A controlled statistical study to assess measurement variability as a function of test object position and configuration for automated surveillance in a multicenter longitudinal COPD study (SPIROMICS)

Junfeng Guo; Chao Wang; Kung-Sik Chan; Dakai Jin; Punam K Saha; Jered P Sieren; R G Barr; MeiLan K Han; Ella Kazerooni; Christopher B Cooper; David Couper; John D Newell Jr; Eric A Hoffman

doi:10.1118/1.4947303

Back

A controlled statistical study to assess measurement variability as a function of test object position and configuration for automated surveillance in a multicenter longitudinal COPD study (SPIROMICS)

Journal article

Open access

Peer reviewed

A controlled statistical study to assess measurement variability as a function of test object position and configuration for automated surveillance in a multicenter longitudinal COPD study (SPIROMICS)

Junfeng Guo, Chao Wang, Kung-Sik Chan, Dakai Jin, Punam K Saha, Jered P Sieren, R G Barr, MeiLan K Han, Ella Kazerooni, Christopher B Cooper, …

Medical physics (Lancaster), Vol.43(5), pp.2598-2610

05/2016

DOI: 10.1118/1.4947303

PMCID: PMC4851622

PMID: 27147369

Files and links (1)

url

https://doi.org/10.1118/1.4947303View

Published (Version of record) Open Access

Abstract

A test object (phantom) is an important tool to evaluate comparability and stability of CT scanners used in multicenter and longitudinal studies. However, there are many sources of error that can interfere with the test object-derived quantitative measurements. Here the authors investigated three major possible sources of operator error in the use of a test object employed to assess pulmonary density-related as well as airway-related metrics. Two kinds of experiments were carried out to assess measurement variability caused by imperfect scanning status. The first one consisted of three experiments. A COPDGene test object was scanned using a dual source multidetector computed tomographic scanner (Siemens Somatom Flash) with the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) inspiration protocol (120 kV, 110 mAs, pitch = 1, slice thickness = 0.75 mm, slice spacing = 0.5 mm) to evaluate the effects of tilt angle, water bottle offset, and air bubble size. After analysis of these results, a guideline was reached in order to achieve more reliable results for this test object. Next the authors applied the above findings to 2272 test object scans collected over 4 years as part of the SPIROMICS study. The authors compared changes of the data consistency before and after excluding the scans that failed to pass the guideline. This study established the following limits for the test object: tilt index ≤0.3, water bottle offset limits of [-6.6 mm, 7.4 mm], and no air bubble within the water bottle, where tilt index is a measure incorporating two tilt angles around x- and y-axis. With 95% confidence, the density measurement variation for all five interested materials in the test object (acrylic, water, lung, inside air, and outside air) resulting from all three error sources can be limited to ±0.9 HU (summed in quadrature), when all the requirements are satisfied. The authors applied these criteria to 2272 SPIROMICS scans and demonstrated a significant reduction in measurement variation associated with the test object. Three operator errors were identified which significantly affected the usability of the acquired scan images of the test object used for monitoring scanner stability in a multicenter study. The authors' results demonstrated that at the time of test object scan receipt at a radiology core laboratory, quality control procedures should include an assessment of tilt index, water bottle offset, and air bubble size within the water bottle. Application of this methodology to 2272 SPIROMICS scans indicated that their findings were not limited to the scanner make and model used for the initial test but was generalizable to both Siemens and GE scanners which comprise the scanner types used within the SPIROMICS study.

Water

Multidetector Computed Tomography - instrumentation

Data Interpretation, Statistical

Multidetector Computed Tomography - methods

Air

Phantoms, Imaging

Longitudinal Studies

Pattern Recognition, Automated - methods

Models, Anatomic

Quality Control

Details

Title: Subtitle: A controlled statistical study to assess measurement variability as a function of test object position and configuration for automated surveillance in a multicenter longitudinal COPD study (SPIROMICS)
Creators: Junfeng Guo - Departments of Radiology and Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242
Chao Wang - Department of Statistics and Actuarial Science, University of Iowa, Iowa City, Iowa 52242
Kung-Sik Chan - Department of Statistics and Actuarial Science, University of Iowa, Iowa City, Iowa 52242
Dakai Jin - Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242
Punam K Saha - Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242
Jered P Sieren - Department of Radiology, University of Iowa, Iowa City, Iowa 52242
R G Barr - Departments of Medicine and Epidemiology, Columbia University Medical Center, New York, New York 10032
MeiLan K Han - Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, Michigan 48109
Ella Kazerooni - Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109
Christopher B Cooper - Department of Medicine, University of California, Los Angeles, California 90095
David Couper - Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina 27599
John D Newell Jr - Departments of Radiology and Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242
Eric A Hoffman - Departments of Radiology, Medicine and Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242
Resource Type: Journal article
Publication Details: Medical physics (Lancaster), Vol.43(5), pp.2598-2610
DOI: 10.1118/1.4947303
PMID: 27147369
PMCID: PMC4851622
NLM abbreviation: Med Phys
ISSN: 0094-2405
eISSN: 2473-4209
Publisher: United States
Grant note: HHSN268200900017C / NHLBI NIH HHS P30 ES005605 / NIEHS NIH HHS HHSN268200900019C / NHLBI NIH HHS HHSN268200900020C / NHLBI NIH HHS HHSN268200900015C / NHLBI NIH HHS HHSN268200900013C / NHLBI NIH HHS R01 HL112986 / NHLBI NIH HHS P30 CA086862 / NCI NIH HHS HHSN268200900016C / NHLBI NIH HHS HHSN268200900018C / NHLBI NIH HHS HHSN268200900014C / NHLBI NIH HHS S10 OD018526 / NIH HHS P30 DK054759 / NIDDK NIH HHS
Language: English
Date published: 05/2016
Academic Unit: Statistics and Actuarial Science; Roy J. Carver Department of Biomedical Engineering; Radiology; Electrical and Computer Engineering; Internal Medicine
Record Identifier: 9984051519202771

Metrics

38 Record Views

8 Times Cited - Web of Science