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 language | English (US) |
|---|---|
| Article number | 023504 |
| Journal | Journal of Medical Imaging |
| Volume | 3 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 1 2016 |
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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 journal › Article
}
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 -