In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate ...In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.展开更多
Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for ...Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for laser plasma diagnostics was achieved using a developed toroidal crystal x-ray imager.A high-index crystal orientation Ge(531)wafer with a Bragg angle of 75.37°and the toroidal substrate were selected to obtain sufficient diffraction efficiency and compensate for astigmatism under oblique incidence.A precise offline assembly method of the toroidal crystal imager based on energy substitution was proposed,and a spatial resolution of 3-7μm was obtained by toroidal crystal imaging of a 600 line-pairs/inch Au grid within an object field of view larger than 1.0 mm.The toroidal crystal x-ray imager has been successfully tested via side-on backlight imaging experiments of the sinusoidal modulation target and a 1000 line-pairs/inch Au grid with a linewidth of 5μm using an online alignment method based on dual positioning balls to indicate the target and backlighter.This paper describes the optical design,adjustment method,and experimental results of a toroidal crystal system in a laboratory and laser facility.展开更多
BACKGROUND Pleural effusions occur for various reasons,and their diagnosis remains challenging despite the availability of different diagnostic modalities.Medical thoracoscopy(MT)can be used for both diagnostic and th...BACKGROUND Pleural effusions occur for various reasons,and their diagnosis remains challenging despite the availability of different diagnostic modalities.Medical thoracoscopy(MT)can be used for both diagnostic and therapeutic purposes,especially in patients with undiagnosed pleural effusion.AIM To assess the diagnostic efficacy and safety of MT in patients with pleural effusion of different causes.METHODS Between January 1,2012 and April 30,2021,patients with pleural effusion underwent MT in the Department of Respiratory Medicine,The Second Affiliated Hospital of Xi’an Jiaotong University(Shaanxi,China).According to the discharge diagnosis,patients were divided into malignant pleural effusion(MPE),tuberculous pleural effusion(TBPE),and inflammatory pleural effusion(IPE)groups.General information,and tuberculosis-and effusion-related indices of the three groups were analyzed.The diagnostic yield,diagnostic accuracy,performance under thoracoscopy,and complications of patients were compared among the three groups.Then,the significant predictive factors for diagnosis between the MPE and TBPE groups were analyzed.RESULTS Of the 106 patients enrolled in this 10-year study,67 were male and 39 female,with mean age of 57.1±14.184 years.Among the 74 thoracoscopy-confirmed patients,41(38.7%)had MPE,21 had(19.8%)TBPE,and 32(30.2%)were undiagnosed.Overall diagnostic yield of MT was 69.8%(MPE:75.9%,TBPE:48.8%,and IPE:75.0%,with diagnostic accuracies of 100%,87.5%,and 75.0%,respectively).Under thoracoscopy,single or multiple pleural nodules were observed in 81.1%and pleural adhesions in 34.0%with pleural effusions.The most common complication was chest pain(41.5%),followed by chest tightness(11.3%)and fever(10.4%).Multivariate logistic regression analyses showed effusion appearance[odds ratio(OR):0.001,95%CI:0.000-0.204;P=0.010]and carcinoembryonic antigen(OR:0.243,95%CI:0.081-0.728;P=0.011)as significant for differentiating MPE and TBPE,with area under the receiver operating characteristic curve of 0.977(95%CI:0.953-1.000;P<0.001).CONCLUSION MT is an effective,safe,and minimally invasive procedure with high diagnostic yield for pleural effusion of different causes.展开更多
In this paper, the development of smart medical autonomous technology is considered. An example of a smart medical autonomous distributed system for diagnostics is also discussed. To develop this system for medical im...In this paper, the development of smart medical autonomous technology is considered. An example of a smart medical autonomous distributed system for diagnostics is also discussed. To develop this system for medical image analysis we review several processing methods. The use of the cuneiform dehydration method for medical diagnosis is considered. The experimental results obtained for blood serum dehydrated films are presented. The author proposes an algorithm for the primary identification of structures formed in the films and their use for automated detection of various structures for diagnostic purposes. The paper describes the first stage of image processing, i.e. the selection of filtering types for the correct identification of structural features and characteristics of the images. The results of filtering and some computational results of various types of structures in the films are presented.展开更多
The hepatitis B virus is the most deadly virus,which significantly affects the human liver.The termination of the hepatitis B virus is mandatory and can be done by taking precautions as well as a suitable cure in its ...The hepatitis B virus is the most deadly virus,which significantly affects the human liver.The termination of the hepatitis B virus is mandatory and can be done by taking precautions as well as a suitable cure in its introductory stage;otherwise,it will become a severe problem and make a human liver suffer from the most dangerous diseases,such as liver cancer.In this paper,two medical diagnostic systems are developed for the diagnosis of this life-threatening virus.The methodologies used to develop thesemodels are fuzzy logic and the neuro-fuzzy technique.The diverse parameters that assist in the evaluation of performance are also determined by using the observed values from the proposed system for both developedmodels.The classification accuracy of a multilayered fuzzy inference system is 94%.The accuracy with which the developed medical diagnostic system by using Adaptive Network based Fuzzy Interference System(ANFIS)classifies the result corresponding to the given input is 95.55%.The comparison of both developed models on the basis of their performance parameters has been made.It is observed that the neuro-fuzzy technique-based diagnostic system has better accuracy in classifying the infected and non-infected patients as compared to the fuzzy diagnostic system.Furthermore,the performance evaluation concluded that the outcome given by the developed medical diagnostic system by using ANFIS is accurate and correct as compared to the developed fuzzy inference system and also can be used in hospitals for the diagnosis of Hepatitis B disease.In other words,the adaptive neuro-fuzzy inference system has more capability to classify the provided inputs adequately than the fuzzy inference system.展开更多
Medical diagnostic tables are widely used inthemedical diagnostic equipment. For multifarious diagnostic needs, the medical diagnostic table works in various operating modes. In order to ensure patient safety, safety ...Medical diagnostic tables are widely used inthemedical diagnostic equipment. For multifarious diagnostic needs, the medical diagnostic table works in various operating modes. In order to ensure patient safety, safety factor of medical diagnostic table must meet safety requirement. The paper puts forward a method to find relations between key parameters and stress of table, identify maximum stress modes, reduce modes number of load test, and remove conservative high stress areas from finite element analysis result, by synthesizingthestress result of finite element analysis and measurement data for various operating modes of medical diagnostic table. It will help shorten test time, avoid over strength design, and reduce table’s cost. An application example of the method is presented by evaluating a specific CT medical diagnostictable. This method can be a reference for safety evaluation of all medical diagnostic tables.展开更多
1 BackgroundIt is well known that the radiology diagnostic report as the essential component of the patient′s permanent health record,which radiography is an indispensable diagnostic tool.Our duties are observe the i...1 BackgroundIt is well known that the radiology diagnostic report as the essential component of the patient′s permanent health record,which radiography is an indispensable diagnostic tool.Our duties are observe the imaging carefully and write a展开更多
A diagnostic system of soft x-ray diode-array was set up for HT-7 superconducting tokamak. The system consists of two slot-aperture cameras and is capable of measuring the soft x-ray emission from the plasma on HT-7 d...A diagnostic system of soft x-ray diode-array was set up for HT-7 superconducting tokamak. The system consists of two slot-aperture cameras and is capable of measuring the soft x-ray emission from the plasma on HT-7 device with a high resolution in space and a high response in time. Both cameras, located separately in a horizontal port and a vertical port each with thirty-seven detectors of An-Si surface-barrier diode (SBD) can view the same toroidal cross-section of the plasma from different poloidal chords. In this paper, the structure, principle and performance of the diagnostic system are described and some experimental results observed are presented.展开更多
Currently,with the advent of high-repetition-rate laser-plasma experiments,the demand for online diagnosis for the X-ray spectrum is increasing because the laser-plasma-generated X-ray spectrum is very important for c...Currently,with the advent of high-repetition-rate laser-plasma experiments,the demand for online diagnosis for the X-ray spectrum is increasing because the laser-plasma-generated X-ray spectrum is very important for characterizing electron dynamics and applications.In this study,scintillators and silicon PIN(P-type–intrinsic-N-type semiconductor)diodes were used to construct a wideband online filter stack spectrometer.The X-ray sensor and filter arrangement was optimized using a genetic algorithm to minimize the condition number of the response matrix.Consequently,the unfolding error was significantly reduced based on numerical experiments.The detector responses were quantitatively calibrated by irradiating the scintillator and PIN diode with various nuclides and comparing the measuredγ-ray peaks.A prototype 15-channel spectrometer was developed by integrating an X-ray detector with front-and back-end electronics.The prototype spectrometer could record X-ray pulse signals at a repetition rate of 1 kHz.Furthermore,an optimized spectrometer was employed to record the real-time spectra of laser-driven bremsstrahlung sources.This optimized spectrometer offers a compact solution for spectrum diagnostics of ultrashort X-ray pulses,exhibiting improved accuracy in terms of spectrum measurements and repetition rates,and could be widely used in next-generation high-repetition-rate high-power laser facilities.展开更多
Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has a...Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.展开更多
X-Ray sources, detectors and optical components are now used in a wide range of applications. What is crucial is the absolute calibration of such devices to permit a quantitative assessment of the system under study. ...X-Ray sources, detectors and optical components are now used in a wide range of applications. What is crucial is the absolute calibration of such devices to permit a quantitative assessment of the system under study. A new X-ray laboratory has been built in Frascati (ENEA) to develop diagnostics for nuclear fusion experiments and study applications of these X-ray techniques in other domains, like new material science, non destructive tests and so on. An in-house developed selfconsistent calibration procedure is described that permits the absolute calibration of sources (X-ray emitted fluxes) and detectors (detection efficiencies) as function of the X-ray photon energy, in the range 2 - 120 keV. The calibration procedure involves the use of an in-house developed code that also predicts the spectral response of any detector in any experimental condition that can be setup in the laboratory. The procedure has been then applied for the calibration and characterisation of gas and solid state imaging detectors, such as Medipix-2, GEM gas detector, CCD camera, Cd-Te C-MOS imager, demonstrating the versatility of the method developed here.展开更多
Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease(IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentia...Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease(IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography(CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging(MRI) and small intestine contrast enhanced ultrasonography(SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn's disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT.展开更多
Diagnostic errors are important in all branches of medicine because they are an indication of poor patient care. Since the early 1970s,physicians have been subjected to an increasing number of medical malpractice clai...Diagnostic errors are important in all branches of medicine because they are an indication of poor patient care. Since the early 1970s,physicians have been subjected to an increasing number of medical malpractice claims. Radiology is one of the specialties most liable to claims of medical negligence.Most often,a plaintiff's complaint against a radiologist will focus on a failure to diagnose. The etiology of radiological error is multi-factorial.Errors fall into recurrent patterns.Errors arise from poor technique,failures of perception,lack of knowledge and misjudgments.The work of diagnostic radiology consists of the complete detection of all abnormalities in an imaging examination and their accurate diagnosis. Every radiologist should understand the sources of error in diagnostic radiology as well as the elements of negligence that form the basis of malpractice litigation.Error traps need to be uncovered and highlighted,in order to prevent repetition of the same mistakes.This article focuses on the spectrum of diagnostic errors in radiology, including a classification of the errors,and stresses the malpractice issues in mammography,chest radiology and obstetric sonography.Missed fractures in emergency and communication issues between radiologists and physicians are also discussed.展开更多
Effective medical diagnosis is dramatically expensive,especially in third-world countries.One of the common diseases is pneumonia,and because of the remarkable similarity between its types and the limited number of me...Effective medical diagnosis is dramatically expensive,especially in third-world countries.One of the common diseases is pneumonia,and because of the remarkable similarity between its types and the limited number of medical images for recent diseases related to pneumonia,themedical diagnosis of these diseases is a significant challenge.Hence,transfer learning represents a promising solution in transferring knowledge from generic tasks to specific tasks.Unfortunately,experimentation and utilization of different models of transfer learning do not achieve satisfactory results.In this study,we suggest the implementation of an automatic detectionmodel,namelyCADTra,to efficiently diagnose pneumonia-related diseases.This model is based on classification,denoising autoencoder,and transfer learning.Firstly,pre-processing is employed to prepare the medical images.It depends on an autoencoder denoising(AD)algorithm with a modified loss function depending on a Gaussian distribution for decoder output to maximize the chances for recovering inputs and clearly demonstrate their features,in order to improve the diagnosis process.Then,classification is performed using a transfer learning model and a four-layer convolution neural network(FCNN)to detect pneumonia.The proposed model supports binary classification of chest computed tomography(CT)images and multi-class classification of chest X-ray images.Finally,a comparative study is introduced for the classification performance with and without the denoising process.The proposed model achieves precisions of 98%and 99%for binary classification and multi-class classification,respectively,with the different ratios for training and testing.To demonstrate the efficiency and superiority of the proposed CADTra model,it is compared with some recent state-of-the-art CNN models.The achieved outcomes prove that the suggested model can help radiologists to detect pneumonia-related diseases and improve the diagnostic efficiency compared to the existing diagnosis models.展开更多
The unavailability of sufficient information for proper diagnosis,incomplete or miscommunication between patient and the clinician,or among the healthcare professionals,delay or incorrect diagnosis,the fatigue of clin...The unavailability of sufficient information for proper diagnosis,incomplete or miscommunication between patient and the clinician,or among the healthcare professionals,delay or incorrect diagnosis,the fatigue of clinician,or even the high diagnostic complexity in limited time can lead to diagnostic errors.Diagnostic errors have adverse effects on the treatment of a patient.Unnecessary treatments increase the medical bills and deteriorate the health of a patient.Such diagnostic errors that harm the patient in various ways could be minimized using machine learning.Machine learning algorithms could be used to diagnose various diseases with high accuracy.The use of machine learning could assist the doctors in making decisions on time,and could also be used as a second opinion or supporting tool.This study aims to provide a comprehensive review of research articles published from the year 2015 to mid of the year 2020 that have used machine learning for diagnosis of various diseases.We present the various machine learning algorithms used over the years to diagnose various diseases.The results of this study show the distribution of machine learning methods by medical disciplines.Based on our review,we present future research directions that could be used to conduct further research.展开更多
Background: Systematic chest X-ray is the most prescribed examination by occupational physicians during periodic medical check-ups in our context, unlike in most countries where this practice has been discontinued. Ob...Background: Systematic chest X-ray is the most prescribed examination by occupational physicians during periodic medical check-ups in our context, unlike in most countries where this practice has been discontinued. Objective: The objective was to determine the diagnostic yield and cost-effectiveness of chest radiography during periodic medical check-ups of workers in Ngaoundere. Materials and Methods: A cross-sectional and descriptive study was carried out in Ngaoundere Regional Hospital from January to December 2018, concerning all persons coming to perform a systematic chest X-ray in the context of the periodic medical check-up having been consented to participate in the study. Posteroanterior (PA) chest radiographs were obtained from all workers during this periodic medical check-up. The variables studied were: age, sex, clinical manifestations, antecedents, job type, cost, and chest X-ray results. Statistical analysis was performed using the Sphinx Plus2-Lexica-V5 Edition software. Results: 753 workers were selected for this study, of whom 88.04% were men and 11.96% were women, a sex ratio H/F is of 7.4, the average age was 39 ± 7.89 years with extremes of 24 and 56 years, the most frequent job type was the administration (38.37%), the storekeepers (17.92) and the drivers (15.27%), most of them were asymptomatic (97.47%), some had cough (2.52%), chest pain (2.12%), dyspnea (0.26%) and fever (0.13%). History was dominated by lung infection (2.39%), pleurisy (1.06%) and tuberculosis (0.79%). 7.43% of workers occasionally smoked tobacco and consumed alcohol. 41 cases of pathologies (5.44%) were found on the chest X-ray, including 1 case (0.13%) of evolutionary pathology, 40 cases (5.31%) of sequelae pathologies. When the results of the chest X-ray are compared with the clinical signs and the pathological history of the workers, it is found that the only case with evolutionary abnormalities on the chest X-ray showed clinical signs and that the other cases with sequelae abnormalities had either clinical signs or antecedents related to these abnormalities. The cost of a chest X-ray at the time of our study was 5,000 FCFA ($8.59), for a total of 3,765,000 FCFA ($6473.74) for all the X-rays performed. Conclusion: In view of the low rate of abnormalities on the chest X-ray and the sequelae nature of the pathologies, it can be said that the routine X-ray of the chest during the periodic medical check-ups has a low diagnostic yield and a low cost-effectiveness ratio and is not profitable. It should be non-systematic and case-by-case based on the clinical context and background of workers.展开更多
A novel real time fast electron bremsstrahlung (FEB) diagnostic system based on the lutetium yttrium oxyorthosilicate scintillators (LYSO) and silicon photomultipliers (SiPM) has been developed for tokamak.The diagnos...A novel real time fast electron bremsstrahlung (FEB) diagnostic system based on the lutetium yttrium oxyorthosilicate scintillators (LYSO) and silicon photomultipliers (SiPM) has been developed for tokamak.The diagnostic system is dedicated to study the FEB emission in the hard x-ray (HXR) energy range between 10 and 200 keV during the lower hybrid current drive.The system consists of a detection module and three data acquisition and processing (DAP)boards.The detection module consists of annulus LYSO-SiPM detector array and a 12-channel preamplifier module.The DAP boards upload the data to the host computer for displaying and storing through PXI bus.The time and space resolutions of the system are 10 ms and 4 cm,respectively.The experimental results can show the evolution over time and the spatial distribution of FEB.This paper presents the system performance and typical discharge results.展开更多
This research presents the results of investigation of laser_polarization fluorescence ofbiological layers(histological sections,cy tological smears)in the task of diagnostics and differ-en tiation of early stages of ...This research presents the results of investigation of laser_polarization fluorescence ofbiological layers(histological sections,cy tological smears)in the task of diagnostics and differ-en tiation of early stages of cancer:Dysplasia-cervical microinvasive carcinoma of cervic uteri.The analytical conditions of polarization-optimal probing of biological layers were determinedbasing on the model of linear birefringence and dichroism of birefringent(fibrllar,porphyrin)networks.The technique of polarization-variable laser autofluorescence was developed andexperimentally tested.The objective criteria(statistical moments)of differentiation of histo-logical sections autofluorescent images of endometrium biopsy and cytological smears of itmucous coat were defined.The operational characteristics(sensitivity,speifity,accuracy)ofthis technique were determined concerning the positions of probative medicine,and clinical efficiency.展开更多
Objectives: To assess the patients and health personnel’s level of awareness on risks related to ionizing radiation during CT scan. Materials and methods: Three questionnaires were addressed to patients, prescribing ...Objectives: To assess the patients and health personnel’s level of awareness on risks related to ionizing radiation during CT scan. Materials and methods: Three questionnaires were addressed to patients, prescribing physicians, and the medical imaging staff for three hospitals respectively. This permitted us to assess their knowledge on the benefits and risks of the required medical exam, based on the dangers of being exposed to X-rays, especially induced-radiation cancer following the amount of X-rays received during a CT scan and the possibility of not receiving radiation as tools of diagnosis. Results: 150 patients, 84 referring doctors of CT scan tests and 60 medical imaging personnel were retained. For patients, only 7.1% received information on the benefits and risks of their exams, and 34.4% believed that x-rays were harmful to their health. For the prescribers, 46.7% took into account the benefits/risk ratio before prescribing a test and only 16.7% of the referring doctors have informed the patient of the risks related to X-ray. 90% of the medical imaging staff ensures that the required test is justified, and 50% informed the patient on the risks associated with their radiation exposure, and the increased risk of developing cancer. 65% of the imaging staff could not estimate the dose that the patient will receive during the medical test. 25% mentioned the dose received during the acquisition in the patient’s exam report. Conclusion: This study confirms that the referring doctors, the patients, and the radiologists have a low knowledge concerning the risks associated with radiation exposure during a CT scan assessment. We will therefore say that patients and prescribers are not aware of the doses of radiation on CT and their possible risks, even though there is a risk of developing cancer.展开更多
文摘In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.
基金National Natural Science Foundation of China(No.11805212)National Key Research and Development Program of China(No.2019YFE03080200)。
文摘Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for laser plasma diagnostics was achieved using a developed toroidal crystal x-ray imager.A high-index crystal orientation Ge(531)wafer with a Bragg angle of 75.37°and the toroidal substrate were selected to obtain sufficient diffraction efficiency and compensate for astigmatism under oblique incidence.A precise offline assembly method of the toroidal crystal imager based on energy substitution was proposed,and a spatial resolution of 3-7μm was obtained by toroidal crystal imaging of a 600 line-pairs/inch Au grid within an object field of view larger than 1.0 mm.The toroidal crystal x-ray imager has been successfully tested via side-on backlight imaging experiments of the sinusoidal modulation target and a 1000 line-pairs/inch Au grid with a linewidth of 5μm using an online alignment method based on dual positioning balls to indicate the target and backlighter.This paper describes the optical design,adjustment method,and experimental results of a toroidal crystal system in a laboratory and laser facility.
基金Supported by Shaanxi Science and Technology Research Plan Program,Shaanxi,China,No. 2020SF-106
文摘BACKGROUND Pleural effusions occur for various reasons,and their diagnosis remains challenging despite the availability of different diagnostic modalities.Medical thoracoscopy(MT)can be used for both diagnostic and therapeutic purposes,especially in patients with undiagnosed pleural effusion.AIM To assess the diagnostic efficacy and safety of MT in patients with pleural effusion of different causes.METHODS Between January 1,2012 and April 30,2021,patients with pleural effusion underwent MT in the Department of Respiratory Medicine,The Second Affiliated Hospital of Xi’an Jiaotong University(Shaanxi,China).According to the discharge diagnosis,patients were divided into malignant pleural effusion(MPE),tuberculous pleural effusion(TBPE),and inflammatory pleural effusion(IPE)groups.General information,and tuberculosis-and effusion-related indices of the three groups were analyzed.The diagnostic yield,diagnostic accuracy,performance under thoracoscopy,and complications of patients were compared among the three groups.Then,the significant predictive factors for diagnosis between the MPE and TBPE groups were analyzed.RESULTS Of the 106 patients enrolled in this 10-year study,67 were male and 39 female,with mean age of 57.1±14.184 years.Among the 74 thoracoscopy-confirmed patients,41(38.7%)had MPE,21 had(19.8%)TBPE,and 32(30.2%)were undiagnosed.Overall diagnostic yield of MT was 69.8%(MPE:75.9%,TBPE:48.8%,and IPE:75.0%,with diagnostic accuracies of 100%,87.5%,and 75.0%,respectively).Under thoracoscopy,single or multiple pleural nodules were observed in 81.1%and pleural adhesions in 34.0%with pleural effusions.The most common complication was chest pain(41.5%),followed by chest tightness(11.3%)and fever(10.4%).Multivariate logistic regression analyses showed effusion appearance[odds ratio(OR):0.001,95%CI:0.000-0.204;P=0.010]and carcinoembryonic antigen(OR:0.243,95%CI:0.081-0.728;P=0.011)as significant for differentiating MPE and TBPE,with area under the receiver operating characteristic curve of 0.977(95%CI:0.953-1.000;P<0.001).CONCLUSION MT is an effective,safe,and minimally invasive procedure with high diagnostic yield for pleural effusion of different causes.
文摘In this paper, the development of smart medical autonomous technology is considered. An example of a smart medical autonomous distributed system for diagnostics is also discussed. To develop this system for medical image analysis we review several processing methods. The use of the cuneiform dehydration method for medical diagnosis is considered. The experimental results obtained for blood serum dehydrated films are presented. The author proposes an algorithm for the primary identification of structures formed in the films and their use for automated detection of various structures for diagnostic purposes. The paper describes the first stage of image processing, i.e. the selection of filtering types for the correct identification of structural features and characteristics of the images. The results of filtering and some computational results of various types of structures in the films are presented.
基金This research has been funded by Direccion General de Investigaciones of Universidad Santiago de Cali under call No.01-2021。
文摘The hepatitis B virus is the most deadly virus,which significantly affects the human liver.The termination of the hepatitis B virus is mandatory and can be done by taking precautions as well as a suitable cure in its introductory stage;otherwise,it will become a severe problem and make a human liver suffer from the most dangerous diseases,such as liver cancer.In this paper,two medical diagnostic systems are developed for the diagnosis of this life-threatening virus.The methodologies used to develop thesemodels are fuzzy logic and the neuro-fuzzy technique.The diverse parameters that assist in the evaluation of performance are also determined by using the observed values from the proposed system for both developedmodels.The classification accuracy of a multilayered fuzzy inference system is 94%.The accuracy with which the developed medical diagnostic system by using Adaptive Network based Fuzzy Interference System(ANFIS)classifies the result corresponding to the given input is 95.55%.The comparison of both developed models on the basis of their performance parameters has been made.It is observed that the neuro-fuzzy technique-based diagnostic system has better accuracy in classifying the infected and non-infected patients as compared to the fuzzy diagnostic system.Furthermore,the performance evaluation concluded that the outcome given by the developed medical diagnostic system by using ANFIS is accurate and correct as compared to the developed fuzzy inference system and also can be used in hospitals for the diagnosis of Hepatitis B disease.In other words,the adaptive neuro-fuzzy inference system has more capability to classify the provided inputs adequately than the fuzzy inference system.
文摘Medical diagnostic tables are widely used inthemedical diagnostic equipment. For multifarious diagnostic needs, the medical diagnostic table works in various operating modes. In order to ensure patient safety, safety factor of medical diagnostic table must meet safety requirement. The paper puts forward a method to find relations between key parameters and stress of table, identify maximum stress modes, reduce modes number of load test, and remove conservative high stress areas from finite element analysis result, by synthesizingthestress result of finite element analysis and measurement data for various operating modes of medical diagnostic table. It will help shorten test time, avoid over strength design, and reduce table’s cost. An application example of the method is presented by evaluating a specific CT medical diagnostictable. This method can be a reference for safety evaluation of all medical diagnostic tables.
文摘1 BackgroundIt is well known that the radiology diagnostic report as the essential component of the patient′s permanent health record,which radiography is an indispensable diagnostic tool.Our duties are observe the imaging carefully and write a
文摘A diagnostic system of soft x-ray diode-array was set up for HT-7 superconducting tokamak. The system consists of two slot-aperture cameras and is capable of measuring the soft x-ray emission from the plasma on HT-7 device with a high resolution in space and a high response in time. Both cameras, located separately in a horizontal port and a vertical port each with thirty-seven detectors of An-Si surface-barrier diode (SBD) can view the same toroidal cross-section of the plasma from different poloidal chords. In this paper, the structure, principle and performance of the diagnostic system are described and some experimental results observed are presented.
基金partially supported by the Natural Science Foundation of China(Nos.12004353,11975214,11991071,11905202,12175212,and 12120101005)the Key Laboratory Foundation of the Science and Technology on Plasma Physics Laboratory(Nos.6142A04200103 and 6142A0421010).
文摘Currently,with the advent of high-repetition-rate laser-plasma experiments,the demand for online diagnosis for the X-ray spectrum is increasing because the laser-plasma-generated X-ray spectrum is very important for characterizing electron dynamics and applications.In this study,scintillators and silicon PIN(P-type–intrinsic-N-type semiconductor)diodes were used to construct a wideband online filter stack spectrometer.The X-ray sensor and filter arrangement was optimized using a genetic algorithm to minimize the condition number of the response matrix.Consequently,the unfolding error was significantly reduced based on numerical experiments.The detector responses were quantitatively calibrated by irradiating the scintillator and PIN diode with various nuclides and comparing the measuredγ-ray peaks.A prototype 15-channel spectrometer was developed by integrating an X-ray detector with front-and back-end electronics.The prototype spectrometer could record X-ray pulse signals at a repetition rate of 1 kHz.Furthermore,an optimized spectrometer was employed to record the real-time spectra of laser-driven bremsstrahlung sources.This optimized spectrometer offers a compact solution for spectrum diagnostics of ultrashort X-ray pulses,exhibiting improved accuracy in terms of spectrum measurements and repetition rates,and could be widely used in next-generation high-repetition-rate high-power laser facilities.
基金supported by the project“PARIDE”(Perovskite Advanced Radiotherapy&Imaging Detectors),funded under the Regional Research and Innovation Programme POR-FESR Lazio 2014-2020(project number:A0375-2020-36698).
文摘Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.
文摘X-Ray sources, detectors and optical components are now used in a wide range of applications. What is crucial is the absolute calibration of such devices to permit a quantitative assessment of the system under study. A new X-ray laboratory has been built in Frascati (ENEA) to develop diagnostics for nuclear fusion experiments and study applications of these X-ray techniques in other domains, like new material science, non destructive tests and so on. An in-house developed selfconsistent calibration procedure is described that permits the absolute calibration of sources (X-ray emitted fluxes) and detectors (detection efficiencies) as function of the X-ray photon energy, in the range 2 - 120 keV. The calibration procedure involves the use of an in-house developed code that also predicts the spectral response of any detector in any experimental condition that can be setup in the laboratory. The procedure has been then applied for the calibration and characterisation of gas and solid state imaging detectors, such as Medipix-2, GEM gas detector, CCD camera, Cd-Te C-MOS imager, demonstrating the versatility of the method developed here.
文摘Diagnostic imaging plays a key role in the diagnosis and management of inflammatory bowel disease(IBD). However due to the relapsing nature of IBD, there is growing concern that IBD patients may be exposed to potentially harmful cumulative levels of ionising radiation in their lifetime, increasing malignant potential in a population already at risk. In this review we explore the proportion of IBD patients exposed to high cumulative radiation doses, the risk factors associated with higher radiation exposures, and we compare conventional diagnostic imaging with newer radiation-free imaging techniques used in the evaluation of patients with IBD. While computed tomography(CT) performs well as an imaging modality for IBD, the effective radiation dose is considerably higher than other abdominal imaging modalities. It is increasingly recognised that CT imaging remains responsible for the majority of diagnostic medical radiation to which IBD patients are exposed. Magnetic resonance imaging(MRI) and small intestine contrast enhanced ultrasonography(SICUS) have now emerged as suitable radiation-free alternatives to CT imaging, with comparable diagnostic accuracy. The routine use of MRI and SICUS for the clinical evaluation of patients with known or suspected small bowel Crohn's disease is to be encouraged wherever possible. More provision is needed for out-of-hours radiation-free imaging modalities to reduce the need for CT.
文摘Diagnostic errors are important in all branches of medicine because they are an indication of poor patient care. Since the early 1970s,physicians have been subjected to an increasing number of medical malpractice claims. Radiology is one of the specialties most liable to claims of medical negligence.Most often,a plaintiff's complaint against a radiologist will focus on a failure to diagnose. The etiology of radiological error is multi-factorial.Errors fall into recurrent patterns.Errors arise from poor technique,failures of perception,lack of knowledge and misjudgments.The work of diagnostic radiology consists of the complete detection of all abnormalities in an imaging examination and their accurate diagnosis. Every radiologist should understand the sources of error in diagnostic radiology as well as the elements of negligence that form the basis of malpractice litigation.Error traps need to be uncovered and highlighted,in order to prevent repetition of the same mistakes.This article focuses on the spectrum of diagnostic errors in radiology, including a classification of the errors,and stresses the malpractice issues in mammography,chest radiology and obstetric sonography.Missed fractures in emergency and communication issues between radiologists and physicians are also discussed.
基金This research was funded by the Deanship of Scientific Research at Princess Nourah Bint Abdulrahman University through the Fast-track Research Funding Program.
文摘Effective medical diagnosis is dramatically expensive,especially in third-world countries.One of the common diseases is pneumonia,and because of the remarkable similarity between its types and the limited number of medical images for recent diseases related to pneumonia,themedical diagnosis of these diseases is a significant challenge.Hence,transfer learning represents a promising solution in transferring knowledge from generic tasks to specific tasks.Unfortunately,experimentation and utilization of different models of transfer learning do not achieve satisfactory results.In this study,we suggest the implementation of an automatic detectionmodel,namelyCADTra,to efficiently diagnose pneumonia-related diseases.This model is based on classification,denoising autoencoder,and transfer learning.Firstly,pre-processing is employed to prepare the medical images.It depends on an autoencoder denoising(AD)algorithm with a modified loss function depending on a Gaussian distribution for decoder output to maximize the chances for recovering inputs and clearly demonstrate their features,in order to improve the diagnosis process.Then,classification is performed using a transfer learning model and a four-layer convolution neural network(FCNN)to detect pneumonia.The proposed model supports binary classification of chest computed tomography(CT)images and multi-class classification of chest X-ray images.Finally,a comparative study is introduced for the classification performance with and without the denoising process.The proposed model achieves precisions of 98%and 99%for binary classification and multi-class classification,respectively,with the different ratios for training and testing.To demonstrate the efficiency and superiority of the proposed CADTra model,it is compared with some recent state-of-the-art CNN models.The achieved outcomes prove that the suggested model can help radiologists to detect pneumonia-related diseases and improve the diagnostic efficiency compared to the existing diagnosis models.
基金supported in part by Zayed University,office of research under Grant No.R17089.
文摘The unavailability of sufficient information for proper diagnosis,incomplete or miscommunication between patient and the clinician,or among the healthcare professionals,delay or incorrect diagnosis,the fatigue of clinician,or even the high diagnostic complexity in limited time can lead to diagnostic errors.Diagnostic errors have adverse effects on the treatment of a patient.Unnecessary treatments increase the medical bills and deteriorate the health of a patient.Such diagnostic errors that harm the patient in various ways could be minimized using machine learning.Machine learning algorithms could be used to diagnose various diseases with high accuracy.The use of machine learning could assist the doctors in making decisions on time,and could also be used as a second opinion or supporting tool.This study aims to provide a comprehensive review of research articles published from the year 2015 to mid of the year 2020 that have used machine learning for diagnosis of various diseases.We present the various machine learning algorithms used over the years to diagnose various diseases.The results of this study show the distribution of machine learning methods by medical disciplines.Based on our review,we present future research directions that could be used to conduct further research.
文摘Background: Systematic chest X-ray is the most prescribed examination by occupational physicians during periodic medical check-ups in our context, unlike in most countries where this practice has been discontinued. Objective: The objective was to determine the diagnostic yield and cost-effectiveness of chest radiography during periodic medical check-ups of workers in Ngaoundere. Materials and Methods: A cross-sectional and descriptive study was carried out in Ngaoundere Regional Hospital from January to December 2018, concerning all persons coming to perform a systematic chest X-ray in the context of the periodic medical check-up having been consented to participate in the study. Posteroanterior (PA) chest radiographs were obtained from all workers during this periodic medical check-up. The variables studied were: age, sex, clinical manifestations, antecedents, job type, cost, and chest X-ray results. Statistical analysis was performed using the Sphinx Plus2-Lexica-V5 Edition software. Results: 753 workers were selected for this study, of whom 88.04% were men and 11.96% were women, a sex ratio H/F is of 7.4, the average age was 39 ± 7.89 years with extremes of 24 and 56 years, the most frequent job type was the administration (38.37%), the storekeepers (17.92) and the drivers (15.27%), most of them were asymptomatic (97.47%), some had cough (2.52%), chest pain (2.12%), dyspnea (0.26%) and fever (0.13%). History was dominated by lung infection (2.39%), pleurisy (1.06%) and tuberculosis (0.79%). 7.43% of workers occasionally smoked tobacco and consumed alcohol. 41 cases of pathologies (5.44%) were found on the chest X-ray, including 1 case (0.13%) of evolutionary pathology, 40 cases (5.31%) of sequelae pathologies. When the results of the chest X-ray are compared with the clinical signs and the pathological history of the workers, it is found that the only case with evolutionary abnormalities on the chest X-ray showed clinical signs and that the other cases with sequelae abnormalities had either clinical signs or antecedents related to these abnormalities. The cost of a chest X-ray at the time of our study was 5,000 FCFA ($8.59), for a total of 3,765,000 FCFA ($6473.74) for all the X-rays performed. Conclusion: In view of the low rate of abnormalities on the chest X-ray and the sequelae nature of the pathologies, it can be said that the routine X-ray of the chest during the periodic medical check-ups has a low diagnostic yield and a low cost-effectiveness ratio and is not profitable. It should be non-systematic and case-by-case based on the clinical context and background of workers.
基金National Natural Science Foundation of China (No. 11575184).
文摘A novel real time fast electron bremsstrahlung (FEB) diagnostic system based on the lutetium yttrium oxyorthosilicate scintillators (LYSO) and silicon photomultipliers (SiPM) has been developed for tokamak.The diagnostic system is dedicated to study the FEB emission in the hard x-ray (HXR) energy range between 10 and 200 keV during the lower hybrid current drive.The system consists of a detection module and three data acquisition and processing (DAP)boards.The detection module consists of annulus LYSO-SiPM detector array and a 12-channel preamplifier module.The DAP boards upload the data to the host computer for displaying and storing through PXI bus.The time and space resolutions of the system are 10 ms and 4 cm,respectively.The experimental results can show the evolution over time and the spatial distribution of FEB.This paper presents the system performance and typical discharge results.
文摘This research presents the results of investigation of laser_polarization fluorescence ofbiological layers(histological sections,cy tological smears)in the task of diagnostics and differ-en tiation of early stages of cancer:Dysplasia-cervical microinvasive carcinoma of cervic uteri.The analytical conditions of polarization-optimal probing of biological layers were determinedbasing on the model of linear birefringence and dichroism of birefringent(fibrllar,porphyrin)networks.The technique of polarization-variable laser autofluorescence was developed andexperimentally tested.The objective criteria(statistical moments)of differentiation of histo-logical sections autofluorescent images of endometrium biopsy and cytological smears of itmucous coat were defined.The operational characteristics(sensitivity,speifity,accuracy)ofthis technique were determined concerning the positions of probative medicine,and clinical efficiency.
文摘Objectives: To assess the patients and health personnel’s level of awareness on risks related to ionizing radiation during CT scan. Materials and methods: Three questionnaires were addressed to patients, prescribing physicians, and the medical imaging staff for three hospitals respectively. This permitted us to assess their knowledge on the benefits and risks of the required medical exam, based on the dangers of being exposed to X-rays, especially induced-radiation cancer following the amount of X-rays received during a CT scan and the possibility of not receiving radiation as tools of diagnosis. Results: 150 patients, 84 referring doctors of CT scan tests and 60 medical imaging personnel were retained. For patients, only 7.1% received information on the benefits and risks of their exams, and 34.4% believed that x-rays were harmful to their health. For the prescribers, 46.7% took into account the benefits/risk ratio before prescribing a test and only 16.7% of the referring doctors have informed the patient of the risks related to X-ray. 90% of the medical imaging staff ensures that the required test is justified, and 50% informed the patient on the risks associated with their radiation exposure, and the increased risk of developing cancer. 65% of the imaging staff could not estimate the dose that the patient will receive during the medical test. 25% mentioned the dose received during the acquisition in the patient’s exam report. Conclusion: This study confirms that the referring doctors, the patients, and the radiologists have a low knowledge concerning the risks associated with radiation exposure during a CT scan assessment. We will therefore say that patients and prescribers are not aware of the doses of radiation on CT and their possible risks, even though there is a risk of developing cancer.