Classification images for localization performance in ramp‐spectrum noise.
Saved in:
| Title: | Classification images for localization performance in ramp‐spectrum noise. |
|---|---|
| Authors: | Abbey, Craig K.1 ckabbey@ucsb.edu, Samuelson, Frank W.2, Zeng, Rongping2, Boone, John M.3, Eckstein, Miguel P.1, Myers, Kyle2 |
| Source: | Medical Physics. May2018, Vol. 45 Issue 5, p1970-1984. 15p. |
| Subjects: | Computed tomography, Apodization, Transfer functions, Psychophysics, Digital filters (Mathematics), Bandwidths |
| Abstract: | Purpose: This study investigates forced localization of targets in simulated images with statistical properties similar to trans‐axial sections of x‐ray computed tomography (CT) volumes. A total of 24 imaging conditions are considered, comprising two target sizes, three levels of background variability, and four levels of frequency apodization. The goal of the study is to better understand how human observers perform forced‐localization tasks in images with CT‐like statistical properties. Methods: The transfer properties of CT systems are modeled by a shift‐invariant transfer function in addition to apodization filters that modulate high spatial frequencies. The images contain noise that is the combination of a ramp‐spectrum component, simulating the effect of acquisition noise in CT, and a power‐law component, simulating the effect of normal anatomy in the background, which are modulated by the apodization filter as well. Observer performance is characterized using two psychophysical techniques: efficiency analysis and classification image analysis. Observer efficiency quantifies how much diagnostic information is being used by observers to perform a task, and classification images show how that information is being accessed in the form of a perceptual filter. Results: Psychophysical studies from five subjects form the basis of the results. Observer efficiency ranges from 29% to 77% across the different conditions. The lowest efficiency is observed in conditions with uniform backgrounds, where significant effects of apodization are found. The classification images, estimated using smoothing windows, suggest that human observers use center‐surround filters to perform the task, and these are subjected to a number of subsequent analyses. When implemented as a scanning linear filter, the classification images appear to capture most of the observer variability in efficiency ( |
| Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| FullText | Links: – Type: pdflink Text: Availability: 1 |
|---|---|
| Header | DbId: egs DbLabel: Engineering Source An: 129573871 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: Classification images for localization performance in ramp‐spectrum noise. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Abbey%2C+Craig+K%2E%22">Abbey, Craig K.</searchLink><relatesTo>1</relatesTo><i> ckabbey@ucsb.edu</i><br /><searchLink fieldCode="AR" term="%22Samuelson%2C+Frank+W%2E%22">Samuelson, Frank W.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Zeng%2C+Rongping%22">Zeng, Rongping</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Boone%2C+John+M%2E%22">Boone, John M.</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Eckstein%2C+Miguel+P%2E%22">Eckstein, Miguel P.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Myers%2C+Kyle%22">Myers, Kyle</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Medical+Physics%22">Medical Physics</searchLink>. May2018, Vol. 45 Issue 5, p1970-1984. 15p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Computed+tomography%22">Computed tomography</searchLink><br /><searchLink fieldCode="DE" term="%22Apodization%22">Apodization</searchLink><br /><searchLink fieldCode="DE" term="%22Transfer+functions%22">Transfer functions</searchLink><br /><searchLink fieldCode="DE" term="%22Psychophysics%22">Psychophysics</searchLink><br /><searchLink fieldCode="DE" term="%22Digital+filters+%28Mathematics%29%22">Digital filters (Mathematics)</searchLink><br /><searchLink fieldCode="DE" term="%22Bandwidths%22">Bandwidths</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Purpose: This study investigates forced localization of targets in simulated images with statistical properties similar to trans‐axial sections of x‐ray computed tomography (CT) volumes. A total of 24 imaging conditions are considered, comprising two target sizes, three levels of background variability, and four levels of frequency apodization. The goal of the study is to better understand how human observers perform forced‐localization tasks in images with CT‐like statistical properties. Methods: The transfer properties of CT systems are modeled by a shift‐invariant transfer function in addition to apodization filters that modulate high spatial frequencies. The images contain noise that is the combination of a ramp‐spectrum component, simulating the effect of acquisition noise in CT, and a power‐law component, simulating the effect of normal anatomy in the background, which are modulated by the apodization filter as well. Observer performance is characterized using two psychophysical techniques: efficiency analysis and classification image analysis. Observer efficiency quantifies how much diagnostic information is being used by observers to perform a task, and classification images show how that information is being accessed in the form of a perceptual filter. Results: Psychophysical studies from five subjects form the basis of the results. Observer efficiency ranges from 29% to 77% across the different conditions. The lowest efficiency is observed in conditions with uniform backgrounds, where significant effects of apodization are found. The classification images, estimated using smoothing windows, suggest that human observers use center‐surround filters to perform the task, and these are subjected to a number of subsequent analyses. When implemented as a scanning linear filter, the classification images appear to capture most of the observer variability in efficiency (<italic>r</italic>2 = 0.86). The frequency spectra of the classification images show that frequency weights generally appear bandpass in nature, with peak frequency and bandwidth that vary with statistical properties of the images. Conclusions: In these experiments, the classification images appear to capture important features of human‐observer performance. Frequency apodization only appears to have a significant effect on performance in the absence of anatomical variability, where the observers appear to underweight low spatial frequencies that have relatively little noise. Frequency weights derived from the classification images generally have a bandpass structure, with adaptation to different conditions seen in the peak frequency and bandwidth. The classification image spectra show relatively modest changes in response to different levels of apodization, with some evidence that observers are attempting to rebalance the apodized spectrum presented to them. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=129573871 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/mp.12857 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 15 StartPage: 1970 Subjects: – SubjectFull: Computed tomography Type: general – SubjectFull: Apodization Type: general – SubjectFull: Transfer functions Type: general – SubjectFull: Psychophysics Type: general – SubjectFull: Digital filters (Mathematics) Type: general – SubjectFull: Bandwidths Type: general Titles: – TitleFull: Classification images for localization performance in ramp‐spectrum noise. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Abbey, Craig K. – PersonEntity: Name: NameFull: Samuelson, Frank W. – PersonEntity: Name: NameFull: Zeng, Rongping – PersonEntity: Name: NameFull: Boone, John M. – PersonEntity: Name: NameFull: Eckstein, Miguel P. – PersonEntity: Name: NameFull: Myers, Kyle IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 05 Text: May2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 00942405 Numbering: – Type: volume Value: 45 – Type: issue Value: 5 Titles: – TitleFull: Medical Physics Type: main |
| ResultId | 1 |
