Observer performance with varying radiation dose and reconstruction methods for detection of hepatic metastases

Joel Garland Fletcher, Jeff L. Fidler, Sudhakar K Venkatesh, David M Hough, Naoki M Takahashi, Lifeng Yu, Matthew Johnson, Shuai Leng, David R. Holmes III, Rickey E. Carter, Cynthia H McCollough

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Purpose: To estimate the ability of lower dose levels and iterative reconstruction (IR) to display hepatic metastases that can be detected by radiologists. Materials and Methods: Projection data from 83 contrast agent-enhanced CT examinations were collected. Metastases were defined by histopathologic analysis or progression and regression. Lower radiation dose configurations were reconstructed at five dose levels with filtered back projection (FBP) and IR (automatic exposure control settings: 80, 100, 120, 160, and 200 quality reference mAs [QRM]). Three abdominal radiologists circumscribed metastases, indicating confidence (confidence range, 0-100) and image quality. Noninferiority was assessed by using jackknife alternative free-response receiver operating characteristic (JAFROC) analysis (noninferiority limit, 20.10) and reader agreement rules, which required identification of metastases identified at routine dose, and no nonlesion localizations in patients negative for metastases, in 71 or more patient CT examinations (of 83), for each configuration. Results: There were 123 hepatic metastases (mean size, 1.4 cm; median volume CT dose index and size-specific dose estimate, 11.0 and 13.4 mGy, respectively). By using JAFROC figure of merit, 100 QRM FBP did not meet noninferiority criteria and had estimated performance difference from routine dose of 2 0.08 (95% confidence interval: 20.11, 20.04). Preset reader agreement rules were not met for 100 QRM IR or 80 QRM IR, but were met for doses 120 QRM or higher (ie, size-specific dose estimate ≥ 8.0 mGy). IR improved image quality (P <.05) but not reader performance. Other than 160 QRM IR, lower dose levels were associated with reduced confidence in metastasis detection (P <.001). Conclusion: For detection of hepatic metastases by using contrast-enhanced CT, dose levels that corresponded to 120 quality reference mAs (size-specific dose estimate, 8.0 mGy) and higher performed similarly to 200 quality reference mAs with filtered back projection.

Original languageEnglish (US)
Pages (from-to)455-464
Number of pages10
JournalRadiology
Volume289
Issue number2
DOIs
StatePublished - Nov 1 2018

Fingerprint

Radiation
Neoplasm Metastasis
Liver
ROC Curve
Cone-Beam Computed Tomography
Computer-Assisted Image Processing
Contrast Media
Confidence Intervals
Radiologists

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Observer performance with varying radiation dose and reconstruction methods for detection of hepatic metastases. / Fletcher, Joel Garland; Fidler, Jeff L.; Venkatesh, Sudhakar K; Hough, David M; Takahashi, Naoki M; Yu, Lifeng; Johnson, Matthew; Leng, Shuai; Holmes III, David R.; Carter, Rickey E.; McCollough, Cynthia H.

In: Radiology, Vol. 289, No. 2, 01.11.2018, p. 455-464.

Research output: Contribution to journalArticle

@article{8f5ebab60ad849ad8068191d81be7b60,
title = "Observer performance with varying radiation dose and reconstruction methods for detection of hepatic metastases",
abstract = "Purpose: To estimate the ability of lower dose levels and iterative reconstruction (IR) to display hepatic metastases that can be detected by radiologists. Materials and Methods: Projection data from 83 contrast agent-enhanced CT examinations were collected. Metastases were defined by histopathologic analysis or progression and regression. Lower radiation dose configurations were reconstructed at five dose levels with filtered back projection (FBP) and IR (automatic exposure control settings: 80, 100, 120, 160, and 200 quality reference mAs [QRM]). Three abdominal radiologists circumscribed metastases, indicating confidence (confidence range, 0-100) and image quality. Noninferiority was assessed by using jackknife alternative free-response receiver operating characteristic (JAFROC) analysis (noninferiority limit, 20.10) and reader agreement rules, which required identification of metastases identified at routine dose, and no nonlesion localizations in patients negative for metastases, in 71 or more patient CT examinations (of 83), for each configuration. Results: There were 123 hepatic metastases (mean size, 1.4 cm; median volume CT dose index and size-specific dose estimate, 11.0 and 13.4 mGy, respectively). By using JAFROC figure of merit, 100 QRM FBP did not meet noninferiority criteria and had estimated performance difference from routine dose of 2 0.08 (95{\%} confidence interval: 20.11, 20.04). Preset reader agreement rules were not met for 100 QRM IR or 80 QRM IR, but were met for doses 120 QRM or higher (ie, size-specific dose estimate ≥ 8.0 mGy). IR improved image quality (P <.05) but not reader performance. Other than 160 QRM IR, lower dose levels were associated with reduced confidence in metastasis detection (P <.001). Conclusion: For detection of hepatic metastases by using contrast-enhanced CT, dose levels that corresponded to 120 quality reference mAs (size-specific dose estimate, 8.0 mGy) and higher performed similarly to 200 quality reference mAs with filtered back projection.",
author = "Fletcher, {Joel Garland} and Fidler, {Jeff L.} and Venkatesh, {Sudhakar K} and Hough, {David M} and Takahashi, {Naoki M} and Lifeng Yu and Matthew Johnson and Shuai Leng and {Holmes III}, {David R.} and Carter, {Rickey E.} and McCollough, {Cynthia H}",
year = "2018",
month = "11",
day = "1",
doi = "10.1148/radiol.2018180125",
language = "English (US)",
volume = "289",
pages = "455--464",
journal = "Radiology",
issn = "0033-8419",
publisher = "Radiological Society of North America Inc.",
number = "2",

}

TY - JOUR

T1 - Observer performance with varying radiation dose and reconstruction methods for detection of hepatic metastases

AU - Fletcher, Joel Garland

AU - Fidler, Jeff L.

AU - Venkatesh, Sudhakar K

AU - Hough, David M

AU - Takahashi, Naoki M

AU - Yu, Lifeng

AU - Johnson, Matthew

AU - Leng, Shuai

AU - Holmes III, David R.

AU - Carter, Rickey E.

AU - McCollough, Cynthia H

PY - 2018/11/1

Y1 - 2018/11/1

N2 - Purpose: To estimate the ability of lower dose levels and iterative reconstruction (IR) to display hepatic metastases that can be detected by radiologists. Materials and Methods: Projection data from 83 contrast agent-enhanced CT examinations were collected. Metastases were defined by histopathologic analysis or progression and regression. Lower radiation dose configurations were reconstructed at five dose levels with filtered back projection (FBP) and IR (automatic exposure control settings: 80, 100, 120, 160, and 200 quality reference mAs [QRM]). Three abdominal radiologists circumscribed metastases, indicating confidence (confidence range, 0-100) and image quality. Noninferiority was assessed by using jackknife alternative free-response receiver operating characteristic (JAFROC) analysis (noninferiority limit, 20.10) and reader agreement rules, which required identification of metastases identified at routine dose, and no nonlesion localizations in patients negative for metastases, in 71 or more patient CT examinations (of 83), for each configuration. Results: There were 123 hepatic metastases (mean size, 1.4 cm; median volume CT dose index and size-specific dose estimate, 11.0 and 13.4 mGy, respectively). By using JAFROC figure of merit, 100 QRM FBP did not meet noninferiority criteria and had estimated performance difference from routine dose of 2 0.08 (95% confidence interval: 20.11, 20.04). Preset reader agreement rules were not met for 100 QRM IR or 80 QRM IR, but were met for doses 120 QRM or higher (ie, size-specific dose estimate ≥ 8.0 mGy). IR improved image quality (P <.05) but not reader performance. Other than 160 QRM IR, lower dose levels were associated with reduced confidence in metastasis detection (P <.001). Conclusion: For detection of hepatic metastases by using contrast-enhanced CT, dose levels that corresponded to 120 quality reference mAs (size-specific dose estimate, 8.0 mGy) and higher performed similarly to 200 quality reference mAs with filtered back projection.

AB - Purpose: To estimate the ability of lower dose levels and iterative reconstruction (IR) to display hepatic metastases that can be detected by radiologists. Materials and Methods: Projection data from 83 contrast agent-enhanced CT examinations were collected. Metastases were defined by histopathologic analysis or progression and regression. Lower radiation dose configurations were reconstructed at five dose levels with filtered back projection (FBP) and IR (automatic exposure control settings: 80, 100, 120, 160, and 200 quality reference mAs [QRM]). Three abdominal radiologists circumscribed metastases, indicating confidence (confidence range, 0-100) and image quality. Noninferiority was assessed by using jackknife alternative free-response receiver operating characteristic (JAFROC) analysis (noninferiority limit, 20.10) and reader agreement rules, which required identification of metastases identified at routine dose, and no nonlesion localizations in patients negative for metastases, in 71 or more patient CT examinations (of 83), for each configuration. Results: There were 123 hepatic metastases (mean size, 1.4 cm; median volume CT dose index and size-specific dose estimate, 11.0 and 13.4 mGy, respectively). By using JAFROC figure of merit, 100 QRM FBP did not meet noninferiority criteria and had estimated performance difference from routine dose of 2 0.08 (95% confidence interval: 20.11, 20.04). Preset reader agreement rules were not met for 100 QRM IR or 80 QRM IR, but were met for doses 120 QRM or higher (ie, size-specific dose estimate ≥ 8.0 mGy). IR improved image quality (P <.05) but not reader performance. Other than 160 QRM IR, lower dose levels were associated with reduced confidence in metastasis detection (P <.001). Conclusion: For detection of hepatic metastases by using contrast-enhanced CT, dose levels that corresponded to 120 quality reference mAs (size-specific dose estimate, 8.0 mGy) and higher performed similarly to 200 quality reference mAs with filtered back projection.

UR - http://www.scopus.com/inward/record.url?scp=85055075954&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85055075954&partnerID=8YFLogxK

U2 - 10.1148/radiol.2018180125

DO - 10.1148/radiol.2018180125

M3 - Article

C2 - 30204077

AN - SCOPUS:85055075954

VL - 289

SP - 455

EP - 464

JO - Radiology

JF - Radiology

SN - 0033-8419

IS - 2

ER -