scholarly journals Improving the quantitative classification of Erlenmeyer flask deformities

2020 ◽  
Vol 50 (2) ◽  
pp. 361-369
Author(s):  
Gautam Adusumilli ◽  
◽  
Joshua D. Kaggie ◽  
Simona D’Amore ◽  
Timothy M. Cox ◽  
...  
Keyword(s):  
Volume Ratio ◽  
Weighted Kappa ◽  
Classification Systems ◽  
Ratio Method ◽  
Point System ◽  
Point Scale ◽  
Erlenmeyer Flask ◽  
Quantitative Classification ◽  
Receiver Operating Characteristic Curves ◽  
Severity Classification

AbstractThe Erlenmeyer flask deformity is a common skeletal modeling deformity, but current classification systems are binary and may restrict its utility as a predictor of associated skeletal conditions. A quantifiable 3-point system of severity classification could improve its predictive potential in disease. Ratios were derived from volumes of regions of interests drawn in 50 Gaucher’s disease patients. ROIs were drawn from the distal physis to 2 cm proximal, 2 cm to 4 cm, and 4 cm to 6 cm. Width was also measured at each of these boundaries. Two readers rated these 100 femurs using a 3-point scale of severity classification. Weighted kappa indicated reliability and one-way analysis of variance characterized ratio differences across the severity scale. Accuracy analyses allowed determination of clinical cutoffs for each ratio. Pearson’s correlations assessed the associations of volume and width with a shape-based concavity metric of the femur. The volume ratio incorporating the metaphyseal region from 0 to 2 cm and the diametaphyseal region at 4–6 cm was most accurate at distinguishing femurs on the 3-point scale. Receiver operating characteristic curves for this ratio indicated areas of 0.95 to distinguish normal and mild femurs and 0.93 to distinguish mild and severe femurs. Volume was moderately associated with the degree of femur concavity. The proposed volume ratio method is an objective, proficient method at distinguishing severities of the Erlenmeyer flask deformity with the potential for automation. This may have application across diseases associated with the deformity and deficient osteoclast-mediated modeling of growing bone.

scholarly journals A Ratio Method for Calculating Stem Volume to Variable Merchantable Limits, and Associated Taper Equations

1988 ◽  
Vol 64 (1) ◽  
pp. 18-26 ◽  
Author(s):  
I. S. Alemdag
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Independent Set ◽  
Volume Ratio ◽  
Tree Height ◽  
Ratio Method ◽  
Stem Volume ◽  
Statistical Measures ◽  
Fit Index ◽  
Taper Equations

One method for estimating the volume of the merchantable portion of a tree stem is the volume ratio method. In this study the ratio used with this method was derived from another ratio expressed as ground-to-limit volume to total stem volume. Because of the latter ratio's strong correlation with the ratio of merchantable top diameter/breast height diameter and merchantable height/total tree height, several mathematical models were formed employing these variables for its estimation for red pine (Pinus resinosa Ait.) and sugar maple (Acer saccharum Marsh.). Among the models that were tested, the best for each variable was chosen by assessing its adequacy by the statistical measures of fit index and standard error of estimate. When checked against an independent set of data, these best models performed satisfactorily, with small overall biases. Furthermore, taper equations were derived from these ground-to-limit volume ratio equations.

Comparison of subjective and fully automated methods for measuring mammographic density

2017 ◽  
Vol 59 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Nataliia Moshina ◽  
Marta Roman ◽  
Sofie Sebuødegård ◽  
Gunvor G Waade ◽  
Giske Ursin ◽  
...  
Keyword(s):  
Mammographic Density ◽  
Breast Density ◽  
Screening Program ◽  
Weighted Kappa ◽  
Screening Mammography ◽  
Point Scale ◽  
Mean Values ◽  
Automated Method ◽  
Cancer Screening Program ◽  
Density Assessment

Background Breast radiologists of the Norwegian Breast Cancer Screening Program subjectively classified mammographic density using a three-point scale between 1996 and 2012 and changed into the fourth edition of the BI-RADS classification since 2013. In 2015, an automated volumetric breast density assessment software was installed at two screening units. Purpose To compare volumetric breast density measurements from the automated method with two subjective methods: the three-point scale and the BI-RADS density classification. Material and Methods Information on subjective and automated density assessment was obtained from screening examinations of 3635 women recalled for further assessment due to positive screening mammography between 2007 and 2015. The score of the three-point scale (I = fatty; II = medium dense; III = dense) was available for 2310 women. The BI-RADS density score was provided for 1325 women. Mean volumetric breast density was estimated for each category of the subjective classifications. The automated software assigned volumetric breast density to four categories. The agreement between BI-RADS and volumetric breast density categories was assessed using weighted kappa (kw). Results Mean volumetric breast density was 4.5%, 7.5%, and 13.4% for categories I, II, and III of the three-point scale, respectively, and 4.4%, 7.5%, 9.9%, and 13.9% for the BI-RADS density categories, respectively ( P for trend < 0.001 for both subjective classifications). The agreement between BI-RADS and volumetric breast density categories was kw = 0.5 (95% CI = 0.47–0.53; P < 0.001). Conclusion Mean values of volumetric breast density increased with increasing density category of the subjective classifications. The agreement between BI-RADS and volumetric breast density categories was moderate.

scholarly journals Study on stress simulation of concrete floor on transversely isotropic equivalent pile foundation during construction period

2019 ◽  
Vol 275 ◽  
pp. 03005
Author(s):  
Min Yuan ◽  
Sheng Qiang ◽  
Minjie Hu ◽  
Yedong Zhang ◽  
Hongdan Wang
Keyword(s):  
Numerical Simulation ◽  
Elastic Modulus ◽  
Calculation Result ◽  
Pile Foundation ◽  
Volume Ratio ◽  
Transversely Isotropic ◽  
Ratio Method ◽  
Calculation Error ◽  
Construction Period ◽  
Concrete Floor

In the concrete pouring process of large pumping stations, the pile foundation plays an important role in supporting the upper structures, and also has a certain constraint on the concrete floor. In the numerical simulation calculation of construction period, to simplify the pre-processing, the volume ratio method is sometimes applied to regard the pile and surrounding soil foundation as the equivalent pile foundation, while the anisotropy of pile foundation is ignored, which will result in large calculation error of the horizontal stress of the concrete floor. Aiming at this problem, the anisotropy theory of materials is adopted in this paper to simulate the temperature field and stress field of the concrete floor both on non-equivalent pile foundation and equivalent pile foundation during construction period after compiling corresponding calculation program. The results show that when the ratio α of the horizontal elastic modulus to the vertical elastic modulus of equivalent pile foundation is about 1/20, the calculation result of the transversely isotropic equivalent pile foundation is approximately equal to the calculation result of the non-equivalent pile foundation (exact solution). It may provide some reference to similar engineering numerical simulation.

scholarly journals The accuracy of teleradiologists in diagnosing COVID-19 based on a French multicentric emergency cohort

2020 ◽  
Author(s):  
Hubert Nivet ◽  
Amandine Crombé ◽  
Paul Schuster ◽  
Thomas Ayoub ◽  
Laurent Pourriol ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Weighted Kappa ◽  
Kappa Coefficient ◽  
Chest Ct ◽  
Observer Agreement ◽  
Rt Pcr ◽  
Point Scale ◽  
High Diagnostic Accuracy ◽  
Typical Appearance ◽  
Pcr Test

Abstract Objectives: To evaluate the accuracy of diagnoses of COVID-19 based on chest CT as well as inter-observer agreement between teleradiologists during on-call duty and senior radiologists in suspected COVID-19 patients. Materials and Methods: From 03/13/2020 to 04/14/2020, consecutive suspected COVID-19 adult patients who underwent both an RT-PCR test and chest CT from 15 hospitals were included in this prospective study. Chest CTs were immediately interpreted by the on-call teleradiologist and were systematically blind reviewed by a senior radiologist. Readings were categorised using a five-point scale: (1) normal; (2) non-infectious findings; (3) infectious findings but not consistent with COVID-19 infection; (4) consistent with COVID-19 infection; and (5) typical appearance of COVID-19 infection. The diagnostic accuracy of chest CT and inter-observer agreement using the Kappa coefficient were evaluated over the study period.Results: In total, 513 patients were enrolled, of whom 244/513 (47.6%) tested positive for RT-PCR. First readings were scored 4 or 5 in 225/244 (92%) RT-PCR+ patients, and between 1 and 3 in 201/269 (74.7%) RT-PCR- patients. The data were highly consistent (weighted Kappa=0.87) and correlated with RT-PCR (p<0.001, AUC1st-reading=0.89, AUC2nd-reading=0.93). The negative predictive value for scores of 4 or 5 was 0.91–0.92, and the PPV for a score of 5 was 0.89–0.96 at the first and second readings, respectively. Diagnostic accuracy was consistent over the study period, irrespective of a variable prevalence rate.Conclusion: Chest CT demonstrated high diagnostic accuracy with strong inter-observer agreement between on-call teleradiologists with varying degrees of experience and senior radiologists over the study period.

scholarly journals Comparison of Visual Field Severity Classification Systems for Glaucoma

2012 ◽  
Vol 21 (8) ◽  
pp. 551-561 ◽  
Author(s):  
Minna Ng ◽  
Pamela A. Sample ◽  
John P. Pascual ◽  
Linda M. Zangwill ◽  
Chris A. Girkin ◽  
...  
Keyword(s):  
Visual Field ◽  
Classification Systems ◽  
Severity Classification

scholarly journals Mapping and characterization of intensity in land use by pasture using remote sensing

2019 ◽  
Vol 23 (5) ◽  
pp. 352-358
Author(s):  
Arthur T. Calegario ◽  
Luis F. Pereira ◽  
Silvio B. Pereira ◽  
Laksme N. O. da Silva ◽  
Uriel L. de Araújo ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Weighted Kappa ◽  
Classification Systems ◽  
Land Use Classification ◽  
Livestock Farming ◽  
Climatic Characteristics ◽  
Degree Of Degradation ◽  
Degraded Pastures

ABSTRACT The current demand for food has been met through the exploitation of natural reserves. Brazil has 26% of its extension occupied by agricultural uses, 62% of which are pastures. Degraded pastures have greater land use intensity than well-managed pastures, leading to greater degradation of the environment. Land use classification systems consider that pastures are well managed, a misconception for the Brazilian reality. Based on this approach, it was aimed to develop a methodology for mapping the intensity of land use by pasture via remote sensing. The method of mapping was developed and validated in basins with different soil and climatic characteristics. Three calibrations were performed based on NDVI values to ascertain the influence on the results, being evaluated from the field campaigns and the kappa and weighted kappa indices. The kappa and weighted kappa indices presented reasonable and moderate agreement, respectively. The results were considered as satisfactory for the three calibrations, evidencing that the degree of degradation of the pastures can be estimated in a simple way by remote sensing. The Limoeiro River Basin has around 46.9% of pastures, at least, heavily degraded and 96.6% with some degree of degradation, which contributes to degradation of the natural resources and reduction of livestock farming and economic potential of the basin.

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