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Motahari A, Barr RG, Han MK, Anderson WH, Barjaktarevic I, Bleecker ER, Comellas AP, Cooper CB, Couper DJ, Hansel NN, Kanner RE, Kazerooni EA, Lynch DA, Martinez FJ, Newell JD, Schroeder JD, Smith BM, Woodruff PG, Hoffman EA. Repeatability of Pulmonary Quantitative Computed Tomography Measurements in Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med 2023; 208:657-665. [PMID: 37490608 PMCID: PMC10515564 DOI: 10.1164/rccm.202209-1698pp] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 07/24/2023] [Indexed: 07/27/2023] Open
Affiliation(s)
| | - R. Graham Barr
- Department of Medicine and
- Department of Epidemiology, Columbia University College of Medicine, New York, New York
| | | | - Wayne H. Anderson
- Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Igor Barjaktarevic
- Division of Pulmonary and Critical Care Medicine, University of California Los Angeles Medical Center, Los Angeles, California
| | | | - Alejandro P. Comellas
- Department of Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Christopher B. Cooper
- Department of Medicine and
- Department of Physiology, University of California Los Angeles, Los Angeles, California
| | - David J. Couper
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Nadia N. Hansel
- Department of Medicine, The Johns Hopkins University, Baltimore, Maryland
| | | | - Ella A. Kazerooni
- Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - David A. Lynch
- Department of Radiology, National Jewish Health, Denver, Colorado
| | | | - John D. Newell
- Department of Radiology and
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | | | - Benjamin M. Smith
- Department of Medicine and
- Department of Epidemiology, Columbia University College of Medicine, New York, New York
- Department of Medicine, McGill University, Montreal, Quebec, Canada; and
| | - Prescott G. Woodruff
- Department of Medicine, University of California San Francisco, San Francisco, California
| | - Eric A. Hoffman
- Department of Radiology and
- Department of Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
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Abadi E, Jadick G, Lynch DA, Segars WP, Samei E. Emphysema Quantifications With CT Scan: Assessing the Effects of Acquisition Protocols and Imaging Parameters Using Virtual Imaging Trials. Chest 2023; 163:1084-1100. [PMID: 36462532 PMCID: PMC10206513 DOI: 10.1016/j.chest.2022.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 11/01/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND CT scan has notable potential to quantify the severity and progression of emphysema in patients. Such quantification should ideally reflect the true attributes and pathologic conditions of subjects, not scanner parameters. To achieve such an objective, the effects of the scanner conditions need to be understood so the influence can be mitigated. RESEARCH QUESTION How do CT scan imaging parameters affect the accuracy of emphysema-based quantifications and biomarkers? STUDY DESIGN AND METHODS Twenty anthropomorphic digital phantoms were developed with diverse anatomic attributes and emphysema abnormalities informed by a real COPD cohort. The phantoms were input to a validated CT scan simulator (DukeSim), modeling a commercial scanner (Siemens Flash). Virtual images were acquired under various clinical conditions of dose levels, tube current modulations (TCM), and reconstruction techniques and kernels. The images were analyzed to evaluate the effects of imaging parameters on the accuracy of density-based quantifications (percent of lung voxels with HU < -950 [LAA-950] and 15th percentile of lung histogram HU [Perc15]) across varied subjects. Paired t tests were performed to explore statistical differences between any two imaging conditions. RESULTS The most accurate imaging condition corresponded to the highest acquired dose (100 mAs) and iterative reconstruction (SAFIRE) with the smooth kernel of I31, where the measurement errors (difference between measurement and ground truth) were 35 ± 3 Hounsfield Units (HU), -4% ± 5%, and 26 ± 10 HU (average ± SD), for the mean lung HU, LAA-950, and Perc15, respectively. Without TCM and at the I31 kernel, increase of dose (20 to 100 mAs) improved the lung mean absolute error (MAE) by 4.2 ± 2.3 HU (average ± SD). TCM did not contribute to a systematic improvement of lung MAE. INTERPRETATION The results highlight that although CT scan quantification is possible, its reliability is impacted by the choice of imaging parameters. The developed virtual imaging trial platform in this study enables comprehensive evaluation of CT scan methods in reliable quantifications, an effort that cannot be readily made with patient images or simplistic physical phantoms.
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Affiliation(s)
- Ehsan Abadi
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University School of Medicine, Durham, NC; Department of Electrical & Computer Engineering, Duke University, Durham, NC; Medical Physics Graduate Program, Duke University, Durham, NC.
| | - Giavanna Jadick
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University School of Medicine, Durham, NC
| | - David A Lynch
- Department of Radiology, National Jewish Health, Denver, CO
| | - W Paul Segars
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University School of Medicine, Durham, NC; Medical Physics Graduate Program, Duke University, Durham, NC; Department of Biomedical Engineering, Duke University, Durham, NC
| | - Ehsan Samei
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University School of Medicine, Durham, NC; Department of Electrical & Computer Engineering, Duke University, Durham, NC; Medical Physics Graduate Program, Duke University, Durham, NC; Department of Biomedical Engineering, Duke University, Durham, NC; Department of Physics, Duke University, Durham, NC
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Bakker JT, Klooster K, Bouwman J, Pelgrim GJ, Vliegenthart R, Slebos DJ. Evaluation of spirometry-gated computed tomography to measure lung volumes in emphysema patients. ERJ Open Res 2021; 8:00492-2021. [PMID: 35083322 PMCID: PMC8784891 DOI: 10.1183/23120541.00492-2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 11/30/2021] [Indexed: 11/05/2022] Open
Abstract
IntroductionIn emphysema patient being evaluated for bronchoscopic lung volume reduction (BLVR), accurate measurement of lung volumes is important. Total lung capacity (TLC) and residual volume (RV) are commonly measured by body plethysmography but can also be derived from chest computed tomography (CT). Spirometry-gated CT scanning potentially improves the agreement of CT and body plethysmography. The aim of this study was to compare lung volumes derived from spirometry-gated CT and “breath-hold-coached” CT to the reference standard: body plethysmography.MethodsIn this single-centre retrospective cohort study, emphysema patients being evaluated for BLVR underwent body plethysmography, inspiration (TLC) and expiration (RV) CT scan with spirometer guidance (“gated group”) or with breath-hold-coaching (“non-gated group”). Quantitative analysis was used to calculate lung volumes from the CT.Results200 patients were included in the study (mean±sd age 62±8 years, forced expiratory flow in 1 s 29.2±8.7%, TLC 7.50±1.46 L, RV 4.54±1.07 L). The mean±sd CT-derived TLC was 280±340 mL lower compared to body plethysmography in the gated group (n=100), and 590±430 mL lower for the non-gated group (n=100) (both p<0.001). The mean±sd CT-derived RV was 300±470 mL higher in the gated group and 700±720 mL higher in the non-gated group (both p<0.001). Pearson correlation factors were 0.947 for TLC gated, 0.917 for TLC non-gated, 0.823 for RV gated, 0.693 for RV non-gated, 0.539 for %RV/TLC gated and 0.204 for %RV/TLC non-gated. The differences between the gated and non-gated CT results for TLC and RV were significant for all measurements (p<0.001).ConclusionIn severe COPD patients with emphysema, CT-derived lung volumes are strongly correlated to body plethysmography lung volumes, and especially for RV, more accurate when using spirometry gating.
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Bakker JT, Klooster K, Vliegenthart R, Slebos DJ. Measuring pulmonary function in COPD using quantitative chest computed tomography analysis. Eur Respir Rev 2021; 30:30/161/210031. [PMID: 34261743 PMCID: PMC9518001 DOI: 10.1183/16000617.0031-2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/08/2021] [Indexed: 12/25/2022] Open
Abstract
COPD is diagnosed and evaluated by pulmonary function testing (PFT). Chest computed tomography (CT) primarily serves a descriptive role for diagnosis and severity evaluation. CT densitometry-based emphysema quantification and lobar fissure integrity assessment are most commonly used, mainly for lung volume reduction purposes and scientific efforts. A shift towards a more quantitative role for CT to assess pulmonary function is a logical next step, since more, currently underutilised, information is present in CT images. For instance, lung volumes such as residual volume and total lung capacity can be extracted from CT; these are strongly correlated to lung volumes measured by PFT. This review assesses the current evidence for use of quantitative CT as a proxy for PFT in COPD and discusses challenges in the movement towards CT as a more quantitative modality in COPD diagnosis and evaluation. To better understand the relevance of the traditional PFT measurements and the role CT might play in the replacement of these parameters, COPD pathology and traditional PFT measurements are discussed. CT may be used as a proxy for lung function in COPD diagnosis and evaluation, particularly for the hyperinflation markershttps://bit.ly/2RrGAZf
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Affiliation(s)
- Jens T Bakker
- Dept of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Karin Klooster
- Dept of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Rozemarijn Vliegenthart
- Dept of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Dirk-Jan Slebos
- Dept of Pulmonary Diseases, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Hatt CR, Oh AS, Obuchowski NA, Charbonnier JP, Lynch DA, Humphries SM. Comparison of CT Lung Density Measurements between Standard Full-Dose and Reduced-Dose Protocols. Radiol Cardiothorac Imaging 2021; 3:e200503. [PMID: 33969308 DOI: 10.1148/ryct.2021200503] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/31/2021] [Accepted: 02/09/2021] [Indexed: 11/11/2022]
Abstract
Purpose To evaluate the reproducibility and predicted clinical outcomes of CT-based quantitative lung density measurements using standard fixed-dose (FD) and reduced-dose (RD) scans. Materials and Methods In this retrospective analysis of prospectively acquired data, 1205 participants (mean age, 65 years ± 9 [standard deviation]; 618 men) enrolled in the COPDGene study who underwent FD and RD CT image acquisition protocols between November 2014 and July 2017 were included. Of these, the RD scans of 640 participants were also reconstructed using iterative reconstruction (IR). Median filtering was applied to the RD scans (RD-MF) to investigate an alternative noise reduction strategy. CT attenuation at the 15th percentile of the lung CT histogram (Perc15) was computed for all image types (FD, RD, RD-MF, and RD-IR). Reproducibility coefficients were calculated to quantify the measurement differences between FD and RD scans. The ability of Perc15 to predict chronic obstructive pulmonary disease (COPD) diagnosis and exacerbation frequency was investigated using receiver operating characteristic analysis. Results The Perc15 reproducibility coefficients with and without volume adjustment were as follows: RD, 29.43 HU ± 0.62 versus 32.81 HU ± 1.70; RD-MF, 7.42 HU ± 0.42 versus 19.40 HU ± 2.65; and RD-IR, 7.10 HU ± 0.52 versus 22.46 HU ± 3.91. Receiver operating characteristic curve analysis indicated that Perc15 on volume-adjusted FD and RD scans were both predictive for COPD diagnosis (area under the receiver operating characteristic curve [AUC]: FD, 0.724 ± 0.045; RD, 0.739 ± 0.045) and for having one or more exacerbation per year (AUCs: FD, 0.593 ± 0.068; RD, 0.589 ± 0.066). Similar trends were observed when volume adjustment was not applied. Conclusion A combination of volume adjustment and noise reduction filtering improved the reproducibility of lung density measurements computed using serial FD and RD CT scans.Supplemental material is available for this article.© RSNA, 2021.
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Affiliation(s)
- Charles R Hatt
- Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.)
| | - Andrea S Oh
- Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.)
| | - Nancy A Obuchowski
- Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.)
| | - Jean-Paul Charbonnier
- Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.)
| | - David A Lynch
- Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.)
| | - Stephen M Humphries
- Imbio LLC, 1015 Glenwood Ave, Minneapolis, MN 55405 (C.R.H.); School of Medicine and Public Health, Division of Radiology, University of Michigan, Ann Arbor, Mich (C.R.H.); Department of Radiology, National Jewish Health, Denver, Colo (A.S.O., D.A.L., S.M.H.); Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio (N.A.O.); and Thirona, Nijmegen, the Netherlands (J.P.C.)
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Kim GHJ, Goldin JG, Hayes W, Oh A, Soule B, Du S. The value of imaging and clinical outcomes in a phase II clinical trial of a lysophosphatidic acid receptor antagonist in idiopathic pulmonary fibrosis. Ther Adv Respir Dis 2021; 15:17534666211004238. [PMID: 33781141 PMCID: PMC8013716 DOI: 10.1177/17534666211004238] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 02/22/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrotic lung disease characterized by worsening dyspnea and lung function and has a median survival of 2-3 years. Forced vital capacity (FVC) is the primary endpoint used most commonly in IPF clinical trials as it is the best surrogate for mortality. This study assessed quantitative scores from high-resolution computed tomography (HRCT) developed by machine learning as a secondary efficacy endpoint in a 26-week phase II study of BMS-986020 - an LPA1 receptor antagonist - in patients with IPF. METHODS HRCT scans from 96% (137/142) of randomized subjects were utilized. Quantitative lung fibrosis (QLF) scores were calculated from the HRCT images. QLF improvement was defined as ⩾2% reduction in QLF score from baseline to week 26. RESULTS In the placebo arm, 5% of patients demonstrated an improvement in QLF score at week 26 compared with 15% and 27% of patients in the BMS-986020 600 mg once daily (QD) and twice daily (BID) arms, respectively [versus placebo: p = 0.08 (600 mg QD); p = 0.0098 (600 mg BID)]. Significant correlations were found between changes in QLF and changes in percent predicted FVC, diffusing capacity for carbon monoxide (DLCO), and shortness of breath at week 26 (ρ = -0.41, ρ = -0.22, and ρ = 0.27, respectively; all p < 0.01). CONCLUSIONS This study demonstrated the utility of quantitative HRCT as an efficacy endpoint for IPF in a double-blind, placebo-controlled clinical trial setting.The reviews of this paper are available via the supplemental material section.
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Affiliation(s)
- Grace Hyun J. Kim
- Department of Radiological Sciences, David-Geffen School of Medicine, and Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, CA, USA
| | - Jonathan G. Goldin
- Department of Radiological Sciences, David-Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | | | - Andrea Oh
- Department of Radiology, National Jewish Health, Denver, CO, USA
| | | | - Shuyan Du
- Bristol Myers Squibb, Princeton, NJ, USA
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Li R, Qi Y, Han M, Geng B, Wang G, Han M. Computed tomography reveals microenvironment changes in premetastatic lung. Eur Radiol 2020; 31:4340-4349. [PMID: 33219849 DOI: 10.1007/s00330-020-07500-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 10/03/2020] [Accepted: 11/11/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Microenvironment changes had occurred in the metastatic organs before the arriving of the metastatic tumor cells. In this study, we evaluated the effectiveness of computed tomography (CT) images in quantifying the microenvironment changes in the premetastatic lung under both laboratory and clinical conditions. METHOD Free-breathing Balb/c mice underwent micro-CT repeatedly after the implantation of 4T1 breast tumor. CT-derived indicators (aerated lung volume, lung tissue volume, total lung volume, mean lung density, and the ratio of aerated lung volume to the total lung volume) were quantified. Hematoxylin-eosin staining was used to display the microenvironment changes in premetastatic lung. Moreover, we examined healthy adult women, adult women with histopathologically confirmed primary breast cancer, and adult women with histopathologically confirmed primary breast cancer and lung metastases in our institution to test whether the indicators derived from lung CT images changed with the growth of breast cancer. RESULTS In 4T1 tumor-bearing mice, lung density is increased before lung masses can be recognized on CT images and is correlated with the severity of inflammation in the lung microenvironment. In primary breast tumor-bearing patients, lung density is also increased before the clinical diagnosis of pulmonary metastasis and is correlated with disease score, which represents tumor progression. CONCLUSIONS CT is a reliable and quantitative tool that yields dynamic information on metastatic processes. Microenvironmental changes had occurred in patients' lung tissue before the clinical diagnosis of pulmonary metastasis. Our research will provide new insight for clinical research on the premetastatic niche. KEY POINTS • CT, which provides dynamic information on metastatic processes, is a reliable and quantitative tool to bridge laboratory and clinical studies of the premetastatic niche. • We confirmed that microenvironmental changes occurred in patients' lung tissue before clinicians could diagnose pulmonary metastasis. • Our results provide evidence for the study of the premetastatic niche by analyzing information obtained from CT images.
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Affiliation(s)
- Ranran Li
- Cancer Therapy and Research Center, Shandong Provincial Hospital affiliated to Shandong University, Shandong University, 324 Jingwuweiqi Road, Jinan, 250021, People's Republic of China
| | - Yana Qi
- Cancer Therapy and Research Center, Shandong Provincial Hospital affiliated to Shandong University, Shandong University, 324 Jingwuweiqi Road, Jinan, 250021, People's Republic of China
| | - Meng Han
- School of Basic Medical Sciences, Shandong First Medical University, Jinan, People's Republic of China
| | - Baocheng Geng
- Cancer Therapy and Research Center, Shandong Provincial Hospital affiliated to Shandong University, Shandong University, 324 Jingwuweiqi Road, Jinan, 250021, People's Republic of China
| | - Guangyu Wang
- Cancer Therapy and Research Center, Shandong Provincial Hospital affiliated to Shandong University, Shandong University, 324 Jingwuweiqi Road, Jinan, 250021, People's Republic of China
| | - Mingyong Han
- Cancer Therapy and Research Center, Shandong Provincial Hospital affiliated to Shandong University, Shandong University, 324 Jingwuweiqi Road, Jinan, 250021, People's Republic of China.
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Chronic Obstructive Pulmonary Disease Quantification Using CT Texture Analysis and Densitometry: Results From the Danish Lung Cancer Screening Trial. AJR Am J Roentgenol 2020; 214:1269-1279. [DOI: 10.2214/ajr.19.22300] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Wang X, Teng P, Ontiveros A, Goldin JG, Brown MS. High throughput image labeling on chest computed tomography by deep learning. J Med Imaging (Bellingham) 2020; 7:024501. [PMID: 32219151 DOI: 10.1117/1.jmi.7.2.024501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 02/26/2020] [Indexed: 11/14/2022] Open
Abstract
When mining image data from PACs or clinical trials or processing large volumes of data without curation, the relevant scans must be identified among irrelevant or redundant data. Only images acquired with appropriate technical factors, patient positioning, and physiological conditions may be applicable to a particular image processing or machine learning task. Automatic labeling is important to make big data mining practical by replacing conventional manual review of every single-image series. Digital imaging and communications in medicine headers usually do not provide all the necessary labels and are sometimes incorrect. We propose an image-based high throughput labeling pipeline using deep learning, aimed at identifying scan direction, scan posture, lung coverage, contrast usage, and breath-hold types. They were posed as different classification problems and some of them involved further segmentation and identification of anatomic landmarks. Images of different view planes were used depending on the specific classification problem. All of our models achieved accuracy > 99 % on test set across different tasks using a research database from multicenter clinical trials.
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Affiliation(s)
- Xiaoyong Wang
- University of California, Los Angeles, Center for Computer Vision and Imaging Biomarkers, Los Angeles, California, United States.,University of California, Los Angeles, Department of Radiological Sciences, Los Angeles, California, United States
| | - Pangyu Teng
- University of California, Los Angeles, Center for Computer Vision and Imaging Biomarkers, Los Angeles, California, United States.,University of California, Los Angeles, Department of Radiological Sciences, Los Angeles, California, United States
| | - Ashley Ontiveros
- University of California, Los Angeles, Center for Computer Vision and Imaging Biomarkers, Los Angeles, California, United States.,University of California, Los Angeles, Department of Radiological Sciences, Los Angeles, California, United States
| | - Jonathan G Goldin
- University of California, Los Angeles, Center for Computer Vision and Imaging Biomarkers, Los Angeles, California, United States.,University of California, Los Angeles, Department of Radiological Sciences, Los Angeles, California, United States
| | - Matthew S Brown
- University of California, Los Angeles, Center for Computer Vision and Imaging Biomarkers, Los Angeles, California, United States.,University of California, Los Angeles, Department of Radiological Sciences, Los Angeles, California, United States
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Feldhaus FW, Theilig DC, Hubner RH, Kuhnigk JM, Neumann K, Doellinger F. Quantitative CT analysis in patients with pulmonary emphysema: is lung function influenced by concomitant unspecific pulmonary fibrosis? Int J Chron Obstruct Pulmon Dis 2019; 14:1583-1593. [PMID: 31409984 PMCID: PMC6646798 DOI: 10.2147/copd.s204007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 05/16/2019] [Indexed: 11/30/2022] Open
Abstract
Purpose Quantitative analysis of CT scans has proven to be a reproducible technique, which might help to understand the pathophysiology of chronic obstructive pulmonary disease (COPD) and combined pulmonary fibrosis and emphysema. The aim of this retrospective study was to find out if the lung function of patients with COPD with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages III or IV and pulmonary emphysema is measurably influenced by high attenuation areas as a correlate of concomitant unspecific fibrotic changes of lung parenchyma. Patients and methods Eighty-eight patients with COPD GOLD stage III or IV underwent CT and pulmonary function tests. Quantitative CT analysis was performed to determine low attenuation volume (LAV) and high attenuation volume (HAV), which are considered to be equivalents of fibrotic (HAV) and emphysematous (LAV) changes of lung parenchyma. Both parameters were determined for the whole lung, as well as peripheral and central lung areas only. Multivariate regression analysis was used to correlate HAV with different parameters of lung function. Results Unlike LAV, HAV did not show significant correlation with parameters of lung function. Even in patients with a relatively high HAV of more than 10%, in contrast to HAV (p=0.786) only LAV showed a significantly negative correlation with forced expiratory volume in 1 second (r=-0.309, R2=0.096, p=0.003). A severe decrease of DLCO% was associated with both larger HAV (p=0.045) and larger LAV (p=0.001). Residual volume and FVC were not influenced by LAV or HAV. Conclusion In patients with COPD GOLD stage III-IV, emphysematous changes of lung parenchyma seem to have such a strong influence on lung function, which is a possible effect of concomitant unspecific fibrosis is overwhelmed.
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Affiliation(s)
- Felix W Feldhaus
- Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Radiology, Berlin, Germany
| | - Dorothea Cornelia Theilig
- Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Radiology, Berlin, Germany
| | - Ralf-Harto Hubner
- Department of Internal Medicine/Infectious and Respiratory Disease, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Jan-Martin Kuhnigk
- Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen, Germany
| | - Konrad Neumann
- Institute of Biometrics and Clinical Epidemiology, Charité Universitätsmedizin Berlin, Berlin, Gemany
| | - Felix Doellinger
- Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Department of Radiology, Berlin, Germany
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Effects of acquisition method and reconstruction algorithm for CT number measurement on standard-dose CT and reduced-dose CT: a QIBA phantom study. Jpn J Radiol 2019; 37:399-411. [DOI: 10.1007/s11604-019-00823-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 02/17/2019] [Indexed: 11/24/2022]
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12
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Malherbe ST, Dupont P, Kant I, Ahlers P, Kriel M, Loxton AG, Chen RY, Via LE, Thienemann F, Wilkinson RJ, Barry CE, Griffith-Richards S, Ellman A, Ronacher K, Winter J, Walzl G, Warwick JM. A semi-automatic technique to quantify complex tuberculous lung lesions on 18F-fluorodeoxyglucose positron emission tomography/computerised tomography images. EJNMMI Res 2018; 8:55. [PMID: 29943161 PMCID: PMC6020088 DOI: 10.1186/s13550-018-0411-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/08/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND There is a growing interest in the use of 18F-FDG PET-CT to monitor tuberculosis (TB) treatment response. However, TB causes complex and widespread pathology, which is challenging to segment and quantify in a reproducible manner. To address this, we developed a technique to standardise uptake (Z-score), segment and quantify tuberculous lung lesions on PET and CT concurrently, in order to track changes over time. We used open source tools and created a MATLAB script. The technique was optimised on a training set of five pulmonary tuberculosis (PTB) cases after standard TB therapy and 15 control patients with lesion-free lungs. RESULTS We compared the proposed method to a fixed threshold (SUV > 1) and manual segmentation by two readers and piloted the technique successfully on scans of five control patients and five PTB cases (four cured and one failed treatment case), at diagnosis and after 1 and 6 months of treatment. There was a better correlation between the Z-score-based segmentation and manual segmentation than SUV > 1 and manual segmentation in terms of overall spatial overlap (measured in Dice similarity coefficient) and specificity (1 minus false positive volume fraction). However, SUV > 1 segmentation appeared more sensitive. Both the Z-score and SUV > 1 showed very low variability when measuring change over time. In addition, total glycolytic activity, calculated using segmentation by Z-score and lesion-to-background ratio, correlated well with traditional total glycolytic activity calculations. The technique quantified various PET and CT parameters, including the total glycolytic activity index, metabolic lesion volume, lesion volumes at different CT densities and combined PET and CT parameters. The quantified metrics showed a marked decrease in the cured cases, with changes already apparent at month one, but remained largely unchanged in the failed treatment case. CONCLUSIONS Our technique is promising to segment and quantify the lung scans of pulmonary tuberculosis patients in a semi-automatic manner, appropriate for measuring treatment response. Further validation is required in larger cohorts.
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Affiliation(s)
- Stephanus T. Malherbe
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Patrick Dupont
- Department of Neurosciences, Laboratory for Cognitive Neurology, KU Leuven, Belgium
- Division of Nuclear Medicine, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Ilse Kant
- Division of Nuclear Medicine, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Petri Ahlers
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Magdalena Kriel
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - André G. Loxton
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Ray Y. Chen
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
| | - Laura E. Via
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Science, University of Cape Town, Observatory, 7925 Republic of South Africa
| | - Friedrich Thienemann
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Science, University of Cape Town, Observatory, 7925 Republic of South Africa
- Department of Medicine, Faculty of Health Science, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa
| | - Robert J. Wilkinson
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Science, University of Cape Town, Observatory, 7925 Republic of South Africa
- Department of Medicine, Faculty of Health Science, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa
- The Francis Crick Institute, Midland Road, London, NW1 2AT UK
- Department of Medicine, Imperial College London, London, W2 1PG UK
| | - Clifton E. Barry
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD USA
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Science, University of Cape Town, Observatory, 7925 Republic of South Africa
| | - Stephanie Griffith-Richards
- Division of Radiodiagnosis, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Annare Ellman
- Division of Nuclear Medicine, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Katharina Ronacher
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
- Translational Research Institute, Mater Research Institute – The University of Queensland, Brisbane, QLD Australia
| | - Jill Winter
- Catalysis Foundation for Health, Emeryville, CA USA
| | - Gerhard Walzl
- DDST-NRF Centre of Excellence for Biomedical Tuberculosis Research and South African Medical Research Council Centre for Tuberculosis Research, Cape Town, South Africa
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - James M. Warwick
- Division of Nuclear Medicine, Department of Medical Imaging and Clinical Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Malherbe ST, Kleynhans L, Walzl G. The potential of imaging tools as correlates of infection and disease for new TB vaccine development. Semin Immunol 2018; 39:73-80. [PMID: 29914653 DOI: 10.1016/j.smim.2018.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 06/07/2018] [Indexed: 12/17/2022]
Abstract
The development of an improved vaccine to stimulate an effective response against Mycobacterium tuberculosis (MTB) infection and disease will be a major breakthrough in the fight against TB. A lack of tools to adequately track the progression or resolution of events in TB pathogenesis that occur at bacterial loads below the threshold for culture in human samples seriously hampers vaccine development and evaluation. In this review we discuss recent studies that use new imaging applications, modalities and analysis techniques to provide insight into the dynamic processes of MTB infection and disease that are challenging to monitor. These include early infection, the spectrum of latency and subclinical disease, the paucibacillary state induced by treatment, and events leading to recurrence, including relapse.
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Affiliation(s)
- Stephanus T Malherbe
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Léanie Kleynhans
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Gerhard Walzl
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
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Brown RH, Henderson RJ, Sugar EA, Holbrook JT, Wise RA. Reproducibility of airway luminal size in asthma measured by HRCT. J Appl Physiol (1985) 2017; 123:876-883. [PMID: 28705995 DOI: 10.1152/japplphysiol.00307.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/16/2017] [Accepted: 07/10/2017] [Indexed: 11/22/2022] Open
Abstract
Brown RH, Henderson RJ, Sugar EA, Holbrook JT, Wise RA, on behalf of the American Lung Association Airways Clinical Research Centers. Reproducibility of airway luminal size in asthma measured by HRCT. J Appl Physiol 123: 876-883, 2017. First published July 13, 2017; doi:10.1152/japplphysiol.00307.2017.-High-resolution CT (HRCT) is a well-established imaging technology used to measure lung and airway morphology in vivo. However, there is a surprising lack of studies examining HRCT reproducibility. The CPAP Trial was a multicenter, randomized, three-parallel-arm, sham-controlled 12-wk clinical trial to assess the use of a nocturnal continuous positive airway pressure (CPAP) device on airway reactivity to methacholine. The lack of a treatment effect of CPAP on clinical or HRCT measures provided an opportunity for the current analysis. We assessed the reproducibility of HRCT imaging over 12 wk. Intraclass correlation coefficients (ICCs) were calculated for individual airway segments, individual lung lobes, both lungs, and air trapping. The ICC [95% confidence interval (CI)] for airway luminal size at total lung capacity ranged from 0.95 (0.91, 0.97) to 0.47 (0.27, 0.69). The ICC (95% CI) for airway luminal size at functional residual capacity ranged from 0.91 (0.85, 0.95) to 0.32 (0.11, 0.65). The ICC measurements for airway distensibility index and wall thickness were lower, ranging from poor (0.08) to moderate (0.63) agreement. The ICC for air trapping at functional residual capacity was 0.89 (0.81, 0.94) and varied only modestly by lobe from 0.76 (0.61, 0.87) to 0.95 (0.92, 0.97). In stable well-controlled asthmatic subjects, it is possible to reproducibly image unstimulated airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability.NEW & NOTEWORTHY There is a surprising lack of studies examining the reproducibility of high-resolution CT in asthma. The current study examined reproducibility of airway measurements. In stable well-controlled asthmatic subjects, it is possible to reproducibly image airway luminal areas over time, by region, and by size at total lung capacity throughout the lungs. Therefore, any changes in luminal size on repeat CT imaging are more likely due to changes in disease state and less likely due to normal variability.
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Affiliation(s)
- Robert H Brown
- Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland; .,Department of Radiology, The Johns Hopkins Medical Institutions, Baltimore, Maryland.,Division of Pulmonary Medicine, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland.,Department of Environmental Health and Engineering, The Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Robert J Henderson
- Department of Epidemiology, The Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Elizabeth A Sugar
- Department of Biostatistics, The Johns Hopkins Medical Institutions, Baltimore, Maryland; and
| | - Janet T Holbrook
- Department of Epidemiology, The Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Robert A Wise
- Division of Pulmonary Medicine, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland
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Crossley D, Turner A, Subramanian D. Phenotyping emphysema and airways disease: Clinical value of quantitative radiological techniques. World J Respirol 2017; 7:1-16. [DOI: 10.5320/wjr.v7.i1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/23/2016] [Accepted: 01/14/2017] [Indexed: 02/06/2023] Open
Abstract
The pathophysiology of chronic obstructive pulmonary disease (COPD) and Alpha one antitrypsin deficiency is increasingly recognised as complex such that lung function alone is insufficient for early detection, clinical categorisation and dictating management. Quantitative imaging techniques can detect disease earlier and more accurately, and provide an objective tool to help phenotype patients into predominant airways disease or emphysema. Computed tomography provides detailed information relating to structural and anatomical changes seen in COPD, and magnetic resonance imaging/nuclear imaging gives functional and regional information with regards to ventilation and perfusion. It is likely imaging will become part of routine clinical practice, and an understanding of the implications of the data is essential. This review discusses technical and clinical aspects of quantitative imaging in obstructive airways disease.
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Chen-Mayer HH, Fuld MK, Hoppel B, Judy PF, Sieren JP, Guo J, Lynch DA, Possolo A, Fain SB. Standardizing CT lung density measure across scanner manufacturers. Med Phys 2017; 44:974-985. [PMID: 28060414 DOI: 10.1002/mp.12087] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 12/13/2016] [Accepted: 12/22/2016] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Computed Tomography (CT) imaging of the lung, reported in Hounsfield Units (HU), can be parameterized as a quantitative image biomarker for the diagnosis and monitoring of lung density changes due to emphysema, a type of chronic obstructive pulmonary disease (COPD). CT lung density metrics are global measurements based on lung CT number histograms, and are typically a quantity specifying either the percentage of voxels with CT numbers below a threshold, or a single CT number below which a fixed relative lung volume, nth percentile, falls. To reduce variability in the density metrics specified by CT attenuation, the Quantitative Imaging Biomarkers Alliance (QIBA) Lung Density Committee has organized efforts to conduct phantom studies in a variety of scanner models to establish a baseline for assessing the variations in patient studies that can be attributed to scanner calibration and measurement uncertainty. METHODS Data were obtained from a phantom study on CT scanners from four manufacturers with several protocols at various tube potential voltage (kVp) and exposure settings. Free from biological variation, these phantom studies provide an assessment of the accuracy and precision of the density metrics across platforms solely due to machine calibration and uncertainty of the reference materials. The phantom used in this study has three foam density references in the lung density region, which, after calibration against a suite of Standard Reference Materials (SRM) foams with certified physical density, establishes a HU-electron density relationship for each machine-protocol. We devised a 5-step calibration procedure combined with a simplified physical model that enabled the standardization of the CT numbers reported across a total of 22 scanner-protocol settings to a single energy (chosen at 80 keV). A standard deviation was calculated for overall CT numbers for each density, as well as by scanner and other variables, as a measure of the variability, before and after the standardization. In addition, a linear mixed-effects model was used to assess the heterogeneity across scanners, and the 95% confidence interval of the mean CT number was evaluated before and after the standardization. RESULTS We show that after applying the standardization procedures to the phantom data, the instrumental reproducibility of the CT density measurement of the reference foams improved by more than 65%, as measured by the standard deviation of the overall mean CT number. Using the lung foam that did not participate in the calibration as a test case, a mixed effects model analysis shows that the 95% confidence intervals are [-862.0 HU, -851.3 HU] before standardization, and [-859.0 HU, -853.7 HU] after standardization to 80 keV. This is in general agreement with the expected CT number value at 80 keV of -855.9 HU with 95% CI of [-857.4 HU, -854.5 HU] based on the calibration and the uncertainty in the SRM certified density. CONCLUSIONS This study provides a quantitative assessment of the variations expected in CT lung density measures attributed to non-biological sources such as scanner calibration and scanner x-ray spectrum and filtration. By removing scanner-protocol dependence from the measured CT numbers, higher accuracy and reproducibility of quantitative CT measures were attainable. The standardization procedures developed in study may be explored for possible application in CT lung density clinical data.
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Affiliation(s)
- Huaiyu Heather Chen-Mayer
- Radiation Physics Division, Physical Measurements Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Matthew K Fuld
- Siemens Medical Solutions USA Inc., Malvern, PA, 19355, USA
| | - Bernice Hoppel
- Toshiba Medical Research Institute USA Inc., Vernon Hills, IL, 60061, USA
| | - Philip F Judy
- Department of Radiology, Brigham & Women's Hospital, Boston, MA, 02115, USA
| | | | - Junfeng Guo
- Departments of Radiology and Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - David A Lynch
- Department of Radiology, National Jewish Health, Denver, CO, 80206, USA
| | - Antonio Possolo
- Statistical Engineering Division, Information Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Sean B Fain
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53705, USA
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Karimi R, Tornling G, Forsslund H, Mikko M, Wheelock ÅM, Nyrén S, Sköld CM. Differences in regional air trapping in current smokers with normal spirometry. Eur Respir J 2017; 49:49/1/1600345. [DOI: 10.1183/13993003.00345-2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 10/13/2016] [Indexed: 12/20/2022]
Abstract
We investigated regional air trapping on computed tomography in current smokers with normal spirometry. It was hypothesised that presence of regional air trapping may indicate a specific manifestation of smoking-related changes.40 current smokers, 40 patients with chronic obstructive pulmonary disease (COPD), and 40 healthy never- smokers underwent computed tomography scans. Regional air trapping was assessed on end-expiratory scans and emphysema, micronodules and bronchial wall thickening on inspiratory scans. The ratio of expiratory and inspiratory mean lung attenuation (E/I) was calculated as a measure of static (fixed) air trapping.Regional air trapping was present in 63% of current smokers, in 45% of never smokers and in 8% of COPD patients (p<0.001). Current smokers with and without regional air trapping had E/I ratio of 0.81 and 0.91, respectively (p<0.001). Forced expiratory volume in 1 s (FEV1) was significantly higher and emphysema less frequent in current smokers with regional air trapping.Current smokers with regional air trapping had higher FEV1 and less emphysema on computed tomography. In contrast, current smokers without regional air trapping resembled COPD. Our results highlight heterogeneity among smokers with normal spirometry and may contribute to early detection of smoking related structural changes in the lungs.
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Raghu G, Scholand MB, de Andrade J, Lancaster L, Mageto Y, Goldin J, Brown KK, Flaherty KR, Wencel M, Wanger J, Neff T, Valone F, Stauffer J, Porter S. FG-3019 anti-connective tissue growth factor monoclonal antibody: results of an open-label clinical trial in idiopathic pulmonary fibrosis. Eur Respir J 2016; 47:1481-91. [PMID: 26965296 DOI: 10.1183/13993003.01030-2015] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 01/11/2016] [Indexed: 12/20/2022]
Abstract
FG-3019 is a fully human monoclonal antibody that interferes with the action of connective tissue growth factor, a central mediator in the pathogenesis of fibrosis.This open-label phase 2 trial evaluated the safety and efficacy of two doses of FG-3019 administered by intravenous infusion every 3 weeks for 45 weeks in patients with idiopathic pulmonary fibrosis (IPF). Subjects had a diagnosis of IPF within the prior 5 years defined by either usual interstitial pneumonia (UIP) pattern on a recent high-resolution computed tomography (HRCT) scan, or a possible UIP pattern on HRCT scan and a recent surgical lung biopsy showing UIP pattern. Pulmonary function tests were performed every 12 weeks, and changes in the extent of pulmonary fibrosis were measured by quantitative HRCT scans performed at baseline and every 24 weeks.FG-3019 was safe and well-tolerated in IPF patients participating in the study. Changes in fibrosis were correlated with changes in pulmonary function.Further investigation of FG-3019 in IPF with a placebo-controlled clinical trial is warranted and is underway.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Jack Wanger
- Pulmonary Function and Clinical Trial Consultant, Rochester, MN, USA
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Nemec SF, Molinari F, Dufresne V, Gosset N, Silva M, Bankier AA. Comparison of four software packages for CT lung volumetry in healthy individuals. Eur Radiol 2015; 25:1588-97. [DOI: 10.1007/s00330-014-3557-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 10/27/2014] [Accepted: 12/04/2014] [Indexed: 11/24/2022]
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Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers. Respir Res 2014; 15:23. [PMID: 24564813 PMCID: PMC3944780 DOI: 10.1186/1465-9921-15-23] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 02/16/2014] [Indexed: 01/11/2023] Open
Abstract
Background Smokers have increased cell concentration in the lower respiratory tract indicating a chronic inflammatory state, which in some individuals may lead to development of chronic obstructive pulmonary disease (COPD). Computer tomography (CT) imaging provides means of quantifying pulmonary structure and early signs of disease. We investigated whether lung density on high resolution CT differs between smokers and never-smokers and if this were associated to intensity of inflammation. Methods Forty smoking volunteers with normal pulmonary function, 40 healthy never-smokers and 40 patients with COPD of GOLD stage I-II, were included. Mean lung attenuation and percentage of pixels in the lung with attenuation between −750 and −900 HU (percentage higher density spectrum (%HDS)) were calculated on inspiratory CT-scans. Markers of systemic inflammation in blood and cell counts in bronchoalveolar lavage (BAL) fluid were recorded. Results Lung density expressed as %HDS was increased in smokers (44.0 ± 5.8%) compared to both never-smokers (38.3 ± 5.8%) and patients with COPD (39.1 ± 5.8%), (p < 0.001, for both). Females had denser lungs than males, which was dependent on body height. Cell concentration in BAL were correlated to lung density in smokers (r = 0.50, p < 0.001). Conclusions Lung density on CT is associated with cell concentration in BAL in smokers and may mirror an inflammatory response in the lung. Gender difference in lung density is dependent on height. In COPD with emphysema, loss of lung tissue may counterbalance the expected increase in density due to inflammation. The findings may help to interpret high resolution CT in the context of smoking and gender and highlight the heterogeneity of structural changes in COPD.
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Jacob RE, Carson JP. Automated measurement of heterogeneity in CT images of healthy and diseased rat lungs using variogram analysis of an octree decomposition. BMC Med Imaging 2014; 14:1. [PMID: 24393332 PMCID: PMC3922839 DOI: 10.1186/1471-2342-14-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 12/18/2013] [Indexed: 12/23/2022] Open
Abstract
Background Assessing heterogeneity in lung images can be an important diagnosis tool. We present a novel and objective method for assessing lung damage in a rat model of emphysema. We combined a three-dimensional (3D) computer graphics method–octree decomposition–with a geostatistics-based approach for assessing spatial relationships–the variogram–to evaluate disease in 3D computed tomography (CT) image volumes. Methods Male, Sprague-Dawley rats were dosed intratracheally with saline (control), or with elastase dissolved in saline to either the whole lung (for mild, global disease) or a single lobe (for severe, local disease). Gated 3D micro-CT images were acquired on the lungs of all rats at end expiration. Images were masked, and octree decomposition was performed on the images to reduce the lungs to homogeneous blocks of 2 × 2 × 2, 4 × 4 × 4, and 8 × 8 × 8 voxels. To focus on lung parenchyma, small blocks were ignored because they primarily defined boundaries and vascular features, and the spatial variance between all pairs of the 8 × 8 × 8 blocks was calculated as the square of the difference of signal intensity. Variograms–graphs of distance vs. variance–were constructed, and results of a least-squares-fit were compared. The robustness of the approach was tested on images prepared with various filtering protocols. Statistical assessment of the similarity of the three control rats was made with a Kruskal-Wallis rank sum test. A Mann-Whitney-Wilcoxon rank sum test was used to measure statistical distinction between individuals. For comparison with the variogram results, the coefficient of variation and the emphysema index were also calculated for all rats. Results Variogram analysis showed that the control rats were statistically indistinct (p = 0.12), but there were significant differences between control, mild global disease, and severe local disease groups (p < 0.0001). A heterogeneity index was calculated to describe the difference of an individual variogram from the control average. This metric also showed clear separation between dose groups. The coefficient of variation and the emphysema index, on the other hand, did not separate groups. Conclusion These results suggest the octree decomposition and variogram analysis approach may be a rapid, non-subjective, and sensitive imaging-based biomarker for characterizing lung disease.
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Affiliation(s)
- Richard E Jacob
- Biological Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Blvd,, Richland, WA 99352, USA.
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Meinel FG, Schwab F, Schleede S, Bech M, Herzen J, Achterhold K, Auweter S, Bamberg F, Yildirim AÖ, Bohla A, Eickelberg O, Loewen R, Gifford M, Ruth R, Reiser MF, Pfeiffer F, Nikolaou K. Diagnosing and mapping pulmonary emphysema on X-ray projection images: incremental value of grating-based X-ray dark-field imaging. PLoS One 2013; 8:e59526. [PMID: 23555692 PMCID: PMC3608711 DOI: 10.1371/journal.pone.0059526] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 02/15/2013] [Indexed: 02/01/2023] Open
Abstract
PURPOSE To assess whether grating-based X-ray dark-field imaging can increase the sensitivity of X-ray projection images in the diagnosis of pulmonary emphysema and allow for a more accurate assessment of emphysema distribution. MATERIALS AND METHODS Lungs from three mice with pulmonary emphysema and three healthy mice were imaged ex vivo using a laser-driven compact synchrotron X-ray source. Median signal intensities of transmission (T), dark-field (V) and a combined parameter (normalized scatter) were compared between emphysema and control group. To determine the diagnostic value of each parameter in differentiating between healthy and emphysematous lung tissue, a receiver-operating-characteristic (ROC) curve analysis was performed both on a per-pixel and a per-individual basis. Parametric maps of emphysema distribution were generated using transmission, dark-field and normalized scatter signal and correlated with histopathology. RESULTS Transmission values relative to water were higher for emphysematous lungs than for control lungs (1.11 vs. 1.06, p<0.001). There was no difference in median dark-field signal intensities between both groups (0.66 vs. 0.66). Median normalized scatter was significantly lower in the emphysematous lungs compared to controls (4.9 vs. 10.8, p<0.001), and was the best parameter for differentiation of healthy vs. emphysematous lung tissue. In a per-pixel analysis, the area under the ROC curve (AUC) for the normalized scatter value was significantly higher than for transmission (0.86 vs. 0.78, p<0.001) and dark-field value (0.86 vs. 0.52, p<0.001) alone. Normalized scatter showed very high sensitivity for a wide range of specificity values (94% sensitivity at 75% specificity). Using the normalized scatter signal to display the regional distribution of emphysema provides color-coded parametric maps, which show the best correlation with histopathology. CONCLUSION In a murine model, the complementary information provided by X-ray transmission and dark-field images adds incremental diagnostic value in detecting pulmonary emphysema and visualizing its regional distribution as compared to conventional X-ray projections.
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Affiliation(s)
- Felix G Meinel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany.
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Mets OM, Isgum I, Mol CP, Gietema HA, Zanen P, Prokop M, de Jong PA. Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations. Eur Radiol 2012; 22:2710-7. [PMID: 22696157 PMCID: PMC3486998 DOI: 10.1007/s00330-012-2526-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 04/20/2012] [Accepted: 04/25/2012] [Indexed: 11/25/2022]
Abstract
Objectives To determine the variation in quantitative computed tomography (CT) measures of air trapping in low-dose chest CTs of heavy smokers. Methods We analysed 45 subjects from a lung cancer screening trial, examined by CT twice within 3 months. Inspiratory and expiratory low-dose CT was obtained using breath hold instructions. CT air trapping was defined as the percentage of voxels in expiratory CT with an attenuation below −856 HU (EXP−856) and the expiratory to inspiratory ratio of mean lung density (E/I-ratioMLD). Variation was determined using limits of agreement, defined as 1.96 times the standard deviation of the mean difference. The effect of both lung volume correction and breath hold reproducibility was determined. Results The limits of agreement for uncorrected CT air trapping measurements were −15.0 to 11.7 % (EXP−856) and −9.8 to 8.0 % (E/I-ratioMLD). Good breath hold reproducibility significantly narrowed the limits for EXP−856 (−10.7 to 7.5 %, P = 0.002), but not for E/I-ratioMLD (−9.2 to 7.9 %, P = 0.75). Statistical lung volume correction did not improve the limits for EXP−856 (−12.5 to 8.8 %, P = 0.12) and E/I-ratioMLD (−7.5 to 5.8 %, P = 0.17). Conclusions Quantitative air trapping measures on low-dose CT of heavy smokers show considerable variation on repeat CT examinations, regardless of lung volume correction or reproducible breath holds. Key Points • Computed tomography quantitatively measures small airways disease in heavy smokers. • Measurements of air trapping vary considerably on repeat CT examinations. • Variation remains substantial even with reproducible breath holds and lung volume correction.
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Affiliation(s)
- Onno M Mets
- Radiology, University Medical Center Utrecht, Heidelberglaan 100, Postbus 85500, 3508 GA, Utrecht, The Netherlands.
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