Impact of number of repeated scans on model observer performance for a low-contrast detection task in computed tomography

Chi Ma, Lifeng Yu, Baiyu Chen, Christopher Favazza, Shuai Leng, Cynthia H McCollough

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Channelized Hotelling observer (CHO) models have been shown to correlate well with human observers for several phantom-based detection/classification tasks in clinical computed tomography (CT). A large number of repeated scans were used to achieve an accurate estimate of the model's template. The purpose of this study is to investigate how the experimental and CHO model parameters affect the minimum required number of repeated scans. A phantom containing 21 low-contrast objects was scanned on a 128-slice CT scanner at three dose levels. Each scan was repeated 100 times. For each experimental configuration, the low-contrast detectability, quantified as the area under receiver operating characteristic curve, Az, was calculated using a previously validated CHO with randomly selected subsets of scans, ranging from 10 to 100. Using Az from the 100 scans as the reference, the accuracy from a smaller number of scans was determined. Our results demonstrated that the minimum number of repeated scans increased when the radiation dose level decreased, object size and contrast level decreased, and the number of channels increased. As a general trend, it increased as the low-contrast detectability decreased. This study provides a basis for the experimental design of task-based image quality assessment in clinical CT using CHO.

Original languageEnglish (US)
Article number023504
JournalJournal of Medical Imaging
Volume3
Issue number2
DOIs
StatePublished - Apr 1 2016

Fingerprint

Tomography
X-Ray Computed Tomography Scanners
ROC Curve
Research Design
Radiation

Keywords

  • channelized Hotelling observer
  • computed tomography
  • model observer
  • radiation dose reduction
  • task-based image quality assessment

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Impact of number of repeated scans on model observer performance for a low-contrast detection task in computed tomography. / Ma, Chi; Yu, Lifeng; Chen, Baiyu; Favazza, Christopher; Leng, Shuai; McCollough, Cynthia H.

In: Journal of Medical Imaging, Vol. 3, No. 2, 023504, 01.04.2016.

Research output: Contribution to journalArticle

@article{0642e06d4030438eac44e3cf537cd9c9,
title = "Impact of number of repeated scans on model observer performance for a low-contrast detection task in computed tomography",
abstract = "Channelized Hotelling observer (CHO) models have been shown to correlate well with human observers for several phantom-based detection/classification tasks in clinical computed tomography (CT). A large number of repeated scans were used to achieve an accurate estimate of the model's template. The purpose of this study is to investigate how the experimental and CHO model parameters affect the minimum required number of repeated scans. A phantom containing 21 low-contrast objects was scanned on a 128-slice CT scanner at three dose levels. Each scan was repeated 100 times. For each experimental configuration, the low-contrast detectability, quantified as the area under receiver operating characteristic curve, Az, was calculated using a previously validated CHO with randomly selected subsets of scans, ranging from 10 to 100. Using Az from the 100 scans as the reference, the accuracy from a smaller number of scans was determined. Our results demonstrated that the minimum number of repeated scans increased when the radiation dose level decreased, object size and contrast level decreased, and the number of channels increased. As a general trend, it increased as the low-contrast detectability decreased. This study provides a basis for the experimental design of task-based image quality assessment in clinical CT using CHO.",
keywords = "channelized Hotelling observer, computed tomography, model observer, radiation dose reduction, task-based image quality assessment",
author = "Chi Ma and Lifeng Yu and Baiyu Chen and Christopher Favazza and Shuai Leng and McCollough, {Cynthia H}",
year = "2016",
month = "4",
day = "1",
doi = "10.1117/1.JMI.3.2.023504",
language = "English (US)",
volume = "3",
journal = "Journal of Medical Imaging",
issn = "0720-048X",
publisher = "Elsevier Ireland Ltd",
number = "2",

}

TY - JOUR

T1 - Impact of number of repeated scans on model observer performance for a low-contrast detection task in computed tomography

AU - Ma, Chi

AU - Yu, Lifeng

AU - Chen, Baiyu

AU - Favazza, Christopher

AU - Leng, Shuai

AU - McCollough, Cynthia H

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Channelized Hotelling observer (CHO) models have been shown to correlate well with human observers for several phantom-based detection/classification tasks in clinical computed tomography (CT). A large number of repeated scans were used to achieve an accurate estimate of the model's template. The purpose of this study is to investigate how the experimental and CHO model parameters affect the minimum required number of repeated scans. A phantom containing 21 low-contrast objects was scanned on a 128-slice CT scanner at three dose levels. Each scan was repeated 100 times. For each experimental configuration, the low-contrast detectability, quantified as the area under receiver operating characteristic curve, Az, was calculated using a previously validated CHO with randomly selected subsets of scans, ranging from 10 to 100. Using Az from the 100 scans as the reference, the accuracy from a smaller number of scans was determined. Our results demonstrated that the minimum number of repeated scans increased when the radiation dose level decreased, object size and contrast level decreased, and the number of channels increased. As a general trend, it increased as the low-contrast detectability decreased. This study provides a basis for the experimental design of task-based image quality assessment in clinical CT using CHO.

AB - Channelized Hotelling observer (CHO) models have been shown to correlate well with human observers for several phantom-based detection/classification tasks in clinical computed tomography (CT). A large number of repeated scans were used to achieve an accurate estimate of the model's template. The purpose of this study is to investigate how the experimental and CHO model parameters affect the minimum required number of repeated scans. A phantom containing 21 low-contrast objects was scanned on a 128-slice CT scanner at three dose levels. Each scan was repeated 100 times. For each experimental configuration, the low-contrast detectability, quantified as the area under receiver operating characteristic curve, Az, was calculated using a previously validated CHO with randomly selected subsets of scans, ranging from 10 to 100. Using Az from the 100 scans as the reference, the accuracy from a smaller number of scans was determined. Our results demonstrated that the minimum number of repeated scans increased when the radiation dose level decreased, object size and contrast level decreased, and the number of channels increased. As a general trend, it increased as the low-contrast detectability decreased. This study provides a basis for the experimental design of task-based image quality assessment in clinical CT using CHO.

KW - channelized Hotelling observer

KW - computed tomography

KW - model observer

KW - radiation dose reduction

KW - task-based image quality assessment

UR - http://www.scopus.com/inward/record.url?scp=84973591034&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84973591034&partnerID=8YFLogxK

U2 - 10.1117/1.JMI.3.2.023504

DO - 10.1117/1.JMI.3.2.023504

M3 - Article

AN - SCOPUS:84973591034

VL - 3

JO - Journal of Medical Imaging

JF - Journal of Medical Imaging

SN - 0720-048X

IS - 2

M1 - 023504

ER -