Estimation of the noisy component of anatomical backgrounds.

Details

Serval ID
serval:BIB_C27EC952DB7B
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Estimation of the noisy component of anatomical backgrounds.
Journal
Medical physics
Author(s)
Bochud F.O., Valley J.F., Verdun F.R., Hessler C., Schnyder P.
ISSN
0094-2405
Publication state
Published
Issued date
1999
Peer-reviewed
Oui
Volume
26
Number
7
Pages
1365-70
Language
english
Notes
Publication types: Journal Article - Publication Status: ppublish
Abstract
The knowledge of the relationship that links radiation dose and image quality is a prerequisite to any optimization of medical diagnostic radiology. Image quality depends, on the one hand, on the physical parameters such as contrast, resolution, and noise, and on the other hand, on characteristics of the observer that assesses the image. While the role of contrast and resolution is precisely defined and recognized, the influence of image noise is not yet fully understood. Its measurement is often based on imaging uniform test objects, even though real images contain anatomical backgrounds whose statistical nature is much different from test objects used to assess system noise. The goal of this study was to demonstrate the importance of variations in background anatomy by quantifying its effect on a series of detection tasks. Several types of mammographic backgrounds and signals were examined by psychophysical experiments in a two-alternative forced-choice detection task. According to hypotheses concerning the strategy used by the human observers, their signal to noise ratio was determined. This variable was also computed for a mathematical model based on the statistical decision theory. By comparing theoretical model and experimental results, the way that anatomical structure is perceived has been analyzed. Experiments showed that the observer's behavior was highly dependent upon both system noise and the anatomical background. The anatomy partly acts as a signal recognizable as such and partly as a pure noise that disturbs the detection process. This dual nature of the anatomy is quantified. It is shown that its effect varies according to its amplitude and the profile of the object being detected. The importance of the noisy part of the anatomy is, in some situations, much greater than the system noise. Hence, reducing the system noise by increasing the dose will not improve task performance. This observation indicates that the tradeoff between dose and image quality might be optimized by accepting a higher system noise. This could lead to a better resolution, more contrast, or less dose.
Keywords
Biophysics, Breast, Female, Humans, Mammography, Models, Biological, Observer Variation, Radiation Dosage, Reproducibility of Results
Pubmed
Web of science
Create date
25/04/2008 17:11
Last modification date
20/08/2019 15:37
Usage data