NEQ and task in dual-energy imaging: From cascaded systems analysis to human observer performance

Samuel Richard, Jeff Siewerdsen, Daniel J. Tward

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The relationship between theoretical descriptions of imaging performance (Fourier-based cascaded systems analysis) and the performance of real human observers was investigated for various detection and discrimination tasks. Dual-energy (DE) imaging provided a useful basis for investigating this relationship, because it presents a host of acquisition and processing parameters that can significantly affect signal and noise transfer characteristics and, correspondingly, human observer performance. The detectability index was computed theoretically using: 1) cascaded systems analysis of the modulation transfer function (MTF), and noise-power spectrum (NPS) for DE imaging; 2) a Fourier description of imaging task; and 3.) integration of MTF, NPS, and task function according to various observer models, including Fisher-Hotelling and non-prewhitening with and without an eye filter and internal noise. Three idealized tasks were considered: sphere detection, shape discrimination (sphere vs. disk), and texture discrimination (uniform vs. textured disk). Using images of phantoms acquired on a prototype DE imaging system, human observer performance was assessed in multiple-alternative forced choice (MAFC) tests, giving an estimate of area under the ROC curve (A Z). The degree to which the theoretical detectability index correlated with human observer performance was investigated, and results agreed well over a broad range of imaging conditions, depending on the choice of observer model. Results demonstrated that optimal DE image acquisition and decomposition parameters depend significantly on the imaging task. These studies provide important initial validation that the detectability index derived theoretically by Fourier-based cascaded systems analysis correlates well with actual human observer performance and represents a meaningful metric for system optimization.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume6913
DOIs
StatePublished - 2008
Externally publishedYes
EventMedical Imaging 2008 - Physics of Medical Imaging - San Diego, CA, United States
Duration: Feb 18 2008Feb 21 2008

Other

OtherMedical Imaging 2008 - Physics of Medical Imaging
CountryUnited States
CitySan Diego, CA
Period2/18/082/21/08

Fingerprint

Systems analysis
Imaging techniques
Optical transfer function
Power spectrum
Image acquisition
Imaging systems
Textures
Decomposition
Processing

Keywords

  • Detectability index
  • Dual-energy imaging
  • Flat-panel detector
  • MAFC
  • MTF
  • NEQ
  • NPS
  • Observer performance

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Richard, S., Siewerdsen, J., & Tward, D. J. (2008). NEQ and task in dual-energy imaging: From cascaded systems analysis to human observer performance. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 6913). [691311] https://doi.org/10.1117/12.772772

NEQ and task in dual-energy imaging : From cascaded systems analysis to human observer performance. / Richard, Samuel; Siewerdsen, Jeff; Tward, Daniel J.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6913 2008. 691311.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Richard, S, Siewerdsen, J & Tward, DJ 2008, NEQ and task in dual-energy imaging: From cascaded systems analysis to human observer performance. in Progress in Biomedical Optics and Imaging - Proceedings of SPIE. vol. 6913, 691311, Medical Imaging 2008 - Physics of Medical Imaging, San Diego, CA, United States, 2/18/08. https://doi.org/10.1117/12.772772
Richard S, Siewerdsen J, Tward DJ. NEQ and task in dual-energy imaging: From cascaded systems analysis to human observer performance. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6913. 2008. 691311 https://doi.org/10.1117/12.772772
Richard, Samuel ; Siewerdsen, Jeff ; Tward, Daniel J. / NEQ and task in dual-energy imaging : From cascaded systems analysis to human observer performance. Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6913 2008.
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