scholarly journals Determination of DQE as a quantitative assessment of detectors in digital mammography: Measurements and calculation in practice

2021 ◽  
Vol 27 (3) ◽  
pp. 223-232
Author(s):  
Anna Wysocka-Rabin ◽  
Magdalena Dobrzyńska ◽  
Katarzyna Pasicz ◽  
Witold Skrzyński ◽  
Ewa Fabiszewska
Keyword(s):  
Digital Mammography ◽  
Quality Parameters ◽  
Test Device ◽  
Tube Voltage ◽  
International Standard ◽  
Air Kerma ◽  
Digital Detector ◽  
Quantitative Image ◽  
Tube Exit

Abstract Introduction: Advances in digital detector technology and methods of image presentation in digital mammography now offer the possibility of implementing mathematical assessment methods to quantitative image analysis. The aim of this work was to develop new software to simplify the application of the existing international standard for DQE in digital mammography and show in detail how it can be applied, using a Siemens Mammomat Inspiration as a model. Material and methods: Consistent with the IEC standard a 2 mm Al filter at the tube exit and images in DICOM format as raw data, without applying any additional post-processing were used. Measurements were performed for W/Rh anode/filter combination and different tube voltage values (26 ÷ 34 kV) without any anti-scatter grid. To verify new software doses ranging from 20-600 µGy were used in measurements. Exposure (air kerma) was measured using a calibrated radiation meter (Piranha Black 457, RTI Electronics AB, Sweden). MTF was determined, using an edge test device constructed specifically for this work. Results: It has been demonstrated that with the new software the DQE can be measured with the accuracy required by the international standard IEC 62220-1-2. DQE has been presented as a function of spatial frequency for W/Rh anode/filter combination and different tube voltage. Conclusions: New software was used successfully to analyze image quality parameters for the Siemens Mammomat Inspiration detector. This was done on the basis of an internationally accepted methodology. In the next step, mammographs with different detector types can be compared.

An Improved Quantitative Image Analyser

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.

A quantitative image analysis method for the determination of cocontinuity in polymer blends

1993 ◽  
Vol 51 ◽  
pp. 894-895
Author(s):  
William A. Heeschen
Keyword(s):  
Image Analysis ◽  
Polymer Blends ◽  
Quantitative Measurement ◽  
Morphological Evolution ◽  
Phase Ratio ◽  
Irregular Shapes ◽  
Quantitative Image ◽  
Discrete Domains ◽  
A Domains

Two new morphological measurements based on digital image analysis, CoContinuity and CoContinuity Balance, have been developed and implemented for quantitative measurement of morphology in polymer blends. The morphology of polymer blends varies with phase ratio, composition and processing. A typical morphological evolution for increasing phase ratio of polymer A to polymer B starts with discrete domains of A in a matrix of B (A/B < 1), moves through a cocontinuous distribution of A and B (A/B ≈ 1) and finishes with discrete domains of B in a matrix of A (A/B > 1). For low phase ratios, A is often seen as solid convex particles embedded in the continuous B phase. As the ratio increases, A domains begin to evolve into irregular shapes, though still recognizable as separate domains. Further increase in the phase ratio leads to A domains which extend into and surround the B phase while the B phase simultaneously extends into and surrounds the A phase.

The Frequency of Occurrence of Handwriting Performance Features Used to Predict Whether Questioned Signatures are Simulated

2018 ◽  
Vol 28 ◽  
pp. 35-42
Author(s):  
David Black ◽  
Bryan Found ◽  
Doug Rogers
Keyword(s):  
Large Population ◽  
Quality Parameters ◽  
Frequency Of Occurrence ◽  
Relative Speed ◽  
Simulation Process ◽  
Spatial Features ◽  
And Performance ◽  
Document Examiners ◽  
Line Trace

Forensic Document Examiners (FDEs) examine the physical morphology and performance attributes of a line trace when comparing questioned to specimen handwriting samples for the purpose of determining authorship. Along with spatial features, the elements of execution of the handwriting are thought to provide information as to whether or not a questioned sample is the product of a disguise or simulation process. Line features such as tremor, pen-lifts, blunt beginning and terminating strokes, indicators of relative speed, splicing and touch ups, are subjectively assessed and used in comparisons by FDEs and can contribute to the formation of an opinion as to the validity of a questioned sample of handwriting or signatures. In spite of the routine use of features such as these, there is little information available regarding the relative frequency of occurrence of these features in populations of disguised and simulated samples when compared to a large population of a single individual’s signature. This study describes a survey of the occurrence of these features in 46 disguised signatures, 620 simulated signatures (produced by 31 different amateur forgers) and 177 genuine signatures. It was found that the presence of splices and touch-ups were particularly good predictors of the simulation process and that all line quality parameters were potentially useful contributors in the determination of the authenticity of questioned signatures. Purchase Article - $10

scholarly journals Recatest—A Technique for Qualitative and Quantitative Assessment of Deferment and Degraded PVD Coatings and CVD Layers in the Deformed Area in the Scratch Test

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2625
Author(s):  
Piotr Domanowski ◽  
Marek Betiuk
Keyword(s):  
Scratch Test ◽  
Metallographic Analysis ◽  
Tool Steels ◽  
Test Device ◽  
Coating Structure ◽  
Testing Technique ◽  
Coating Materials ◽  
Qualitative And Quantitative ◽  
Quantitative Parameters

The purpose of the paper is to present a new Recatest testing technique which uses a series of abrasions within a scratch and its innovative application to describe selected quantitative parameters of locally, plastically deformed substrate and coating materials detected on the spherical microsection in the scratch test. The exposed material structures are subject to a metallographic analysis which allows for the determination of the quantitative parameters, which in turn allow for a description of the change in dynamics of the coating structure within the scratch area as a function of load. These parameters include scratch depth (hs), coating thickness (h1), flash height (hoc, hos), depth of intended material (hd), material depth under scratch (hcp), and material depth under coating (hdb). The paper also includes a description of the Recalo test device designed by the authors, which is used to make a series of spherical abrasion traces on the scratch surface. Recalo is dedicated to the Recatest technique. The analysed material was the CrN/CrCN/HS6-5-2, AlCrN -Alcrona-Balinit/D2 coatings deposited on tool steels.

Simultaneous Determination of the Main Constituents of Viscose Spinning Solutions by Visible near Infrared Spectroscopy

1997 ◽  
Vol 5 (3) ◽  
pp. 135-148 ◽  
Author(s):  
S. Sollinger ◽  
M. Voges
Keyword(s):  
Near Infrared ◽  
Quality Parameters ◽  
Spectroscopic Technique ◽  
Cellulose Content ◽  
Careful Monitoring ◽  
Cellulose Fibres ◽  
Chemical Determination ◽  
Analytical Procedures ◽  
Product Control

The production of cellulose fibres by wet fibres spinning requires a careful monitoring of the spinning bath and especially the spinning solution in terms of product control and for quality assurance purposes. The chemical composition as well as the ripening of the spinning solution are of major importance for maintaining a constant product quality. The conventional determination of the quality parameters of the viscose spinning solution are rather time- and labour-intensive due to the fact that several independent analytical procedures are involved which score low in time efficiency themselves. Briefly, the complete characterisation of the spinning solution requires an iodometric titration of the cellulose xanthogenate (γ-number), an acidimetric titration of the sodium hydroxide (NaOH) content, a UV-VIS spectroscopic determination of the trithiocarbonate (TTC) content and a time-consuming gravimetric cellulose content determination. Sometimes, also, a colloid chemical determination of the degree of ripening (Hottenroth number) is performed in the plant control laboratory. With this work, an approach will be demonstrated, which enables the substitution of these numerous analytical procedures by a single and time-efficient method—a VIS-NIR spectroscopic technique. Therefore, it is possible to determine the parameters: NaOH, TTC, cellulose xanthogenate content and the cellulose content of the viscose spinning solution simultaneously with a reasonable precision within a few minutes.

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