Trust in data‐requesting organizations—A quantitative analysis on cultural antecedents and individual‐level perceptions

Abstract Purpose: Digital PET cameras markedly improve sensitivity and spatial resolution of brain 18F-FDG PET images compared to conventional cameras. Our study aimed to assess whether specific control databases are required to improve the diagnostic performance of these recent advances.Methods: We retrospectively selected two groups of subjects, twenty-seven Alzheimer's Disease (AD) patients and twenty-two healthy control (HC) subjects. All subjects underwent a brain 18F-FDG PET on a digital camera (Vereos, Philips®). These two group (AD and HC) are compared, using a Semi-Quantitative Analysis (SQA), to two age and sex matched controls acquired with a digital PET/CT (Vereos, Philips®) or a conventional PET/CT (Biograph 6, Siemens®) camera, at group and individual levels. Moreover, individual visual interpretation of SPM T-maps was provided for the positive diagnosis of AD by 3 experienced raters.Results: At group level, SQA using digital controls detected more marked hypometabolic areas in AD (+ 116 cm3 at p<0.001 uncorrected for the voxel, corrected for the cluster) than SQA using conventional controls. At the individual level, the accuracy of SQA for discriminating AD using digital controls was higher than SQA using conventional controls (86 % vs. 80 %, p<0.01, at p<0.005 uncorrected for the voxel, corrected for the cluster), with similar specificity (82 % vs. 82 %) but higher sensitivity (89 % vs. 78 %). These results were confirmed by visual analysis (accuracies of 84 % and 82 % for digital and conventional controls respectively, p=0.01).Conclusion: There is an urgent need to establish specific digital PET control databases for SQA of brain 18F-FDG PET images as such databases improve the accuracy of AD diagnosis.

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Accuracy of FDG-PET at the individual level in MCI-LB versus MCI-AD: A stepwise approach from visual to semi-quantitative analysis

Journal of the Neurological Sciences ◽

10.1016/j.jns.2021.117830 ◽

2021 ◽

Vol 429 ◽

pp. 117830

Author(s):

Federico Massa ◽

Andrea Chincarini ◽

Matteo Bauckneht ◽

Stefano Raffa ◽

Enrico Peira ◽

...

Keyword(s):

Quantitative Analysis ◽

Fdg Pet ◽

Stepwise Approach ◽

Individual Level ◽

The Individual

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To Purge or Not to Purge? An Individual-Level Quantitative Analysis of Elite Purges in Dictatorships

British Journal of Political Science ◽

10.1017/s0007123421000569 ◽

2021 ◽

pp. 1-19

Author(s):

Edward Goldring ◽

Austin S. Matthews

Keyword(s):

Quantitative Analysis ◽

First Generation ◽

Empirical Support ◽

Individual Level

Abstract Why do dictators purge specific elites but not others? And why do dictators purge these elites in certain ways? Examining these related questions helps us understand not only how dictators retain sufficient competence in their regimes to alleviate popular and foreign threats, but also how dictators nullify elite threats. Dictators are more likely to purge first-generation elites, who are more powerful because they can negotiate their role from a position of strength and possess valuable vertical and horizontal linkages with other elites. Further, dictators tend to imprison purged first-generation elites – rather than execute, exile or simply remove them – to avoid retaliation from other elites or the purged elite continuing to sow discord. We find empirical support for our predictions from novel data on autocratic elites in 16 regimes from 1922 to 2020.

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Clinical impact of digital and conventional PET control databases for semi-quantitative analysis of brain 18F-FDG digital PET scans

EJNMMI Research ◽

10.1186/s13550-020-00733-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Elise Mairal ◽

Matthieu Doyen ◽

Thérèse Rivasseau-Jonveaux ◽

Catherine Malaplate ◽

Eric Guedj ◽

...

Keyword(s):

Quantitative Analysis ◽

Fdg Pet ◽

Visual Analysis ◽

Digital Camera ◽

Visual Interpretation ◽

Individual Level ◽

Pet Ct ◽

Digital Pet ◽

Healthy Control ◽

The Individual

Abstract Purpose Digital PET cameras markedly improve sensitivity and spatial resolution of brain 18F-FDG PET images compared to conventional cameras. Our study aimed to assess whether specific control databases are required to improve the diagnostic performance of these recent advances. Methods We retrospectively selected two groups of subjects, twenty-seven Alzheimer's Disease (AD) patients and twenty-two healthy control (HC) subjects. All subjects underwent a brain 18F-FDG PET on a digital camera (Vereos, Philips®). These two group (AD and HC) are compared, using a Semi-Quantitative Analysis (SQA), to two age and sex matched controls acquired with a digital PET/CT (Vereos, Philips®) or a conventional PET/CT (Biograph 6, Siemens®) camera, at group and individual levels. Moreover, individual visual interpretation of SPM T-maps was provided for the positive diagnosis of AD by 3 experienced raters. Results At group level, SQA using digital controls detected more marked hypometabolic areas in AD (+ 116 cm3 at p < 0.001 uncorrected for the voxel, corrected for the cluster) than SQA using conventional controls. At the individual level, the accuracy of SQA for discriminating AD using digital controls was higher than SQA using conventional controls (86% vs. 80%, p < 0.01, at p < 0.005 uncorrected for the voxel, corrected for the cluster), with higher sensitivity (89% vs. 78%) and similar specificity (82% vs. 82%). These results were confirmed by visual analysis (accuracies of 84% and 82% for digital and conventional controls respectively, p = 0.01). Conclusion There is an urgent need to establish specific digital PET control databases for SQA of brain 18F-FDG PET images as such databases improve the accuracy of AD diagnosis.

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Clinical Impact of Digital and Conventional PET Control Databases for Semi-Quantitative Analysis of Brain 18F-FDG Digital PET Scans

10.21203/rs.3.rs-51214/v1 ◽

2020 ◽

Author(s):

Elise Mairal ◽

Matthieu Doyen ◽

Thérèse Rivasseau-Jonveaux ◽

Catherine Malaplate ◽

Eric Guedj ◽

...

Keyword(s):

Quantitative Analysis ◽

Fdg Pet ◽

Visual Analysis ◽

Digital Camera ◽

Visual Interpretation ◽

Individual Level ◽

Lower Specificity ◽

Digital Pet ◽

The Individual ◽

Pet Scans

Abstract Purpose: Digital PET cameras markedly improve sensitivity and spatial resolution of brain 18F-FDG PET images compared to conventional cameras. Our study aimed to assess whether specific control databases are required to improve the diagnostic performance of these recent advances.Methods: We analysed twenty-seven Alzheimer's Disease (AD) patients and twenty-two healthy subjects. These two groups underwent a brain 18F-FDG PET on a digital camera (Vereos, Philips®) with a Semi-Quantitative Analysis (SQA), i.e. comparisons to two age and sex matched controls acquired with a digital PET (Vereos, Philips®) and a conventional PET (Biograph 6, Siemens®) camera, at group and individual levels. Moreover, individual visual interpretation of SPM T-maps was provided for the positive diagnosis of AD by 3 experienced raters.Results: At group level, SQA using digital controls detected more marked hypometabolic areas in AD (+34 mm3 at p<0.001 uncorrected for the voxel, corrected for the cluster) than SQA using conventional controls. At the individual level, accuracy of SQA using digital controls was higher than SQA using conventional controls (82 vs. 63%, p<0.01, at p<0.005 uncorrected for the voxel, corrected for the cluster), with lower specificity (73 vs. 95%) but much higher sensitivity (89 vs. 37%). These results were confirmed by visual analysis (accuracies of 78% and 65% for digital and conventional controls respectively).Conclusion: There is an urgent need to establish specific digital PET control databases for SQA of brain 18F-FDG PET images as such databases improve the accuracy of AD diagnosis.

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Clinical impact of digital and conventional PET control databases for semi-quantitative analysis of brain 18F-FDG digital PET scans

10.21203/rs.3.rs-51214/v3 ◽

2020 ◽

Author(s):

Elise Mairal ◽

Matthieu Doyen ◽

Thérèse Rivasseau-Jonveaux ◽

Catherine Malaplate ◽

Eric Guedj ◽

...

Keyword(s):

Quantitative Analysis ◽

Fdg Pet ◽

Visual Analysis ◽

Digital Camera ◽

Visual Interpretation ◽

Individual Level ◽

Pet Ct ◽

Digital Pet ◽

Healthy Control ◽

The Individual

Abstract Purpose: Digital PET cameras markedly improve sensitivity and spatial resolution of brain 18F-FDG PET images compared to conventional cameras. Our study aimed to assess whether specific control databases are required to improve the diagnostic performance of these recent advances.Methods: We retrospectively selected two groups of subjects, twenty-seven Alzheimer's Disease (AD) patients and twenty-two healthy control (HC) subjects. All subjects underwent a brain 18F-FDG PET on a digital camera (Vereos, Philips®). These two group (AD and HC) are compared, using a Semi-Quantitative Analysis (SQA), to two age and sex matched controls acquired with a digital PET/CT (Vereos, Philips®) or a conventional PET/CT (Biograph 6, Siemens®) camera, at group and individual levels. Moreover, individual visual interpretation of SPM T-maps was provided for the positive diagnosis of AD by 3 experienced raters.Results: At group level, SQA using digital controls detected more marked hypometabolic areas in AD (+ 116 cm3 at p<0.001 uncorrected for the voxel, corrected for the cluster) than SQA using conventional controls. At the individual level, the accuracy of SQA for discriminating AD using digital controls was higher than SQA using conventional controls (86 % vs. 80 %, p<0.01, at p<0.005 uncorrected for the voxel, corrected for the cluster), with higher sensitivity (89 % vs. 78 %) and similar specificity (82 % vs. 82 %). These results were confirmed by visual analysis (accuracies of 84 % and 82 % for digital and conventional controls respectively, p=0.01).Conclusion: There is an urgent need to establish specific digital PET control databases for SQA of brain 18F-FDG PET images as such databases improve the accuracy of AD diagnosis.

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An Improved Quantitative Image Analyser

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078663 ◽

1977 ◽

Vol 35 ◽

pp. 226-227

Author(s):

J.P. Fallon ◽

P.J. Gregory ◽

C.J. Taylor

Keyword(s):

Feature Extraction ◽

Quantitative Analysis ◽

Frequency Content ◽

General Sense ◽

Physical Measurements ◽

Quantitative Image ◽

Image Analyser ◽

Automatic Methods ◽

Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

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Quantification of Silica Uptake by Alveolar Macrophages - An Emperical Scanning Electron Microprobe Method

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100054297 ◽

1982 ◽

Vol 40 ◽

pp. 332-333

Author(s):

V. V. Damiano ◽

R. P. Daniele ◽

H. T. Tucker ◽

J. H. Dauber

Keyword(s):

Quantitative Analysis ◽

Alveolar Macrophages ◽

Bulk Sample ◽

Silica Particles ◽

Empirical Method ◽

Phagocytic Cells ◽

Calibration Standards ◽

X Ray ◽

Accurate Quantitative Analysis ◽

Scanning Electron

An important example of intracellular particles is encountered in silicosis where alveolar macrophages ingest inspired silica particles. The quantitation of the silica uptake by these cells may be a potentially useful method for monitoring silica exposure. Accurate quantitative analysis of ingested silica by phagocytic cells is difficult because the particles are frequently small, irregularly shaped and cannot be visualized within the cells. Semiquantitative methods which make use of particles of known size, shape and composition as calibration standards may be the most direct and simplest approach to undertake. The present paper describes an empirical method in which glass microspheres were used as a model to show how the ratio of the silicon Kα peak X-ray intensity from the microspheres to that of a bulk sample of the same composition correlated to the mass of the microsphere contained within the cell. Irregular shaped silica particles were also analyzed and a calibration curve was generated from these data.

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Lateral resolution of the electron microbeam analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109859 ◽

1978 ◽

Vol 36 (1) ◽

pp. 542-543

Author(s):

H.J. Dudek

Keyword(s):

Quantitative Analysis ◽

Depth Resolution ◽

Lateral Resolution ◽

Cylindrical Particle ◽

Correction Procedure ◽

X Ray ◽

Element Concentrations ◽

Microbeam Analysis ◽

The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

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An example of spectrum imaging used for comparison of EELS quantitative analysis techniques on Al-Li

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008794x ◽

1991 ◽

Vol 49 ◽

pp. 726-727

Author(s):

John A. Hunt

Keyword(s):

Quantitative Analysis ◽

Large Data ◽

Difference Spectrum ◽

Large Data Sets ◽

Foil Thickness ◽

Data Sets ◽

Analysis Techniques ◽

Spectrum Imaging ◽

Normal Spectrum ◽

Electron Energy Loss

Spectrum-imaging is a useful technique for comparing different processing methods on very large data sets which are identical for each method. This paper is concerned with comparing methods of electron energy-loss spectroscopy (EELS) quantitative analysis on the Al-Li system. The spectrum-image analyzed here was obtained from an Al-10at%Li foil aged to produce δ' precipitates that can span the foil thickness. Two 1024 channel EELS spectra offset in energy by 1 eV were recorded and stored at each pixel in the 80x80 spectrum-image (25 Mbytes). An energy range of 39-89eV (20 channels/eV) are represented. During processing the spectra are either subtracted to create an artifact corrected difference spectrum, or the energy offset is numerically removed and the spectra are added to create a normal spectrum. The spectrum-images are processed into 2D floating-point images using methods and software described in [1].

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