the digital dental radiographs. At present, most dental medical institutions, such as stomatology departments of general hospitals, specialized stomatological hospitals and dental clinics, still use patients' fingers to press film or IP plate for photography, which brings the risk of cross-infection to the medical staff and patients, and brings severe challenges to the hospital feeling in dental photography. However, digital dental radiography is an essential examination item in clinical practice, such as dental trauma, dental pulp disease, periodontal disease and implant review, etc. The film holder is a digital dental film shooting auxiliary device, which can replace the patient's finger pressing film or IP board. Therefore, combined with clinical needs, it is particularly important to optimize the shooting process of digital dental film based on the use of film holder. It can not only meet the needs of clinical diagnosis and treatment, but also reduce the risk of cross infection to a great extent.
基金the China Natural Science Fund(No.52171253)the Natural Science Foundation of Sichuan(No.2022NSFSCO949).
文摘Accurate 3-dimensional(3-D)reconstruction technology for nondestructive testing based on digital radiography(DR)is of great importance for alleviating the drawbacks of the existing computed tomography(CT)-based method.The commonly used Monte Carlo simulation method ensures well-performing imaging results for DR.However,for 3-D reconstruction,it is limited by its high time consumption.To solve this problem,this study proposes a parallel computing method to accelerate Monte Carlo simulation for projection images with a parallel interface and a specific DR application.The images are utilized for 3-D reconstruction of the test model.We verify the accuracy of parallel computing for DR and evaluate the performance of two parallel computing modes-multithreaded applications(G4-MT)and message-passing interfaces(G4-MPI)-by assessing parallel speedup and efficiency.This study explores the scalability of the hybrid G4-MPI and G4-MT modes.The results show that the two parallel computing modes can significantly reduce the Monte Carlo simulation time because the parallel speedup increment of Monte Carlo simulations can be considered linear growth,and the parallel efficiency is maintained at a high level.The hybrid mode has strong scalability,as the overall run time of the 180 simulations using 320 threads is 15.35 h with 10 billion particles emitted,and the parallel speedup can be up to 151.36.The 3-D reconstruction of the model is achieved based on the filtered back projection(FBP)algorithm using 180 projection images obtained with the hybrid G4-MPI and G4-MT.The quality of the reconstructed sliced images is satisfactory because the images can reflect the internal structure of the test model.This method is applied to a complex model,and the quality of the reconstructed images is evaluated.
文摘Objective: The aim of the study was to investigate the efficacy of digital radiography(DR), computed tomography(CT) and magnetic resonance imaging(MRI) in bone tumors. Methods: Fifty-five patients with histologically confirmed bone tumors underwent imaging examinations. Fifty-five patients were performed DR, 21 CT and 20 MRI. Results: DR of 51 patients clearly revealed bone changes. DR of 40 patients well showed marginal. Twenty tumors appeared periosteal reaction on DR and 19 calcification on DR. CT scan of 21 patients clearly depicted bone changes, marginal and calcification and CT scan of 8 revealed periosteal reaction. MRI scan of 20 patients all showed marginal and soft-tissue mass and bone marrow edema was prominent in 8 patients. Conclusion: DR is the first imaging approach for born tumors. CT well reveal the extent and minute structure of the bone tumors, the extent, soft-tissue mass and bone marrow edema are more dramatically demonstrated on MRI imaging. DR integrates with CT and MRI, is helpful in diagnosis of bone tumors.
基金National Science and Technology Major Project of China(2017ZX10201302-008)。
文摘Currently, the diagnosis of tuberculosis (TB) is mainly based on the comprehensive consideration of the patient’s symptoms and signs, laboratory examinations and chest radiography (CXR). CXR plays a pivotal role to support the early diagnosis of TB, especially when used for TB screening and differential diagnosis. However, high cost of CXR hardware and shortage of certified radiologists poses a major challenge for CXR application in TB screening in resource limited settings. The latest development of artificial intelligence (AI) combined with the accumulation of a large number of medical images provides new opportunities for the establishment of computer-aided detection (CAD) systems in the medical applications, especially in the era of deep learning (DL) technology. Several CAD solutions are now commercially available and there is growing evidence demonstrate their value in imaging diagnosis. Recently, WHO published a rapid communication which stated that CAD may be used as an alternative to human reader interpretation of plain digital CXRs for screening and triage of TB.
基金funding by Jordan University of Science and Technology Deanship of Research Grant numbers(No.20230465).
文摘Objective To assess collimation practices and quantify the irradiated area outside the area of diagnostic interest(ADI).Methods 1503 radiographs(627 females and 876 males)of seven body regions for patients with age groups(≤1 year,1–12 years,13–17 years,18–65 years,≥65 years)from three major(A.governmental,B.university affiliated,and C.private)hospitals in northern Jordan were included.For each radiograph,the length and width of the irradiated area and of the ADI were measured.Then the ratio factors(RF),the irradiated area outside ADI,and the percentage of irradiated area outside ADI were calculated.Kruskal-Wallis and Mann-Whitney-U tests were used to examine the differences in ADI,the irradiated area outside ADI and RF according to age and gender.A regression analysis identified variables associated with RF and irradiated area outside ADI and its percentage.Results The RF ranged from 1.7 to 3.5.Patients aged≤1 year exhibited significantly higher irradiated area outside ADI(722.1cm^(2)),RF(3.7),and the percentage of irradiated area outside the ADI(72.7%)compared to other age groups(P<0.001).The actual collimation,area of ADI,and the irradiated area outside the ADI were significantly higher in males than those in females(P<0.001).Hospital A had a significantly higher irradiated area outside the ADI(871.4cm^(2)),RF(3.1),and percentage of irradiated area outside the ADI(67.2%)than other hospitals(P<0.001),which can be due to high patient volume in governmental hospitals and less time to pay attention to patient protection.Conclusions This study found inadequate X-ray beam collimation practice among radiographers in all participating hospitals,the radiation fields were at least two times larger than the ADI.This raises the importance of educating radiographers on collimation techniques and ensuring that all hospitals adhere to standardized collimation practices.
文摘Digital chest radiography is a widely used modality for screening and diagnosing respiratory diseases.Within the Guangdong-Hong Kong-Macao Greater Bay Area,however,regional differences in equipment parameters,operating procedures,and radiation-protection standards have hindered medical collaboration,mutual recog-nition of results,and multicenter research.Meanwhile,although dynamic digital radiography(DDR)has been introduced into clinical practice,unified standards for image acquisition,functional evaluation,and radiation protection remain lacking.To address these challenges and promote high-quality integration of imaging services across the Greater Bay Area,there is an urgent need for a consensus that integrates both static and dynamic chest radiography while accommodating the regulatory frameworks and clinical practices of the three regions.The consensus establishes technical specifications,quality-control standards,and radiation-protection requirements applicable to both conventional and dynamic digital chest radiography.For the first time,it systematically in-tegrates DDR acquisition under quiet breathing,forced breathing,and blood-flow sequences;defines methods for functional parameter extraction and clinical application scenarios;and provides BMI-stratified exposure rec-ommendations with reference dose ranges.In addition,the consensus harmonizes relevant radiation-protection provisions from the Chinese Mainland,Hong Kong,China,and Macao,China,thereby forming a unified and actionable system for quality control and safety management.
基金National Engineering Research Center of UHV Technology and New Electrical Equipment Basis of China Southern Power Grid Research Institute Co.,Ltd,Grant/Award Number:NERCUTNEEB-2022-KF-08。
文摘Accurately identifying the location and type of internal defects in gas-insulated switchgear(GIS)is a challenge.To address this challenge,this study proposes a novel method for the nondestructive detection of GIS internal defects.This method is based on x-ray digital radiography(X-DR)technology and an improved real-time models for object detection(RTMdet)algorithm,namely GIS-specific localised internal defect-RTMdet.Firstly,the X-DR images of GIS are preprocessed by dynamic limit adaptive histogram equalisation algorithm to improve the images contrast.Then,a convolution shuffle upsample module for upsampling is proposed,which enlarges the defect feature map by multi-convolution and pixel shuffling,reduces the information loss,and enhances the interaction between the feature information.Finally,both the multi-channel attention net and the global attention mechanism are integrated into the neck network for enhancing local feature extraction and global information association.Experiments demonstrate that the pro-posed method achieves a mean average precision@0.5:0.95 of 94.9%,showcasing excellent overall performance and generalisation ability,and is more suitable for accurate nondestructive detection of internal defects of GIS in complex scenarios.
文摘Gas–solid fluidized beds have historically been employed in a variety of fields owing to the excellent mixing they provide,which can enhance chemical reaction rates and make the control of the reactor temperature easier than other technologies.Due to this wide application,heuristic knowledge of their functioning has been accumulating over the years.This knowledge,however,is not always backed by a deep understanding of the physical phenomena occurring in such systems.While this heuristic knowledge is sufficient to operate fluidized beds,operation optimization and scale-up are much harder to perform.A range of diagnostic techniques have been applied over the years to draw information about the inner workings of fluidized beds.Among these,x-ray imaging techniques,especially x-ray digital radiography and x-ray computed tomography,stand out for the kind and quality of information they can provide.Their high penetrating power enables visualization of phenomena taking place in the bulk of a fluidized bed,without disturbing the bed hydrodynamics.Furthermore,x rays are generated by a source that can be switched off,making them inherently safer than other imaging techniques relying on radioactive sources,such asγ-ray computed tomography.This work gives an overview of the techniques themselves,of the quantities they can measure,and of some modern applications of gas–solid fluidized beds they have been applied to,such as waste treatment and thermochemical conversion of biomass.Overall,x-ray digital radiography and x-ray computed tomography are better suited for process understanding than for process monitoring and are extremely useful in the study of voidage distribution and macro structures,such as bubbles and jets.
文摘his paper presents a special container scanner in which the radiation source is a conventional radiography 60 Co projector of (100 300)×3 7×10 10 Bq. With a special sensitive array detector, invented by Institute of Nuclear Energy Technology (INET) of Tsinghua University and other technical innovations, the characteristics of the 60 Co scanner qualify it for use in container inspection. Its contrast indicator (CI) and image quality indicator (IQI) for 100 mm steel are equal to 0 7% and 2 5%, respectively, and the steel penetration (SP) is about 240 mm. The 60 Co container scanner is much more economical and more reliable than those scanners using an accelerator source. Also, its penetration ability is much better than that of an X ray machine scanner. This paper presents the system design, the main difficulties and their technical solutions, the inspection characteristics and the special features of the 60 Co scanner.
文摘Background High-voltage analog X-ray examination is a main tool for pneumoconiosis,which is challenged by digital radiography （DR）.The tube voltage of DR chest films required for diagnosis and staging of pneumoconiosis is concerned technically.We investigated the influence of the tube voltage on chest X-ray DR image quality of patients exposed to occupational dust.Methods DR images of the CDRAD2.0model,an anatomical chest phantom,and 136 exposed workers were analyzed at different tube voltages by threereaders.Image quality factors （IQF） were calculated and compared using the CDRAD2.0 model.DR images of ten anatomic positions were scored against those of the high-kilovolt chest films in anatomical phantom and clinical cases,and differences in scores were analyzed.Results In the CDRAD2.0 model,all three readers had a minimal IQF at 120 kV （mean：22.25 kV）.The differences in the mean IQF of DR images at different tube voltages was significant （F=13.78,P〈0.001）.The IQF of DR imaging at 120 kV was similar to high kilovolt analog imaging （t=-0.58,P〉0.05）.In the anatomic phantom and clinical cases,the DR images at 120 kV were closest in anatomical detail to the high W analog images,and the means were similar （P〉0.05）.Conclusions Among different tube voltages,DR image quality is closest to the high kilovolt analog images at 120 kV in patients exposed to occupational dust.
