Automated chest radiography and mass systematic screening for tuberculosis

2020 ◽  
Vol 24 (7) ◽  
pp. 665-673 ◽  
Author(s):  
F. Madhani ◽  
R. A. Maniar ◽  
A. Burfat ◽  
M. Ahmed ◽  
S. Farooq ◽  
...  
Keyword(s):  
Chest Radiography ◽  
Strong Association ◽  
Diagnostic Testing ◽  
X Rays ◽  
Computer Aided Detection ◽  
Data Collection Tool ◽  
Systematic Screening ◽  
X Ray ◽  
Detection Software ◽  
Using Data

BACKGROUND: Systematic screening for TB using automated chest radiography (ACR) with computer-aided detection software (CAD4TB) has been implemented at scale in Karachi, Pakistan. Despite evidence supporting the use of ACR as a pre-screen prior to Xpert® MTB/RIF diagnostic testing in presumptive TB patients, there has been no data published on its use in mass screening in real-world settings.METHOD: Screening was undertaken using mobile digital X-ray vehicles at hospital facilities and community camps. Chest X-rays were offered to individuals aged ≥15 years, regardless of symptoms. Those with a CAD4TB score of ≥70 were offered Xpert testing. The association between Xpert positivity and CAD4TB scores was examined using data collected between 1 January and 30 June 2018 using a custom-built data collection tool.RESULTS: Of the 127 062 individuals screened, 97.2% had a valid CAD4TB score; 11 184 (9.1%) individuals had a CAD4TB score ≥70. Prevalence of Xpert positivity rose from 0.7% in the <50 category to 23.5% in the >90 category. The strong linear association between CAD4TB score and Xpert positivity was found in both community and hospital settings.CONCLUSION: The strong association between CAD4TB scores and Xpert positivity provide evidence that an ACR-based pre-screening performs well when implemented at scale in a high-burden setting.

scholarly journals Galactic plane structure in hard X-rays

2009 ◽  
Vol 5 (H15) ◽  
pp. 809-809
Author(s):  
A. Lutovinov ◽  
M. Revnivtsev ◽  
R. Krivonos
Keyword(s):  
Energy Band ◽  
Galactic Plane ◽  
Galactic Disk ◽  
X Rays ◽  
X Ray ◽  
The Galaxy ◽  
Increased Sensitivity ◽  
Using Data

AbstractWe study the structure of the Galaxy in the hard X-ray energy band (¿20 keV) using data from the INTEGRAL observatory. The increased sensitivity of the survey and the very deep observations performed during six years of the observatory operation allow us to detect about a hundred new sources. This significantly enlarges the sample of hard X-ray sources in the Galactic disk and bulge in a comparison with the previous studies.

scholarly journals Comparing image analysis approaches versus expert readers: the relation of knee radiograph features to knee pain

2018 ◽  
Vol 77 (11) ◽  
pp. 1606-1609 ◽  
Author(s):  
Luca Minciullo ◽  
Matthew J Parkes ◽  
David T Felson ◽  
Timothy F Cootes
Keyword(s):  
Image Analysis ◽  
Knee Pain ◽  
Area Under The Curve ◽  
Automated System ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Radiographic Features ◽  
Random Forest Models ◽  
Using Data

ObjectivesThe relationship between radiographic evidence of osteoarthritis and knee pain has been weak. This may be because features that best discriminate knees with pain have not been included in analyses. We tested the correlation between knee pain and radiographic features taking into account both image analysis features and manual scores.MethodsUsing data of the Multicentre Osteoarthritis Study, we tested in a cross-sectional design how well X-ray features discriminated those with frequent knee pain (one question at one time) or consistent frequent knee pain (three questions at three times during the 2 weeks prior to imaging) from those without it. We trained random forest models on features from two radiographic views for classification.ResultsX-rays were better at classifying those with pain using three questions compared with one. When we used all manual radiographic features, the area under the curve (AUC) was 73.9%. Using the best model from automated image analyses or a combination of these and manual grades, no improvement over manual grading was found.ConclusionsX-ray changes of OA are more strongly associated with repeated reports of knee pain than pain reported once. In addition, a fully automated system that assessed features not scored on X-ray performed no better than manual grading of features.

scholarly journals Development of a lung segmentation algorithm for analog imaged chest X-Ray: preliminary results

2021 ◽  
Author(s):  
Matheus A. Renzo ◽  
Natália Fernandez ◽  
André A. Baceti ◽  
Natanael Nunes Moura Junior ◽  
André Anjos
Keyword(s):  
Semantic Segmentation ◽  
X Rays ◽  
Computer Aided Detection ◽  
Segmentation Evaluation ◽  
Lung Segmentation ◽  
X Ray ◽  
Chest X Ray ◽  
Digitized Images ◽  
Public Datasets ◽  
The Impact

Analog X-Ray radiography is still used in many underdeveloped regions around the world. To allow these populations to benefit from advances in automatic computer-aided detection (CAD) systems, X-Ray films must be digitized. Unfortunately, this procedure may introduce artefacts which may severely impair the performance of such systems. This work investigates the impact digitized images may cause to deep neural networks trained for lung (semantic) segmentation on digital x-ray samples. While three public datasets for lung segmentation evaluation exist for digital samples, none are available for digitized data. To this end, a U-Net architecture was trained on publicly available data, and used to predict lung segmentation on a newly annotated set of digitized images. Our results show that the model is capable to effectively identify lung segmentation at digital X-Rays with a high intra-dataset (PR AUC: 0.99) and cross-dataset (PR AUC: 0.99) performances on unseen test data. When challenged against analog imaged films, the performance is substantially degraded (PR AUC: 0.90). Our analysis further suggests that the use of maximum F1 and precision-recall AUC (PR AUC) measures are not informative to identify segmentation problems in images.

scholarly journals Chest X-ray scanning based detection of COVID-19 using deepconvolutional neural network

2020 ◽  
Author(s):  
Samir Yadav ◽  
Jasminder Kaur Sandhu ◽  
Yadunath Pathak ◽  
Shivajirao Jadhav
Keyword(s):  
Neural Network ◽  
Low Cost ◽  
Diagnostic System ◽  
Multiclass Classification ◽  
Expert Advice ◽  
X Rays ◽  
X Ray ◽  
Chest X Ray ◽  
Using Data ◽  
Life On Earth

Abstract Everyone’s life on earth influenced by a global coronavirus outbreak COVID- 19. Two regular practices, pathology tests, and Computer Tomography (CT) scan used to diagnose COVID-19. Pathology tests produce a considerable amount of false-positives & are time-consuming, whereas CT scans tests are costly and require expert advice. Hence, the main aim of this work is to develop a fast, accurate, and low-cost diagnostic system for detection of COVID-19 using inexpensive chest X-rays and the modern Deep Convolutional Neural Network(CNN) approach to assist medical professionals. In this study, two pre-trained CNN models (VGG16 and InceptionV3) are evaluated by several experiments using data augmentations. The analysis is based on 2905 images of chest X-rays with 219 confirmed positive COVID-19 and 1345 positive pneumonia cases taken from the open-source database consisting of patients suffering from the COVID-19 disease. Since a database consists of multiple types of diseases, multiclass classification for diagnosis of COVID-19 is used. The InceptionV3 model provides the highest classification accuracy (99.35% and 98.29%) for two binary classifications (normal vs. COVID-19 and COVID- 19 vs. Pneumonia) compare to VGG16 model’s accuracy (97.71% and 96.27%). Whereas, VGG16 provides highest accuracy (98.84%)for multiclass-classification(normal vs COVID- 19 vs pneumonia) as compared to VGG16 model’s accuracy(96.35%).

scholarly journals LOW-POWER SOLAR FLARES OF OPTICAL AND X-RAY WAVELENGTHS FOR SOLAR CYCLES 21–24

2020 ◽  
Vol 6 (3) ◽  
pp. 18-25
Author(s):  
Aleksandr Borovik ◽  
Anton Zhdanov
Keyword(s):  
Solar Activity ◽  
Low Power ◽  
Solar Flares ◽  
Optical Emission ◽  
Flare Activity ◽  
X Rays ◽  
Solar Cycles ◽  
X Ray ◽  
Cycle 24 ◽  
Using Data

Using data obtained in optical and X-ray wavelengths, we have analyzed solar flare activity for cycles 21–24. Over the last three cycles, solar activity is shown to decrease significantly. As compared to solar cycle 21 (the most active over the last 50 years), in cycle 24 2–4-class large optical flares are 4.4 times rarer; 1-class flares, 8.2 times; and S-class small flares, 4.1 times. The number of X-class flares decreased 3.7 times; M-class flares, 3.2 times. This confirms that secular solar activity trends affect peak values of 11-year cycles. It is shown that optical low-power flares can be accompanied by proton fluxes and X-ray bursts of different intensity, including X-class ones. Ranges of small flare emission in soft X-rays largely overlap with emission ranges of flares of high optical classes. We have confirmed that X-ray emission from solar flares appears on average 2 min before the optical emission. The X-ray maximum for small optical flares and 1-class flares occurs approximately 1 min later; for 2–4-class flares, 2 min.

scholarly journals Revisiting the spectral and timing properties of 4U 1909+07 with NuSTAR and Astrosat

2020 ◽  
Vol 498 (4) ◽  
pp. 4830-4838 ◽  
Author(s):  
Gaurava K Jaisawal ◽  
Sachindra Naik ◽  
Wynn C G Ho ◽  
Neeraj Kumari ◽  
Prahlad Epili ◽  
...  
Keyword(s):  
Broad Band ◽  
High Energy ◽  
High Mass ◽  
X Rays ◽  
Pulse Profile ◽  
X Ray ◽  
Beam Geometry ◽  
Cyclotron Absorption ◽  
Using Data ◽  
Wind Distribution

ABSTRACT We present the results obtained from the analysis of high-mass X-ray binary pulsar 4U 1909+07 using NuSTAR and Astrosat observations in July 2015 and 2017, respectively. X-ray pulsations at ≈604 s are clearly detected in our study. Based on the long-term spin-frequency evolution, the source is found to spun-up in the last 17 yr. We observed a strongly energy-dependent pulse profile that evolved from a complex broad structure in soft X-rays into a profile with a narrow emission peak followed by a plateau in energy ranges above 20 keV. This behaviour ensured a positive correlation between the energy and pulse fraction. The pulse profile morphology and its energy evolution are almost similar during both the observations, suggesting a persistent emission geometry of the pulsar over time. The broad-band energy spectrum of the pulsar is approximated by an absorbed high-energy exponential cut-off power-law model with iron emission lines. In contrast to the previous report, we found no statistical evidence for the presence of cyclotron absorption features in the X-ray spectra. We performed phase-resolved spectroscopy using data from the NuSTAR observation. Our results showed a clear signature of absorbing material at certain pulse phases of the pulsar. These findings are discussed in terms of stellar wind distribution and its effect on the beam geometry of this wind-fed accreting neutron star. We also reviewed the subsonic quasi-spherical accretion theory and its implication on the magnetic field of 4U 1909+07 depending on the global spin-up rate.

Dual-Ray Net: Automatic Diagnosis of Thoracic Diseases Using Frontal and Lateral Chest X-rays

2020 ◽  
Vol 10 (2) ◽  
pp. 348-355
Author(s):  
Xin Huang ◽  
Yu Fang ◽  
Mingming Lu ◽  
Fengqi Yan ◽  
Jun Yang ◽  
...  
Keyword(s):  
Chest Radiography ◽  
Feature Fusion ◽  
Small Data ◽  
Data Sets ◽  
X Rays ◽  
X Ray ◽  
Comparison Results ◽  
Chest Disease ◽  
Chest X Ray ◽  
Lateral Chest

Computer-aided diagnosis (CAD) is an important work which can improve the working efficiency of physicians. With the availability of large-scale data sets, several methods have been proposed to classify pathology on chest X-ray images. However, most methods report performance based on a frontal chest radiograph, ignoring the effect of the lateral chest radiography on the diagnosis. This paper puts forward a kind of model, Dual-Ray Net, of a deep convolutional neural network which can deal with the front and lateral chest radiography at the same time by referring the method of using lateral chest radiography to assist diagnose during the diagnosis used by radiologists. Firstly, we evaluated the performance of parameter migration to small data after pre-training for large datasets. The data sets for pre-training are chest X-ray 14 and ImageNet respectively. The results showed that pre-training with chest X-ray 14 performed better than with the generic dataset ImageNet. Secondly, We evaluated the performance of the Frontal and lateral chest radiographs in different modes of input model for the diagnosis of assisted chest disease. Finally, by comparing different feature fusion methods of addition and concatenation, we found that the fusion effect of concatenation is better, which average AUC reached 0.778. The comparison results show that whether it is a public or a non-public dataset, our Dual-Ray Net (concatenation) architecture shows improved performance in recognizing findings in CXR images when compared to applying separate baseline frontal and lateral classes.

scholarly journals LOW-POWER SOLAR FLARES OF OPTICAL AND X-RAY WAVELENGTHS FOR SOLAR CYCLES 21–24

2020 ◽  
Vol 6 (3) ◽  
pp. 16-22
Author(s):  
Aleksandr Borovik ◽  
Anton Zhdanov
Keyword(s):  
Solar Activity ◽  
Low Power ◽  
Solar Flares ◽  
Optical Emission ◽  
Flare Activity ◽  
X Rays ◽  
Solar Cycles ◽  
X Ray ◽  
Cycle 24 ◽  
Using Data

Using data obtained in optical and X-ray wavelengths, we have analyzed solar flare activity for cycles 21–24. Over the last three cycles, solar activity is shown to decrease significantly. As compared to solar cycle 21 (the most active over the last 50 years), in cycle 24 2–4-class large optical flares are 4.4 times rarer; 1-class flares, 8.2 times; and S-class small flares, 4.1 times. The number of X-class flares decreased 3.7 times; M-class flares, 3.2 times. This confirms that secular solar activity trends affect peak values of 11-year cycles. It is shown that optical low-power flares can be accompanied by proton fluxes and X-ray bursts of different intensity, including X-class ones. Ranges of small flare emission in soft X-rays largely overlap with emission ranges of flares of high optical classes. We have confirmed that X-ray emission from solar flares appears on average 2 min before the optical emission. The X-ray maximum for small optical flares and 1-class flares occurs approximately 1 min later; for 2–4-class flares, 2 min.

scholarly journals Identifying barriers and facilitators to implementation of community-based tuberculosis active case finding with mobile X-ray units in Lima, Peru: a RE-AIM evaluation

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e050314
Author(s):  
Courtney M Yuen ◽  
Daniela Puma ◽  
Ana Karina Millones ◽  
Jerome T Galea ◽  
Christine Tzelios ◽  
...  
Keyword(s):  
Chest Radiography ◽  
Treatment Initiation ◽  
Implementation Fidelity ◽  
Barriers And Facilitators ◽  
Secondary Outcome ◽  
X Rays ◽  
Mobile Unit ◽  
Tuberculosis Case ◽  
X Ray ◽  
Testing Procedures

ObjectivesIdentify barriers and facilitators to integrating community tuberculosis screening with mobile X-ray units into a health system.MethodsReach, effectiveness, adoption, implementation and maintenance evaluation.Setting3-district region of Lima, Peru.Participants63 899 people attended the mobile units from 7 February 2019 to 6 February 2020.InterventionsParticipants were screened by chest radiography, which was scored for abnormality by computer-aided detection. People with abnormal X-rays were evaluated clinically and by GeneXpert MTB/RIF (Xpert) sputum testing. People diagnosed with tuberculosis at the mobile unit were accompanied to health facilities for treatment initiation.Primary and secondary outcome measuresReach was defined as the percentage of the population of the three-district region that attended the mobile units. Effectiveness was defined as the change in tuberculosis case notifications over a historical baseline. Key implementation fidelity indicators were the percentages of people who had chest radiography performed, were evaluated clinically, had sputum samples collected, had valid Xpert results and initiated treatment.ResultsThe intervention reached 6% of the target population and was associated with an 11% (95% CI 6 to 16) increase in quarterly case notifications, adjusting for the increasing trend in notifications over the previous 3 years. Implementation indicators for screening, sputum collection and Xpert testing procedures all exceeded 85%. Only 82% of people diagnosed with tuberculosis at the mobile units received treatment; people with negative or trace Xpert results were less likely to receive treatment. Suboptimal treatment initiation was driven by health facility doctors’ lack of familiarity with Xpert and lack of confidence in diagnoses made at the mobile unit.ConclusionMobile X-ray units were a feasible and effective strategy to extend tuberculosis diagnostic services into communities and improve early case detection. Effective deployment however requires advance coordination among stakeholders and targeted provider training to ensure that people diagnosed with tuberculosis by new modalities receive prompt treatment.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

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