Impact of heel effect and ROI size on the determination of contrast-to-noise ratio for digital mammography systems

2008 ◽  
Author(s):  
Abdulaziz Alsager ◽  
Kenneth C. Young ◽  
Jennifer M. Oduko
Keyword(s):  
Digital Mammography ◽  
Noise Ratio ◽  
Heel Effect

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

scholarly journals Anode heel effect application with step wedge against effect of signal to noise ratio in computed radiography

2020 ◽  
Vol 4 (3) ◽  
pp. 75-82
Author(s):  
Ni Nyoman Ratini ◽  
I Made Yuliara ◽  
Windaryoto Windaryoto
Keyword(s):  
Computed Radiography ◽  
Signal To Noise Ratio ◽  
Pearson Correlation ◽  
P Value ◽  
Signal To Noise ◽  
Correlation Test ◽  
Pearson Correlation Test ◽  
R Value ◽  
Noise Ratio ◽  
Heel Effect

It was researched on the application of Anoda Heel Effect (AHE) with a step wedge on the effect of Signal To Noise Ratio (SNR) on Computed Radiography (CR) has been carried out. This research was conducted on a 21 step wedge with two treatments, namely the application of AHE and without the application of AHE. This measurement is repeated three times on radiographs to obtain a total image of six images (without the application of AHE as many as three images and with the application of AHE as many as three images). The results of taking radiographs using AHE and without AHE were measured using the RadiAnt Dicom Viewer program. The SNR value on the step wedge image without the AHE application has an average of 26.89. The SNR value on the step wedge image using AHE is 60.54. The results of the correlation test (Pearson correlation test) on the SNR showed that there was a significant and very strong effect of the application of AHE on the step wedge on the SNR in CR (p-value <0.001 and the R-value ranging from 0.600 to 0.799).

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.

SU-EE-A2-05: Accuracy in the Determination of Microcalcification Thickness in Digital Mammography

2005 ◽  
Vol 32 (6Part2) ◽  
pp. 1898-1898
Author(s):  
M-E Brandan ◽  
V Grabski
Keyword(s):  
Digital Mammography

MO-E-I-609-06: Squared Contrast-Noise Ratio Per Dose and Rh-Filter Thickness for Digital Mammography

2005 ◽  
Vol 32 (6Part14) ◽  
pp. 2065-2065
Author(s):  
T Nishino ◽  
X Wu ◽  
R Johnson
Keyword(s):  
Digital Mammography ◽  
Noise Ratio ◽  
Filter Thickness

Threshold pixel size for shape determination of microcalcifications in digital mammography: a pilot study

2005 ◽  
Vol 114 (1-3) ◽  
pp. 415-423 ◽  
Author(s):  
M. Ruschin ◽  
B. Hemdal ◽  
I. Andersson ◽  
S. Börjesson ◽  
M. Håkansson ◽  
...  
Keyword(s):  
Pilot Study ◽  
Digital Mammography ◽  
Pixel Size ◽  
Shape Determination

DETERMINATION OF SIGNAL AND NOISE STATISTICS USING CORRELATION THEORY

Geophysics ◽  
1970 ◽  
Vol 35 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Bibhu P. Dash ◽  
K. Ahmed Obaidullah
Keyword(s):  
Signal To Noise Ratio ◽  
Random Series ◽  
Signal To Noise ◽  
Time Duration ◽  
Optimum Time ◽  
Seismic Wavelet ◽  
Correlation Theory ◽  
Noise Ratio ◽  
Noise Statistics

A seismic trace may be represented as the sum of a signal and noise series. Each of the series may further be represented by convolution of a finite wavelet and a random series. With this representation, and provided that the signal and noise are uncorrelated, it is possible, in theory, to extract signal and noise statistics from two adjacent traces of a reflection seismogram. Some experiments are shown on model seismic traces, and it is shown that within the time‐duration of the seismic wavelet, the estimates of signal and noise statistics are reasonable for low signal‐to‐noise ratio. There remains, however, the problem of determining the optimum time lengths of the estimates.

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