Window width/window level (ct)

2020 ◽  
Author(s):  
G. Tempelman
Keyword(s):  
Window Width ◽  
Window Level

Window width/window level

2018 ◽  
pp. 107-114
Author(s):  
Gert Tempelman
Keyword(s):  
Window Width ◽  
Window Level

Effects of window width and window level adjustment on detection tasks in computed tomography images

2017 ◽  
Author(s):  
P. Khobragade ◽  
Jiahua Fan ◽  
Franco Rupcich ◽  
Dominic J. Crotty ◽  
Taly Gilat Schmidt
Keyword(s):  
Computed Tomography ◽  
Window Width ◽  
Computed Tomography Images ◽  
Window Level

Influence of CT Window Techniques on Gross Tumor Volume Delineation of Lung Cancer

2011 ◽  
Vol 271-273 ◽  
pp. 973-977
Author(s):  
Juan Wang ◽  
Hui Qun Wu ◽  
Jian Guo Xia ◽  
Le Min Tang
Keyword(s):  
Lung Cancer ◽  
Gross Tumor Volume ◽  
Tumor Volume ◽  
Ct Images ◽  
Window Width ◽  
Volume Delineation ◽  
Window Level

To determine the variation in delineation of the gross tumor volume(GTV) of lung cancer on CT images with different window width(WW) and window level(WL).

scholarly journals Influence of windowing and metal artefact reduction algorithms on the volumetric dimensions of five different high-density materials: a cone-beam CT study

2020 ◽  
Vol 49 (8) ◽  
pp. 20200039
Author(s):  
Fernanda Coelho-Silva ◽  
Luciano Augusto Cano Martins ◽  
Daniela Azeredo Braga ◽  
Eliana Zandonade ◽  
Francisco Haiter-Neto ◽  
...  
Keyword(s):  
High Density ◽  
Experimental Conditions ◽  
Metal Artefact Reduction ◽  
Large Window ◽  
Window Width ◽  
Gutta Percha ◽  
Metal Artefact ◽  
Artefact Reduction ◽  
Almost All ◽  
Window Level

Objective: To assess the influence of windowing and metal artefact reduction (MAR) algorithms on the volumetric dimensions of high-density materials using two CBCT systems. Methods: Four cylinders of amalgam, cobalt-chromium, gutta-percha, titanium and zirconium, were manufactured and their physical volumes (PV) were measured. A polymethyl methacrylate phantom containing the cylinders was submitted to CBCT acquisitions with Picasso Trio and OP300 units with their MAR enabled and disabled. The tomographic volume (TV) of all the cylinders was obtained by semi-automatic segmentation using two windowing adjustments: W1—large window width and upper window level; W2—narrow window width and low window level. Volumetric distortion was expressed as the difference between TV and PV. Statistics comprised intraclass correlation coefficient (ICC) and analysis of variance (ANOVA) for repeated measures with Tukey post hoc test (α = 5%). Results: The ICC values ​​indicated excellent reproducibility of TV. Gutta-percha and titanium resulted in the smallest volumetric distortion. Using W1 provided less volumetric distortion for almost all experimental conditions (p < 0.05). Activating MAR algorithm of Picasso Trio underestimated gutta-percha and titanium TV (p < 0.05) and was inefficient in significantly reducing the volumetric distortion of the other materials (p > 0.05). Disabling MAR algorithm of OP300 resulted in smaller volumetric distortion for almost all experimental conditions (p < 0.05). Conclusions: The TV of gutta-percha and titanium were closer to the PV. In general, the MAR algorithms of both systems were inefficient in significantly reducing the volumetric distortion of high-density materials. We encourage the use of large window width and upper window level to evaluate high-density materials.

scholarly journals Towards Including Dynamic Vegetation Parameters in the EUMETSAT H SAF ASCAT Soil Moisture Products

2021 ◽  
Vol 13 (8) ◽  
pp. 1463
Author(s):  
Susan C. Steele-Dunne ◽  
Sebastian Hahn ◽  
Wolfgang Wagner ◽  
Mariette Vreugdenhil
Keyword(s):  
Soil Moisture ◽  
Interannual Variability ◽  
Incidence Angle ◽  
Pearson Correlation ◽  
The United States ◽  
Research Network ◽  
Window Width ◽  
High Frequency Variability ◽  
Vegetation Parameters ◽  
The Impact

The TU Wien Soil Moisture Retrieval (TUW SMR) approach is used to produce several operational soil moisture products from the Advanced Scatterometer (ASCAT) on the Metop series of satellites as part of the EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H SAF). The incidence angle dependence of backscatter is described by a second-order Taylor polynomial, the coefficients of which are used to normalize ASCAT observations to the reference incidence angle of 40∘ and for correcting vegetation effects. Recently, a kernel smoother was developed to estimate the coefficients dynamically, in order to account for interannual variability. In this study, we used the kernel smoother for estimating these coefficients, where we distinguished for the first time between their two uses, meaning that we used a short and fixed window width for the backscatter normalisation while we tested different window widths for optimizing the vegetation correction. In particular, we investigated the impact of using the dynamic vegetation parameters on soil moisture retrieval. We compared soil moisture retrievals based on the dynamic vegetation parameters to those estimated using the current operational approach by examining their agreement, in terms of the Pearson correlation coefficient, unbiased RMSE and bias with respect to in situ soil moisture. Data from the United States Climate Research Network were used to study the influence of climate class and land cover type on performance. The sensitivity to the kernel smoother half-width was also investigated. Results show that estimating the vegetation parameters with the kernel smoother can yield an improvement when there is interannual variability in vegetation due to a trend or a change in the amplitude or timing of the seasonal cycle. However, using the kernel smoother introduces high-frequency variability in the dynamic vegetation parameters, particularly for shorter kernel half-widths.

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