Radiography Image Classification Using Deep Convolutional Neural Networks

Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can be used to identify each of these anomalies in the chest x-ray images. Convolutional neural networks (CNNs) have shown great success in the fields of image recognition and image classification since there are numerous large-scale annotated image datasets available. The classification of medical images, particularly radiographic images, remains one of the biggest hurdles in medical diagnosis because of the restricted availability of annotated medical images. However, such difficulty can be solved by utilizing several deep learning strategies, including data augmentation and transfer learning. The aim was to build a model that would detect abnormalities in chest x-ray images with the highest probability. To do that, different models were built with different features. While making a CNN model, one of the main tasks is to tune the model by changing the hyperparameters and layers so that the model gives out good training and testing results. In our case, three different models were built, and finally, the last one gave out the best-predicted results. From that last model, we got 98% training accuracy, 84% validation, and 81% testing accuracy. The reason behind the final model giving out the best evaluation scores is that it was a well-fitted model. There was no overfitting or underfitting issues. Our aim with this project was to make a tool using the CNN model in R language, which will help detect abnormalities in radiography images. The tool will be able to detect diseases such as Pneumonia, Covid-19, Effusions, Infiltration, Pneumothorax, and others. Because of its high accuracy, this research chose to use supervised multi-class classification techniques as well as Convolutional Neural Networks (CNNs) to classify different chest x-ray images. CNNs are extremely efficient and successful at reducing the number of parameters while maintaining the quality of the primary model. CNNs are also trained to recognize the edges of various objects in any batch of images. CNNs automatically discover the relevant aspects in labeled data and learn the distinguishing features for each class by themselves.

A characterization study on perovskite X-ray detector performance based on a digital radiography system

X-ray imaging technologies such as digital radiography(DR),is an important aspect of modern non-destructive testing and medical diagnosis.Innovative flexible X-ray detector technologies have recently been proposed and are now receiving increasing attention owing to their superior material flexibility compared with traditional flat-panel detectors.This work aims to study these innovative flexible X-ray detectors in terms of their effectiveness in DR imaging,such as detection efficiency and spatial resolution.To achieve this goal,first,a Monte Carlo model was developed and calibrated to an in-lab 150 kV DR imaging system containing a flat-panel X-ray detector.Second,the validated model was updated with various types of flexible X-ray detectors to assess their performance in nearly realistic conditions.Key parameters such as the detection efficiency pertaining to the crystal material and thickness were studied and analyzed across a broader energy range up to 662 keV.Finally,the imaging performance of the different detectors was evaluated and compared to that of the flat-panel detector in the 150 kV DR imaging system.The results show that the flexible detectors such as the CsPbBr3crystal detector deliver promising performance in X-ray imaging and can be applied to a wider range of application scenarios,especially those requiring accurate detection at challenging angles.

Relationship between neonatal respiratory distress syndrome pulmonary ultrasonography and respiratory distress score,oxygenation index,and chest radiography grading

BACKGROUND Accurate condition assessment is critical for improving the prognosis of neonatal respiratory distress syndrome(RDS),but current assessment methods for RDS pose a cumulative risk of harm to neonates.Thus,a less harmful method for assessing the health of neonates with RDS is needed.AIM To analyze the relationships between pulmonary ultrasonography and respiratory distress scores,oxygenation index,and chest X-ray grade of neonatal RDS to identify predictors of neonatal RDS severity.METHODS This retrospective study analyzed the medical information of 73 neonates with RDS admitted to the neonatal intensive care unit of Liupanshui Maternal and Child Care Service Center between April and December 2022.The pulmonary ultrasonography score,respiratory distress score,oxygenation index,and chest Xray grade of each newborn before and after treatment were collected.Spearman correlation analysis was performed to determine the relationships among these values and neonatal RDS severity.RESULTS The pulmonary ultrasonography score,respiratory distress score,oxygenation index,and chest X-ray RDS grade of the neonates were significantly lower after treatment than before treatment(P<0.05).Spearman correlation analysis showed that before and after treatment,the pulmonary ultrasonography score of neonates with RDS was positively correlated with the respiratory distress score,oxygenation index,and chest X-ray grade(ρ=0.429–0.859,P<0.05).Receiver operating characteristic curve analysis indicated that pulmonary ultrasonography screening effectively predicted the severity of neonatal RDS(area under the curve=0.805–1.000,P<0.05).CONCLUSION The pulmonary ultrasonography score was significantly associated with the neonatal RDS score,oxygenation index,and chest X-ray grade.The pulmonary ultrasonography score was an effective predictor of neonatal RDS severity.

Chest Radiography: General Practitioners’ Compliance with Recommendations

Introduction: Chest radiography is the most frequently prescribed imaging test in general practice in France. We aimed to assess the extent to which general practitioners follow the recommendations of the French National Authority for Health in prescribing chest radiography. Methodology: We conducted a retrospective analysis study, in two radiology centers belonging to the same group in Saint-Omer and Aire-sur-la-Lys, of requests for chest radiography sent by general practitioners over the winter period between December 22, 2013, and March 21, 2014, for patients aged over 18 years. Results: One hundred and seventy-seven requests for chest X-rays were analyzed, 71.75% of which complied with recommendations. The most frequent reason was the search for bronchopulmonary infection, accounting for 70.08% of prescriptions, followed by 11.2% for requests to rule out pulmonary neoplasia, whereas the latter reason did not comply with recommendations. Chest X-rays contributed to a positive diagnosis in 28.81% of cases. The positive diagnosis was given by 36.22% of the recommended chest X-rays, versus 10% for those not recommended. Conclusion: In most cases, general practitioners follow HAS recommendations for prescribing chest X-rays. Non-recommended chest X-rays do not appear to make a major contribution to diagnosis or patient management, confirming the value of following the recommendations of the French National Authority for Health.

Monte Carlo simulation for bremsstrahlung and photoneutron yields in high-energy x-ray radiography

This paper reports on the results of calculations using a Monte Carlo code （MCNP5） to study the properties of photons, electrons and photoneutrons obtained in the converted target and their transportations in x-ray radiography. A comparison between measurements and calculations for bremsstrahlung and photoneutrons is presented. The radiographic rule and the effect of the collimator on the image are studied with the experimental model. The results provide exact parameters for the optimal design of radiographic layout and shielding systems.

Resolution analysis of thermal neutron radiography based on accelerator-driven compact neutron source

Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial applications.Recently,thermal neutron radiography experiments based on a D-T neutron generator performed by Hefei Institutes of Physical Science indicated a significant resolution deviation between the experimental results and the values calculated using the traditional resolution model.The experimental result was up to 23%lower than the calculated result,which hinders the achievement of the design goal of a compact neutron radiography system.A GEANT4 Monte Carlo code was developed to simulate the CTNR process,aiming to identify the key factors leading to resolution deviation.The effects of a low collimation ratio and high-energy neutrons were analyzed based on the neutron beam environment of the CTNR system.The results showed that the deviation was primarily caused by geometric distortion at low collimation ratios and radiation noise induced by highenergy neutrons.Additionally,the theoretical model was modified by considering the imaging position and radiation noise factors.The modified theoretical model was in good agreement with the experimental results,and the maximum deviation was reduced to 4.22%.This can be useful for the high-precision design of CTNR systems.

Flash X-ray radiography technique to study the high velocity impact of soft projectile on E-glass/epoxy composite material

In the present paper, the high velocity impact of 9 mm soft lead projectile on 10 mm and 30 mm thick Eglass/epoxy composites was studied using a 450 kV Flash X-ray radiography(FXR) system. The basic parameters of FXR imaging, such as effect of ratio of target to film(TF) and source to target(ST) distances and X-ray penetration thickness of the composite material were optimized based on clarity and the actual dimensions of the objects. The optimized parameters were used in the FXR imaging of the ballistic event of 9 mm soft projectile on E-glass/epoxy composite. The real time deformation patterns of both the projectile and composite target during the ballistic impact were captured and studied at different time intervals. The notable failure modes of the 10 mm thick target with time include fibre breakage, bulging on the back side, delamination, recovery of the bulging, reverse bulging and its recovery. However, with increase in thickness of the target to 30 mm the only failure mechanism observed is the breaking of fibres. The ballistic impact event was also numerically simulated using commercially available LS-DYNA software. The numerically simulated deformation patterns of the projectile and target at different time intervals are closely matching with the corresponding radiographic images.

Low Energy Plasma Focus as an Intense X-ray Source for Radiography

Study on X-ray emission from a low energy (1.8 kJ) plasma focus devicepowered by a 9 μF capacitor bank, charged at 20 kV and giving peak discharge current of about 175kA by using a lead-inserted copper-tapered anode is reported. The X-ray yield in different energywindows is measured as a function of hydrogen filling pressure. The maximum yield in 4π-geometry isfound to be (27.3+-1.1) J and corresponding wall plug efficiency for X-ray generation is 1.52+-0.06%. X-ray emission, presumably due to bombarding activity of electrons in current sheath at theanode tip was dominant, which is confirmed by the pinhole images. The feasibility of the device asan intense X-ray source for radiography is demonstrated.

X-Pinches as Broadband Sources of X-Rays for Radiography

Two methods of using the X-pinch as a source of X-ray radiation for radiography of biological objects are presented. X-pinches are found to be a very flexible method for generation of radiation over a wide spectral range and provide a high spatial and temporal resolution.

Noise analysis of grating-based x-ray differential phase-contrast imaging with angular signal radiography

X-ray phase-contrast imaging is one of the novel techniques,and has potential to enhance image quality and provide the details of inner structures nondestructively.In this work,we investigate quantitatively signal-to-noise ratio（SNR） of grating-based x-ray phase contrast imaging（GBPCI） system by employing angular signal radiography（ASR）.Moreover,photon statistics and mechanical error that is a major source of noise are investigated in detail.Results show the dependence of SNR on the system parameters and the effects on the extracted absorption,refraction and scattering images.Our conclusions can be used to optimize the system design for upcoming practical applications in the areas such as material science and biomedical imaging.

Fast and Low Cost X-Ray Stereoradiography Displayed on a 3D Monitor

Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadolinium oxy-sulfide (GOS) fluorescent screen and a Cannon 500D digital camera were designed and constructed for real-time and near real-time x-ray imaging. The camera was connected to a laptop computer via USB port to allow remote camera setting and control as well as view image on the computer. The system was tested with x-rays generated from a Rigaku x-ray tube for its response at various camera settings and exposure times. The image brightness increased with increasing of the camera ISO setting and with the exposure time as expected. To test the system performance, two test specimens were radiographed including a video camera and a floppy disk drive as well as two simulated specimens. Each of the test specimens was also radiographed at two positions by moving the specimens approximately 6 cm from the first position. The two radiographs of each specimen were then combined to make an anaglyph image that could be viewed in 3D on a normal LCD or LED monitor by using appropriate color glasses. When the two radiographs were combined to make MPO (multiple object) file format, it could be viewed in 3D on a 3D monitor with or without 3D glasses depending on type of the monitor. The developed system could be conveniently employed for routine inspection of a specimen both in 2D and 3D within a minute.

Comparison between Predicted and Measured X-Ray Output in Some Conventional Radiography Units

This study aims to investigate how accurate are TASMICS and TASMIP models in predicting the X-ray output of some Conventional Radiology X-ray units with high frequency generators. The X-ray output in microgray per milliampere seconds (μGy/mAs) at 100 cm from the X-ray tube was determined for selected high voltages and taking into account the total filtration. The X-ray output was then measured directly with the multi-purpose detectors (MPD), Raysafe X2. The maximum relative error between measured and predicted values was found to be equal to 20%. The maximum relative error between measured and predicted values obtained demonstrates the difficulty of accurately predicting the X-ray tube output using TASMICS and TASMIP models since they are based on fixed anode angles and different composition of the tungsten anode.

Radiography of Clavicle Fractures— A Review of the Literature —Do Various Radiographic Views of Clavicle Fractures Affect the Management Plan?

Introduction: Fractures of the clavicle are common and make up 5% - 10% of all fractures. Treatment options in part depend on the location of the fracture along the bone and degree of displacement. These two parameters are best determined by good quality, standardized radiographs of the clavicle. We reviewed the literature to determine the optimal radiographs of clavicle fractures and their influence on the treatment plan. Methods: A comprehensive search of Medline? database was undertaken with the following search terms and MeSH headings: clavicle, fractures, bone, radiography, and X-ray. We included articles in English published from 1950 to present. We ruled out fractures in children, fracture dislocations, open fractures, those with neurological and vascular injuries and fractures involving the acromioclavicular or sternoclavicular joints. Findings: Of the 821 citations obtained, only four studies proved eligible. In the most pertinent, four orthopaedic surgeons were shown standard views (antero-posterior and 20&#176;cephalic tilt) of 50 clavicle fractures and then additional two views (45&#176;cephalic and caudal tilt), and found that alternative views influenced their decision making, with more surgeons opting for surgical fixation. In a different study, it was shown that orthogonal views of the clavicle increased surgeons’ understanding and improved their treatment of these fractures. The third paper was a case series on clavicle fractures that were missed on the initial antero-posterior radiograph, and the fourth paper postulated that postero-anterior views of the thorax were most accurate in determining length of the clavicle. Conclusion: Studies showing an optimal view for assessment of clavicle fractures with a decision to then progressing to operative fixation are few, but the evidence points towards surgical fixation when alternative views of mid-shaft clavicle fractures are present.

In situ study on columnar-equiaxed transition and anaxial columnar dendrite growth of Al-15%Cu alloy by synchrotron radiography

Directional solidification of Al-15% （mass fraction） Cu alloy was investigated by in situ and real time radiography which was performed by Shanghai synchrotron radiation facility （SSRF）. The imaging results reveal that columnar to equiaxed transition （CET） is provoked by external thermal disturbance. The detaching and floating of fragments of dendrite arms are the prelude of the transition when the solute boundary layer in front of the solid-liquid interface is thin. And the dendrite triangular tip is the fracture sensitive zone. When the conditions are suitable, new dendrites can sprout and grow up. This kind of dendrite has no obvious stem and is named anaxial columnar dendrites.

Development of Brief Image Quality Evaluation Criteria for Digital OrthoPantomography （OPG） Images in Dental Radiography

An OPG （orthopantmography） is an extra-oral radiographic imaging method which provides a panoramic or wide view of both jaws and teeth on a single image. Digital OPG images provide high contrast with more details of the dentitions. The research main objective was to produce sophisticated and effective criteria that can be used by any radiographer with sound knowledge to identify common errors of digital OPG images and to increase the concern of high frequency of errors to minimize them to give an optimum image quality. The study was designed as retrospective cross sectional study. Hundred digital OPG images are evaluated by three qualified radiographers who had dental radiography experience and four student radiographers. Paired t-test was used to see the difference between the responses of radiographers and student radiographers. Kruskal-Wallis Test was used to see difference between each evaluator. Possible errors of OPG were divided into four main categories （identification, artifact, anatomical coverage and patient positioning）. Each main category consists of sub-categories. Values of subcategories were given according to their importance to get the total of 100% for each main category. The results showed that there is no significant difference between radiographers and student radiographers’ responses and also between each evaluator. Hence it shows that the criteria were an easy understandable and user-friendly tool. And results showed the frequent error category was loss of anatomical coverage and frequent error was absence of positioning the tongue against the palate.

Evaluation of an asymptomatic COVID-19 patient post-surgery with chest radiography: A surgeon’s dilemma

Routine chest radiography is not a requirement in post-surgery cardiac bypass patients.However,the safety of abandoning routine chest radiographs in critically ill patients remains uncertain.Surgery in an asymptomatic coronavirus disease 2019(COVID-19)patient presents additional challenges in postoperative management.Chest radiography remains a valuable tool for assessment of all patients,even a stable one.Management of surgical patients as an emergency in an asymptomatic COVID-19 case remains a surgeon’s dilemma.

Contrast sensitivity in 14 MeV fast neutron radiography

Fast neutron radiography(FNR) is an effective non-destructive testing technique.Due to the scattering effect and low detection efficiency,the detection limit of FNR under certain conditions cannot be determined.In order to obtain the minimum detectable thickness by FNR,we studied the contrast sensitivity of FNR lead samples,both theoretically and experimentally.We then clarified the relationship between pixel value and irradiation time,and sample materials and thickness.Our experiment,using a4-cm-thick lead sample,verified our theoretical expression of FNR contrast sensitivity.

Digital radiography of crush thoracic trauma in the Sichuan earthquake

AIM:To investigate the features of crush thoracic trauma in Sichuan earthquake victims using chest digital radiography(CDR).METHODS:We retrospectively reviewed 772 CDR of 417 females and 355 males who had suffered crush thoracic trauma in the Sichuan earthquake.Patient age ranged from 0.5 to 103 years.CDR was performed between May 12,2008 and June 7,2008.We looked for injury to the thoracic cage,pulmonary parenchyma and the pleura.obtained in 349 patients,the remaining 423 patients underwent only AP CDR.Thoracic cage fractures,pulmonary contusion and pleural injuries were noted in 331(42.9%;95% CI:39.4%-46.4%),67 and 135 patients,respectively.Of the 256 patients with rib fractures,the mean number of fractured ribs per patient was 3.Rib fractures were mostly distributed from the 3rd through to the 8th ribs and the vast majority involved posterior and lateral locations along the rib.Rib fractures had a significant positive association with non-rib thoracic fractures,pulmonary contusion and pleural injuries(P < 0.001).The number of rib fractures and pulmonary contusions were significant factors associated with patient death.CONCLUSION:Earthquake-related crush thoracic trauma has the potential for multiple fractures.The high number of fractured ribs and pulmonary contusions were significant factors which needed appropriate medical treatment.

Comparison of conventional radiography and MDCT in suspected scaphoid fractures

AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography(MDCT) in suspected scaphoid fractures.METHODS: One hundred twenty-four consecutive patients were enrolled in our study who had suffered from a wrist trauma and showed typical clinical symptoms suspicious of an acute scaphoid fracture. All patients had initially undergone conventional radiography. Subsequent MDCT was performed within 10 d because of persisting clinical symptoms. Using the MDCT data as the reference standard, a fourfold table was used to classify the test results. The effective dose and impaired energy were assessed in order to compare the radiation burden of the two techniques. The Wilcoxon test was performed to compare the two diagnostic modalities.RESULTS: Conventional radiography showed 34 acute fractures of the scaphoid in 124 patients(42.2%). Subsequent MDCT revealed a total of 42 scaphoid fractures. The sensitivity of conventional radiography for scaphoid fracture detection was 42.8% and its specificity was 80% resulting in an overall accuracy of 59.6%. Conventional radiography was significantly inferior to MDCT(P < 0.01) concerning scaphoidfracture detection. The mean effective dose of MDCT was 0.1 m Sv compared to 0.002 m Sv of conventional radiography.CONCLUSION: Conventional radiography is insufficient for accurate scaphoid fracture detection. Regarding the almost negligible effective dose, MDCT should serve as the first imaging modality in wrist trauma.

Imaging internal density structure of the Laoheishan volcanic cone with cosmic ray muon radiography

Muon radiography is a promising technique for imaging the internal density structures of targets such as tunnels,pyramids,and volcanoes up to a scale of a few hundred meters by measuring the flux attenuation of cosmic ray muons after they have traveled through these targets.In this study,we conducted experimental muon radiography of one of the volcanoes in the Wudalianchi area in Northeast China to image its internal density structure.The muon detector used in this study was composed of plastic scintillators and silicon photomultipliers.After approximately one and a half months of observing the crater and conduit of the Laoheishan volcano cone in Wudalianchi from September 23^(rd) to November 10^(th) 2019,more than 3 million muon tracks fulfilling the data selection criteria were collected.Based on the muon samples and high-resolution topography obtained through aerial photogrammetry using an unmanned aerial vehicle,a density image of the Laoheishan volcano cone was constructed.The results obtained in this experiment demonstrate the feasibility of using a radiography technique based on plastic scintillator detectors.To obtain the density distribution,we performed a detailed background analysis and found that low-energy charged particles dominated the background noise.Relatively higher densities were found near the surface of the volcanic cone,whereas relatively lower densities were found near the center of the volcanic cone.The experiment in this study is the first volcano muon tomography study performed in China.Our work provides an important reference for future research.