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Wilson FD, Mir TM, Ashfaq MK, Zhang J, Pugh ND, Khan IA, Pace LW, Hoerr FJ. Histomorphometric lung density evaluation of Immulina treatment using a murine influenza pneumonia model. Int J Exp Pathol 2023; 104:283-291. [PMID: 37750190 PMCID: PMC10652700 DOI: 10.1111/iep.12493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 08/08/2023] [Accepted: 08/17/2023] [Indexed: 09/27/2023] Open
Abstract
Histomorphometric lung density measurements were used to evaluate the effects of Immulina on mouse pneumonia. Mice were intra-nasally exposed to H1N1 influenza virus at a dose of 5 × 104 PFU/50 μL/mouse. Lung density was measured using the NIH ImageJ software program. Density values were compared to semiquantitative pneumonia severity scores. Lung photomicrographs were evaluated at 25-×, 40-× and 400-× magnification. The study included viral inoculated controls (IC) and non-inoculated controls (NC) and mice either treated or not treated with Immulina. Three doses of Immulina were included (25, 50 or 100 mg/kg) and administered using 3 protocols: prophylactic treatment (P), prodromal treatment (PD) and therapeutic treatment (TH) (note that in most of the evaluations of the data for the three treatment protocols were combined). Groups of mice were evaluated on days 3, 5, 7, 10 and 15 following exposure. The occurrence of "digital pneumonia" (DP) was defined as a density measurement above the 95% confidence limit of the corresponding NC values. A significant reduction in the occurrence of DP with Immulina treatment at the higher doses compared to IC was seen as early as day 3 and persisted up to day 15. There were also statistically significant dose-variable reductions in lung density in response to Immulina. The study suggests early administration of Immulina (P or PD protocols) may enhance resistance against influenza-induced viral pneumonia. A moderate correlation between pneumonia severity scores and lung density was observed for the 25-× and 40-× images (R = 0.56 and 0.53 respectively), and a strong correlation (R = 0.68) for 400-× images.
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Affiliation(s)
- Floyd D. Wilson
- Mississippi Veterinary Research and Diagnostic LaboratoryMississippi State UniversityPearlMississippiUSA
| | - Tahir M. Mir
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical SciencesUniversity of MississippiUniversityMississippiUSA
| | - Mohammad K. Ashfaq
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical SciencesUniversity of MississippiUniversityMississippiUSA
| | - Jin Zhang
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical SciencesUniversity of MississippiUniversityMississippiUSA
| | - Nirmal D. Pugh
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical SciencesUniversity of MississippiUniversityMississippiUSA
| | - Ikhlas A. Khan
- National Center for Natural Products Research, School of Pharmacy, Research Institute of Pharmaceutical SciencesUniversity of MississippiUniversityMississippiUSA
- Department of BioMolecular Sciences, School of PharmacyUniversity of MississippiUniversityMississippiUSA
| | - Lanny W. Pace
- Mississippi Veterinary Research and Diagnostic LaboratoryMississippi State UniversityPearlMississippiUSA
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Feitosa PH. Diagnosis and augmentation therapy for alpha-1 antitrypsin deficiency: current knowledge and future potential. Drugs Context 2023; 12:2023-3-1. [PMID: 37521109 PMCID: PMC10379007 DOI: 10.7573/dic.2023-3-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/19/2023] [Indexed: 08/01/2023] Open
Abstract
The underdiagnosis of alpha-1 antitrypsin (AAT) deficiency (AATD) has been recognized for many years, yet little progress has been made in treatment of the disease. In this review, we summarize the AATD disease process as well as its diagnosis and treatment by AAT augmentation therapy. AATD is a rare autosomal disease that primarily affects the lungs and liver. AATD is associated with an increased susceptibility to developing pulmonary emphysema. The specific pharmacological treatment for AATD is intravenous administration of exogenous AAT. Augmentation therapy with AAT increases serum and pulmonary epithelial AAT levels, restores anti-elastase capacity, and decreases inflammatory mediators in the lung. Augmentation therapy reduces the loss of lung density over time, thus slowing progression of the disease. The effects of augmentation therapy on outcomes, such as frequency/duration of flare-ups, quality of life, lung function decline and mortality, are assessed. Wider testing for AATD, potentially through primary care physicians, could result in earlier treatment and better outcomes for individuals with AATD-induced lung respiratory disease.
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Godbole S, Labaki WW, Pratte KA, Hill A, Moll M, Hastie AT, Peters SP, Gregory A, Ortega VE, DeMeo D, Cho MH, Bhatt SP, Wells JM, Barjaktarevic I, Stringer KA, Comellas A, O’Neal W, Kechris K, Bowler RP. A Metabolomic Severity Score for Airflow Obstruction and Emphysema. Metabolites 2022; 12:metabo12050368. [PMID: 35629872 PMCID: PMC9143560 DOI: 10.3390/metabo12050368] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/07/2022] [Indexed: 01/21/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a disease with marked metabolic disturbance. Previous studies have shown the association between single metabolites and lung function for COPD, but whether a combination of metabolites could predict phenotype is unknown. We developed metabolomic severity scores using plasma metabolomics from the Metabolon platform from two US cohorts of ever-smokers: the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) (n = 648; training/testing cohort; 72% non-Hispanic, white; average age 63 years) and the COPDGene Study (n = 1120; validation cohort; 92% non-Hispanic, white; average age 67 years). Separate adaptive LASSO (adaLASSO) models were used to model forced expiratory volume at one second (FEV1) and MESA-adjusted lung density using 762 metabolites common between studies. Metabolite coefficients selected by the adaLASSO procedure were used to create a metabolomic severity score (metSS) for each outcome. A total of 132 metabolites were selected to create a metSS for FEV1. The metSS-only models explained 64.8% and 31.7% of the variability in FEV1 in the training and validation cohorts, respectively. For MESA-adjusted lung density, 129 metabolites were selected, and metSS-only models explained 59.0% of the variability in the training cohort and 17.4% in the validation cohort. Regression models including both clinical covariates and the metSS explained more variability than either the clinical covariate or metSS-only models (53.4% vs. 46.4% and 31.6%) in the validation dataset. The metabolomic pathways for arginine biosynthesis; aminoacyl-tRNA biosynthesis; and glycine, serine, and threonine pathway were enriched by adaLASSO metabolites for FEV1. This is the first demonstration of a respiratory metabolomic severity score, which shows how a metSS can add explanation of variance to clinical predictors of FEV1 and MESA-adjusted lung density. The advantage of a comprehensive metSS is that it explains more disease than individual metabolites and can account for substantial collinearity among classes of metabolites. Future studies should be performed to determine whether metSSs are similar in younger, and more racially and ethnically diverse populations as well as whether a metabolomic severity score can predict disease development in individuals who do not yet have COPD.
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Affiliation(s)
- Suneeta Godbole
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
- Correspondence:
| | - Wassim W. Labaki
- Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109, USA; (W.W.L.); (K.A.S.)
| | - Katherine A. Pratte
- Division of Medicine, National Jewish Health, Denver, CO 80206, USA; (K.A.P.); (A.H.); (R.P.B.)
| | - Andrew Hill
- Division of Medicine, National Jewish Health, Denver, CO 80206, USA; (K.A.P.); (A.H.); (R.P.B.)
| | - Matthew Moll
- Channing Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA; (M.M.); (D.D.); (M.H.C.)
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - Annette T. Hastie
- Section on Pulmonary, Critical Care, Allergy & Immunology, Internal Medicine, Wake Forest School of Medicine, Winston Salem, NC 27157, USA;
| | - Stephen P. Peters
- Section on Pulmonary, Critical Care, Allergy & Immunology, Internal Medicine, Atrium Health Wake Forest Baptist, Winston Salem, NC 20157, USA;
| | - Andrew Gregory
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - Victor E. Ortega
- Division of Respiratory Medicine, Department of Internal Medicine, Center for Individualized Medicine, Mayo Clinic, Scottsdale, AZ 85259, USA;
| | - Dawn DeMeo
- Channing Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA; (M.M.); (D.D.); (M.H.C.)
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - Michael H. Cho
- Channing Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA; (M.M.); (D.D.); (M.H.C.)
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, MA 02115, USA;
| | - Surya P. Bhatt
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - J. Michael Wells
- UAB Lung Health Center, Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Igor Barjaktarevic
- Division of Pulmonary and Critical Care, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA;
| | - Kathleen A. Stringer
- Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109, USA; (W.W.L.); (K.A.S.)
- Department of Clinical Pharmacy and the NMR Metabolomics Laboratory, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alejandro Comellas
- Division of Pulmonary and Critical Care, University of Iowa, Iowa City, IA 52242, USA;
| | - Wanda O’Neal
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Katerina Kechris
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - Russell P. Bowler
- Division of Medicine, National Jewish Health, Denver, CO 80206, USA; (K.A.P.); (A.H.); (R.P.B.)
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Fakhouri F, Kannengiesser S, Pfeuffer J, Gokun Y, Kolipaka A. Free-breathing MR elastography of the lungs: An in vivo study. Magn Reson Med 2022; 87:236-248. [PMID: 34463400 PMCID: PMC8616792 DOI: 10.1002/mrm.28986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 01/03/2023]
Abstract
PURPOSE Lung stiffness alters with many diseases; therefore, several MR elastography (MRE) studies were performed earlier to investigate the stiffness of the right lung during breathhold at residual volume and total lung capacity. The aims of this study were 1) to estimate shear stiffness of the lungs using MRE under free breathing and demonstrate the measurements' repeatability and reproducibility, and 2) to compare lung stiffness under free breathing to breathhold and as a function of age and gender. METHODS Twenty-five healthy volunteers were scanned on a 1.5 Tesla MRI scanner. Spin-echo dual-density spiral and a spin-echo EPI MRE sequences were used to measure shear stiffness of the lungs during free breathing and breathhold at midpoint of tidal volume, respectively. Concordance correlation coefficient and Bland-Altman analyses were performed to determine the repeatability and reproducibility of the spin-echo dual-density spiral-derived shear stiffness. Repeated measures analyses of variances were used to investigate differences in shear stiffness between spin-echo dual-density spiral and spin-echo EPI, right and left lungs, males and females, and different age groups. RESULTS Free-breathing MRE sequence was highly repeatable and reproducible (concordance correlation coefficient > 0.86 for both lungs). Lung stiffness was significantly lower in breathhold than in free breathing (P < .001), which can be attributed to potential stress relaxation of lung parenchyma or breathhold inconsistencies. However, there was no significant difference between different age groups (P = .08). The left lung showed slightly higher stiffness values than the right lung (P = .14). There is no significant difference in lung stiffness between genders. CONCLUSION This study demonstrated the feasibility of free-breathing lung MRE with excellent repeatability and reproducibility. Stiffness changes with age and during the respiratory cycle. However, gender does not influence lungs stiffness.
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Affiliation(s)
- Faisal Fakhouri
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA.,Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | | | - Josef Pfeuffer
- MR Application Development, Siemens Healthcare GmbH, Erlangen, Germany
| | - Yevgeniya Gokun
- Department of Biomedical Informatics, Center for Biostatistics, The Ohio State University, Columbus, OH 43210, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA.,Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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Sarioglu FC, Gezer NS, Odaman H, Sarioglu O, Ulusoy O, Ates O, Guleryuz H. Lung density analysis using quantitative computed tomography in children with pectus excavatum. Pol J Radiol 2021; 86:e372-9. [PMID: 34322187 DOI: 10.5114/pjr.2021.107685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 01/14/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose To evaluate the mean lung density in children with pectus excavatum (PE) and to assess the correlation between the cardiac rotation angle, Haller index, pulmonary function test, and lung density. Material and methods This retrospective study included 33 children with PE and 31 healthy controls. The densities of lung parenchyma were evaluated by quantitative computed tomography (CT). Three lung levels were determined: T4 vertebra level, T10 vertebra level, and the level of the measurement of the cardiac rotation angle. The cardiac rotation angle and the Haller index were calculated. All measurements were done by 2 radiologists, independently. Student’s t-test or the Mann-Whitney U test, intraclass correlation coefficients, Pearson or Spearman’s rank correlation coefficient, and Kruskal-Wallis test were used for statistical analysis. A p-value less than 0.05 was considered as statistically significant. Results All the lung levels in the PE group had lower mean densities than healthy children, with statistical significance in the right lung at the T10 vertebra level (−818.60 ± 33.49 HU, −798.45 ± 40.24 HU; p = 0.028). There was a correlation between the cardiac rotation angle and the Haller index (r = 0.593; p < 0.001). There were no correlations between mean lung density and cardiac rotation angle, Haller index, and pulmonary function tests. Conclusions The lower mean lung densities were found in PE, especially in the right lower lobe. The parenchymal aeration should be considered independently from the severity of PE.
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Kirby M, Hatt C, Obuchowski N, Humphries SM, Sieren J, Lynch DA, Fain SB. Inter- and intra-software reproducibility of computed tomography lung density measurements. Med Phys 2020; 47:2962-2969. [PMID: 32160310 DOI: 10.1002/mp.14130] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Multiple commercial, open-source, and academic software tools exist for objective quantification of lung density in computed tomography (CT) images. The purpose of this study was to evaluate the intersoftware reproducibility of CT lung density measurements. METHODS Computed tomography images from 50 participants from the COPDGeneTM cohort study were randomly selected for analysis; n = 10 participants across each global initiative for chronic obstructive lung disease (GOLD) grade (GOLD 0-IV). Academic-based groups (n = 4) and commercial vendors (n = 4) participated anonymously to generate CT lung density measurements using their software tools. Computed tomography total lung volume (TLV), percentage of the low attenuation areas in the lung with Hounsfield unit (HU) values below -950HU (LAA950 ), and the HU value corresponding to the 15th percentile on the parenchymal density histogram (Perc15) were included in the analysis. The intersoftware bias and reproducibility coefficient (RDC) was generated with and without quality assurance (QA) for manual correction of the lung segmentation; intrasoftware bias and RDC was also generated by repeated measurements on the same images. RESULTS Intersoftware mean bias was within ±0.22 mL, ±0.46%, and ±0.97 HU for TLV, LAA950 and Perc15, respectively. The RDC was 0.35 L, 1.2% and 1.8 HU for TLV, LAA950 and Perc15, respectively. Intersoftware RDC remained unchanged following QA: 0.35 L, 1.2% and 1.8 HU for TLV, LAA950 and Perc15, respectively. All software investigated had an intrasoftware RDC of 0. The RDC was comparable for TLV, LAA950 and Perc15 measurements, respectively, for academic-based groups/commercial vendor-based software tools: 0.39 L/0.32 L, 1.2%/1.2%, and 1.7 HU/1.6 HU. Multivariable regression analysis showed that academic-based software tools had greater within-subject standard deviation of TLV than commercial vendors, but no significant differences between academic and commercial groups were found for LAA950 or Perc15 measurements. CONCLUSIONS Computed tomography total lung volume and lung density measurement bias and reproducibility was reported across eight different software tools. Bias was negligible across vendors, reproducibility was comparable for software tools generated by academic-based groups and commercial vendors, and segmentation QA had negligible impact on measurement variability between software tools. In summary, results from this study report the amount of additional measurement variability that should be accounted for when using different software tools to measure lung density longitudinally with well-standardized image acquisition protocols. However, intrasoftware reproducibility was deterministic for all cases so use of the same software tool to reduce variability for serial studies is highly recommended.
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Affiliation(s)
- Miranda Kirby
- Department of Physics, Ryerson University, Toronto, ON, Canada
| | - Charles Hatt
- IMBIO, Minneapolis, MN, USA.,Deparment of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Nancy Obuchowski
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA
| | | | | | - David A Lynch
- Department of Radiology, National Jewish Health, Denver, CO, USA
| | - Sean B Fain
- Deparment of Medical Physics, University of Wisconsin, Madison, WI, USA
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7
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Muramatsu S. [Method for Spectral Analysis of the Respiratory Cycle Based on Dynamic Pulmonary Computed Tomography]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2020; 76:1017-1024. [PMID: 33087647 DOI: 10.6009/jjrt.2020_jsrt_76.10.1017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dynamic pulmonary computed tomography (CT) enables morphological analyses of tumor adhesion and infiltration and functional analyses of the lungs based on four-dimensional data. However, the functional analysis requires visualization of the respiratory cycle. The aim of the present study was to investigate the utility of spectral analysis as part of the functional analysis of the lungs based on dynamic pulmonary CT. In this study, the reference curves for the respiratory cycle were obtained using measurements of all phases of respiration based on the movement of the diaphragm. The reference curves and fields of the unaffected lung were divided into three sections: upper, middle, and lower. The central position within each lung field in the axial section was used as the fixed location, and the lung field concentrations (CT values within each lung field) were measured. Using the maximum entropy (ME) method, the spectral analysis was performed for the lung field concentration curves obtained in this manner. The investigated items were the peak frequency in the power spectrum based on the ME analysis of the reference curve and the time difference from this peak frequency in the upper, middle, and lower lung field concentration curves. The time differences (median±standard deviation) from the reference values were 0.18±0.20, 0.34±0.33, and 0.34±0.35 s in the upper, middle, and lower lung fields, respectively, indicating the smallest time difference in the upper lung field. Performing spectral analysis using the ME method on lung field concentration curves enables assessment of the respiratory cycle based on dynamic pulmonary CT, and this approach is consistent with the visual assessment of the respiratory cycle.
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Garpered S, Minarik D, Diaz S, Valind S, Edenbrandt L, Wollmer P. Measurement of airway inflammation in current smokers by positron emission tomography. Clin Physiol Funct Imaging 2019; 39:393-398. [PMID: 31278814 DOI: 10.1111/cpf.12590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 06/27/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Accumulation of activated neutrophilic leucocytes is known to increase uptake of 18 F-fluorodeoxyglucose (18 F-FDG) into lung tissue. Available evidence suggests that smokers and subjects with chronic obstructive pulmonary disease (COPD) have neutrophilic inflammation in peripheral airways. The aim of this study was to examine whether current smokers have higher lung tissue uptake of 18 F-FDG than never-smokers when correcting for air fraction of the lungs. METHODS We prospectively recruited 33 current smokers and 33 never-smokers among subjects referred for diagnosis or staging of cancer, other than lung cancer, with combined positron emission tomography/computed tomography (PET/CT) with 18 F-FDG. Subjects with focal 18 F-FDG uptake or focal CT abnormalities in the lungs were excluded. The lungs were segmented in the CT image, and lung density measured. 18 F-FDG uptake was measured in the corresponding volume and corrected for air fraction. RESULTS Lung uptake of 18 F-FDG, corrected for air fraction, was 12·5 and 8 per cent higher in the right and left lungs, respectively, in current smokers than in never-smokers (P<0·05). Conclusion Abnormal lung tissue uptake of 18 F-FDG may be masked by reduced lung density if the uptake is not related to air fraction. Increased uptake of 18 F-FDG in lung tissue in current smokers relative to never-smokers may reflect inflammation in peripheral airways. Measurements of 18 F-FDG uptake in the lung tissue may be useful for animal and human studies of airways disease in COPD and the relation between airway and systemic inflammation.
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Affiliation(s)
- Sabine Garpered
- Clinical Physiology and Nuclear Medicine Unit, Department of Translational Medicine, Lund University, Lund, Sweden
| | - David Minarik
- Department of Radiation Physics, Skane University Hospital Malmö, Malmö, Sweden
| | - Sandra Diaz
- Department of Radiology, Skane University Hospital Malmö, Malmö, Sweden
| | - Sven Valind
- Clinical Physiology and Nuclear Medicine Unit, Department of Translational Medicine, Lund University, Lund, Sweden
| | - Lars Edenbrandt
- Sahlgrenska Hospital Nuclear Medicine Unit, University Gothenburg, Gothenburg, Sweden
| | - Per Wollmer
- Clinical Physiology and Nuclear Medicine Unit, Department of Translational Medicine, Lund University, Lund, Sweden
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Vegas-Sánchez-Ferrero G, Ledesma-Carbayo MJ, Washko GR, San José Estépar R. Harmonization of chest CT scans for different doses and reconstruction methods. Med Phys 2019; 46:3117-3132. [PMID: 31069809 PMCID: PMC7251983 DOI: 10.1002/mp.13578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 03/25/2019] [Accepted: 04/22/2019] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To develop and validate a computed tomography (CT) harmonization technique by combining noise-stabilization and autocalibration methodologies to provide reliable densitometry measurements in heterogeneous acquisition protocols. METHODS We propose to reduce the effects of spatially variant noise such as nonuniform patterns of noise and biases. The method combines the statistical characterization of the signal-to-noise relationship in the CT image intensities, which allows us to estimate both the signal and spatially variant variance of noise, with an autocalibration technique that reduces the nonuniform biases caused by noise and reconstruction techniques. The method is firstly validated with anthropomorphic synthetic images that simulate CT acquisitions with variable scanning parameters: different dosage, nonhomogeneous variance of noise, and various reconstruction methods. We finally evaluate these effects and the ability of our method to provide consistent densitometric measurements in a cohort of clinical chest CT scans from two vendors (Siemens, n = 54 subjects; and GE, n = 50 subjects) acquired with several reconstruction algorithms (filtered back-projection and iterative reconstructions) with high-dose and low-dose protocols. RESULTS The harmonization reduces the effect of nonhomogeneous noise without compromising the resolution of the images (25% RMSE reduction in both clinical datasets). An analysis through hierarchical linear models showed that the average biases induced by differences in dosage and reconstruction methods are also reduced up to 74.20%, enabling comparable results between high-dose and low-dose reconstructions. We also assessed the statistical similarity between acquisitions obtaining increases of up to 30% points and showing that the low-dose vs high-dose comparisons of harmonized data obtain similar and even higher similarity than the observed for high-dose vs high-dose comparisons of nonharmonized data. CONCLUSION The proposed harmonization technique allows to compare measures of low-dose with high-dose acquisitions without using a specific reconstruction as a reference. Since the harmonization does not require a precalibration with a phantom, it can be applied to retrospective studies. This approach might be suitable for multicenter trials for which a reference reconstruction is not feasible or hard to define due to differences in vendors, models, and reconstruction techniques.
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Affiliation(s)
| | - Maria Jesus Ledesma-Carbayo
- Biomedical Image Technologies Laboratory (BIT) ETSI Telecomunicacion, UPM, and CIBER-BBN, Universidad Politécnica de Madrid, Madrid, Spain
| | - George R Washko
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Raúl San José Estépar
- Applied Chest Imaging Laboratory (ACIL), Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Ronit A, Kristensen T, Çolak Y, Kühl JT, Kalhauge A, Lange P, Nordestgaard BG, Vestbo J, Nielsen SD, Kofoed KF. Validation of lung density indices by cardiac CT for quantification of lung emphysema. Int J Chron Obstruct Pulmon Dis 2018; 13:3321-3330. [PMID: 30349236 PMCID: PMC6188118 DOI: 10.2147/copd.s172695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Objectives Cardiovascular disease is often associated with COPD. Lung density quantification of images obtained from cardiac computed tomography (CT) scans would allow simultaneous evaluation of emphysema and coronary artery calcification score and provide further mechanistic insight into the relationship between these syndromes. Patients and methods We assessed the agreement between lung density indices obtained by cardiac and full-lung CT scans. Paired cardiac and chest CT scans were assessed in 156 individuals with and without airflow limitation. Quantitative threshold indices of low attenuation area (LAA) and 15th percentile density index (PD15) were compared in terms of precision using Spearman’s correlation coefficient, accuracy using concordance correlation coefficient (CCC), and relative accuracy using P15 and P30. We also assessed the relationship between visually and quantitatively determined emphysema and used receiver operating characteristic curves to evaluate the ability of lung density indices to discriminate airflow limitation. Results Correlation coefficients between lung density indices obtained from cardiac and chest CT scans were 0.49 for percent LAA (%LAA)-950 and 0.71 for PD15. Corresponding values for CCC, P15, and P30 were 0.33, 3.2, and 5.1, respectively, for %LAA-950, and 0.34, 17.3, and 37.8, respectively, for PD15. For both cardiac and chest CT scans, visually determined emphysema was associated with higher %LAA-950 and lower PD15, and the ability of %LAA-950 and PD15 to discriminate airflow limitation were comparable. Conclusion Although chest CT imaging is preferable, cardiac CT imaging may also be used for lung emphysema quantification where association measures are of primary interest.
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Affiliation(s)
- Andreas Ronit
- Department of Infectious Diseases 8632, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark,
| | - Thomas Kristensen
- Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Yunus Çolak
- Department of Clinical Biochemistry and the Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark
| | - Jørgen Tobias Kühl
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Anna Kalhauge
- Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Lange
- Department of Public Health, Section of Social Medicine, University of Copenhagen, Copenhagen, Denmark.,Medical Unit, Respiratory Section, Hvidovre Hospital, Copenhagen University Hospital, Hvidovre, Denmark
| | - Børge G Nordestgaard
- Department of Clinical Biochemistry and the Copenhagen General Population Study, Herlev and Gentofte Hospital, Copenhagen University Hospital, Herlev, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Vestbo
- Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester, UK
| | - Susanne D Nielsen
- Department of Infectious Diseases 8632, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark,
| | - Klaus F Kofoed
- Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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11
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Abstract
Alpha-1-antitrypsin deficiency (AATD) is one of the most frequent genetic causes of liver and lung diseases. Despite its known association with chronic obstructive pulmonary disease (COPD), AATD is largely unrecognised and underdiagnosed. Cases of AATD exist within every COPD or spirometry population but must be actively investigated. AATD is a laboratory diagnosis that must be confirmed by a blood test. A number of clinical 'clues' can raise suspicion of AATD, potentially facilitating earlier diagnosis and initiation of appropriate treatment. Alpha-1-antitrypsin augmentation therapy has a clear role in patients with severe AATD and a FEV1 ≤65% predicted. Emerging evidence suggests that attenuating the decline in lung density may prolong the time to respiratory failure.
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Affiliation(s)
- Timm Greulich
- a Department of Medicine , Pulmonary and Critical Care Medicine, University Medical Center Giessen and Marburg , Marburg , Germany
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12
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Muramatsu S, Moriya H, Tsukagoshi S, Yamada N. [Development of Audio Indicator System for Respiratory Dynamic CT Imaging]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2018; 74:154-160. [PMID: 29459542 DOI: 10.6009/jjrt.2018_jsrt_74.2.154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We created the device, which can conduct a radiological technologist's voice to a subject during CT scanning. For 149 lung cancer, dynamic respiratory CT were performed. 92 cases were performed using this device, the others were without this device. The respiratory cycle and respiratory amplitude were analyzed from the lung density. A stable respirating cycle was obtained by using the audio indicator system. The audio indicator system is useful for respiratory dynamic CT.
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Affiliation(s)
- Shun Muramatsu
- Diagnostic Imaging Center, General Foundation Ohara Memorial Foundation
| | - Hiroshi Moriya
- Diagnostic Imaging Center, General Foundation Ohara Memorial Foundation
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13
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Diaz AA, Strand M, Coxson HO, Ross JC, San Jose Estepar R, Lynch D, van Rikxoort EM, Rosas IO, Hunninghake GM, Putman RK, Hatabu H, Yen A, Kinney GL, Hokanson JE, Silverman EK, Crapo J, Washko GR. Disease Severity Dependence of the Longitudinal Association Between CT Lung Density and Lung Function in Smokers. Chest 2018; 153:638-45. [PMID: 29066389 DOI: 10.1016/j.chest.2017.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 08/04/2017] [Accepted: 10/02/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND In smokers, the lung parenchyma is characterized by inflammation and emphysema, processes that can result in local gain and loss of lung tissue. CT measures of lung density might reflect lung tissue changes; however, longitudinal data regarding the effects of CT lung tissue on FEV1 in smokers with and without COPD are scarce. METHODS The 15th percentile of CT lung density was obtained from the scans of 3,390 smokers who completed baseline and 5-year follow-up of the Genetic Epidemiology of COPD (COPDGene) study visits. The longitudinal relationship between total lung capacity-adjusted lung density (TLC-PD15) and FEV1 was assessed by using multivariable mixed models. Separate models were performed in smokers at risk, smokers with preserved ratio and impaired spirometry (PRISm), and smokers with COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging system. RESULTS The direction of the relationship between lung density and lung function was GOLD stage dependent. In smokers with PRISm, a 1-g/L decrease in TLC-PD15 was associated with an increase of 2.8 mL FEV1 (P = .02). In contrast, among smokers with GOLD III to IV COPD, a 1-g/L decrease in TLC-PD15 was associated with a decrease of 4.1 mL FEV1 (P = .002). CONCLUSIONS A decline in TLC-PD15 was associated with an increase or decrease in FEV1 depending on disease severity. The associations are GOLD stage specific, and their presence might influence the interpretation of future studies that use CT lung density as an intermediate study end point for a decline in lung function. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.
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14
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Rodriguez A, Ranallo FN, Judy PF, Fain SB. The effects of iterative reconstruction and kernel selection on quantitative computed tomography measures of lung density. Med Phys 2017; 44:2267-2280. [PMID: 28376262 DOI: 10.1002/mp.12255] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/23/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To determine the effects of iterative reconstruction (IR) and high-frequency kernels on quantitative computed tomography (qCT) density measures at reduced X-ray dose. MATERIALS AND METHODS The COPDGene 2 Phantom (CTP 698, The Phantom Laboratory, Salem, NY) with four embedded lung mimicking foam densities (12lb, 20lb, and 4lb), as well as water, air, and acrylic reference inserts, was imaged using a GE 64 slice CT750 HD scanner in helical mode with four current-time products ranging from 12 to 100 mAs. The raw acquired data were reconstructed using standard (STD - low frequency) and Bone (high frequency) kernels with filtered back projection (FBP), 100% ASiR, and Veo reconstruction algorithms. The reference density inserts were manually segmented using Slicer3D (www.slicer.org), and the mean, standard deviation, and histograms of the segmented regions were generated using Fiji (http://fiji.sc/Fiji) for each reconstruction. Measurements of threshold values placed on the cumulative frequency distribution of voxels determined by these measured histograms at 5%, PD5phant , and 15%, PD15phant , (analogous to the relative area below -950 HU (RA-950) and percent density 15 (PD15) in human lung emphysema quantification, respectively), were also performed. RESULTS The use of high-resolution kernels in conjunction with ASiR and Veo did not significantly affect the mean Hounsfield units (HU) of each of the density standards (< 4 HU deviation) and current-time products within the phantom when compared with the STD+FBP reconstruction conventionally used in clinical applications. A truncation of the scanner reported HU values at -1024 that shifts the mean toward more positive values was found to cause a systematic error in lower attenuating regions. Use of IR drove convergence toward the mean of measured histograms (~100-137% increase in the number measured voxels at the mean of the histogram), while the combination of Bone+ASiR preserved the standard deviation of HU values about the mean compared to STD+FBP, with the added effect of improved spatial resolution and accuracy in airway measures. PD5phant and PD15phant were most similar between the Bone+ASiR and STD+FBP in all regions except those affected by the -1024 truncation artifact. CONCLUSIONS Extension of the scanner reportable HU values below the present limit of -1024 will mitigate discrepancies found in qCT lung densitometry in low-density regions. The density histogram became more sharply peaked, and standard deviation was reduced for IR, directly effecting density thresholds, PD5phant and PD15phant, placed on the cumulative frequency distribution of each region in the phantom, which serve as analogs to RA-950 and PD15 typically used in lung density quantitation. The combination of high-frequency kernels (Bone) with ASiR mitigates this effect and preserves density measures derived from the image histogram. Moreover, previous studies have shown improved accuracy of qCT airway measures of wall thickness (WT) and wall area percentage (WA%) when using high-frequency kernels in combination with ASiR to better represent airway walls. The results therefore suggest an IR approach for accurate assessment of airway and parenchymal density measures in the lungs.
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Affiliation(s)
- Alfonso Rodriguez
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Frank N Ranallo
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | | | - Sean B Fain
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Department of Biomedical Engineering, University of Wisconsin School of Engineering, Madison, WI, USA
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15
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Ma S, Lin YY, Cantor JO, Chapman KR, Sandhaus RA, Fries M, Edelman JM, McElvaney G, Turino GM. The Effect of Alpha-1 Proteinase Inhibitor on Biomarkers of Elastin Degradation in Alpha-1 Antitrypsin Deficiency: An Analysis of the RAPID/RAPID Extension Trials. Chronic Obstr Pulm Dis 2016; 4:34-44. [PMID: 28848909 DOI: 10.15326/jcopdf.4.1.2016.0156] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The RAPID (NCT00261833; N=180) and RAPID Extension (NCT00670007; N=140) trials demonstrated significantly reduced lung density decline in patients with alpha-1 antitrypsin deficiency (AATD) receiving alpha-1 proteinase inhibitor (A1PI) versus placebo. Desmosine and isodesmosine (DES/IDES) are unique crosslinkers of mature elastin fibers and are utilized as measures of elastin degradation. The aim of this post-hoc study was to determine the effect of A1PI therapy on DES/IDES levels in patients from RAPID/RAPID Extension. Plasma levels of DES/IDES were measured using high-performance liquid chromatography and tandem mass spectrometry. Correlation between changes in DES/IDES levels and computed tomography (CT) lung density decline was assessed. Analysis showed that DES/IDES levels were significantly reduced versus baseline in patients receiving A1PI at all time points, from month 3 through month 48. A significant increase from baseline in DES/IDES was observed with placebo at month 24 (n=54; 0.016; p=0.018). DES/IDES change from baseline was significantly different with A1PI versus placebo at months 3 (-0.021; 95% confidence interval [CI] -0.037, 0.004; p=0.026), 12 (-0.040; 95% CI -0.055, 0.025; p<0.001), and 24 (-0.052; 95% CI -0.070, 0.034; p<0.001). Placebo patients started A1PI therapy at month 24 and showed significant reductions in plasma DES/IDES at months 36 (p<0.001) and 48 (p<0.001). Reduced elastin degradation was associated with slower lung density decline (p=0.005), correlating a chemical index of therapy with an anatomical index by CT. In conclusion, A1PI therapy reduced elastin degradation, including pulmonary elastin, in patients with AATD. These data support using DES/IDES levels as biomarkers to monitor emphysema progression and treatment response.
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Affiliation(s)
- Shuren Ma
- James P. Mara Center for Lung Disease at Mt. Sinai, Department of Medicine, St. Luke's-Roosevelt Hospital, New York, New York
| | - Yong Y Lin
- James P. Mara Center for Lung Disease at Mt. Sinai, Department of Medicine, St. Luke's-Roosevelt Hospital, New York, New York
| | - Jerome O Cantor
- James P. Mara Center for Lung Disease at Mt. Sinai, Department of Medicine, St. Luke's-Roosevelt Hospital, New York, New York
| | - Kenneth R Chapman
- Asthma and Airway Centre, University Health Network, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Robert A Sandhaus
- Division of Pulmonary, Critical Care and Sleep Medicine, National Jewish Health, Denver, Colorado
| | - Michael Fries
- Clinical Strategy and Development, CSL Behring, King of Prussia, Pennsylvania
| | - Jonathan M Edelman
- Clinical Strategy and Development, CSL Behring, King of Prussia, Pennsylvania
| | - Gerard McElvaney
- Department of Respiratory Medicine, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gerard M Turino
- James P. Mara Center for Lung Disease at Mt. Sinai, Department of Medicine, St. Luke's-Roosevelt Hospital, New York, New York
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16
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Camiciottoli G, Diciotti S, Bigazzi F, Lombardo S, Bartolucci M, Paoletti M, Mascalchi M, Pistolesi M. Is intrathoracic tracheal collapsibility correlated to clinical phenotypes and sex in patients with COPD? Int J Chron Obstruct Pulmon Dis 2015; 10:843-52. [PMID: 25960647 PMCID: PMC4423505 DOI: 10.2147/copd.s80558] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A substantial proportion of patients with chronic obstructive pulmonary disease (COPD) develops various degree of intrathoracic tracheal collapsibility. We studied whether the magnitude of intrathoracic tracheal collapsibility could be different across clinical phenotypes and sex in COPD. Intrathoracic tracheal collapsibility measured at paired inspiratory-expiratory low dose computed tomography (CT) and its correlation with clinical, functional, and CT-densitometric data were investigated in 69 patients with COPD according to their predominant conductive airway or emphysema phenotypes and according to sex. Intrathoracic tracheal collapsibility was higher in patients with predominant conductive airway disease (n=28) and in females (n=27). Women with a predominant conductive airway phenotype (n=10) showed a significantly greater degree of collapsibility than women with predominant emphysema (28.9%±4% versus 11.6%±2%; P<0.001). Intrathoracic tracheal collapsibility was directly correlated with inspiratory-expiratory volume variation at CT and with forced expiratory volume (1 second), and inversely correlated with reduced CT lung density and functional residual capacity. Intrathoracic tracheal collapsibility was not correlated with cough and wheezing; however, intrathoracic tracheal collapsibility and clinical phenotypes of COPD are closely correlated. In patients with a predominant emphysematous phenotype, a reduced collapsibility may reflect the mechanical properties of the stiff hyperinflated emphysematous lung. The high collapsibility in patients with predominant airway disease, mild airway obstruction, and in women with this phenotype may reflect chronic airway inflammation. The lack of relationship with such symptoms as wheezing, cough, and dyspnea could indicate that intrathoracic tracheal collapsibility itself should be considered neither an abnormal feature of COPD nor a relevant clinical finding.
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Affiliation(s)
- Gianna Camiciottoli
- Section of Respiratory Medicine, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | - Stefano Diciotti
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi," University of Bologna, Cesena, Italy
| | - Francesca Bigazzi
- Section of Respiratory Medicine, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | - Simone Lombardo
- Radiodiagnostic Section, Department of Clinical and Experimental Biomedical Sciences, University of Florence, Florence, Italy
| | - Maurizio Bartolucci
- Department of Diagnostic Imaging, Careggi University Hospital, Florence, Italy
| | - Matteo Paoletti
- Section of Respiratory Medicine, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
| | - Mario Mascalchi
- Radiodiagnostic Section, Department of Clinical and Experimental Biomedical Sciences, University of Florence, Florence, Italy
| | - Massimo Pistolesi
- Section of Respiratory Medicine, Department of Clinical and Experimental Medicine, University of Florence, Florence, Italy
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17
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Detombe SA, Dunmore-Buyze J, Petrov IE, Drangova M. X-ray dose delivered during a longitudinal micro-CT study has no adverse effect on cardiac and pulmonary tissue in C57BL/6 mice. Acta Radiol 2013; 54:435-41. [PMID: 23436828 DOI: 10.1177/0284185113475608] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Micro-computed tomography (micro-CT) offers numerous advantages for small animal imaging, including the ability to monitor the same animals throughout a longitudinal study. However, concerns are often raised regarding the effects of X-ray dose accumulated over the course of the experiment. PURPOSE To scan C57BL/6 mice multiple times per week for 6 weeks, in order to determine the effect of the cumulative dose on pulmonary and cardiac tissue at the end of the study. MATERIAL AND METHODS C57BL/6 male mice were split into two groups (irradiated group = 10, control group = 10). The irradiated group was scanned (80 kVp/50 mA) three times weekly for 6 weeks, resulting in a weekly dose of 0.84 Gy, and a total study dose of 5.04 Gy. The control group was scanned on the final week. Scans from week 6 were reconstructed and the lungs and heart were analyzed. RESULTS Overall, there was no significant difference in lung volume or lung density or in left ventricular volume or ejection fraction between the control group and the irradiated group. Histological samples taken from excised lung and myocardial tissue also showed no evidence of inflammation or fibrosis in the irradiated group. CONCLUSION This study demonstrated that a 5 Gy X-ray dose accumulated over 6 weeks during a longitudinal micro-CT study had no significant effects on the pulmonary and myocardial tissue of C57BL/6 mice. As a result, the many advantages of micro-CT imaging, including rapid acquisition of high-resolution, isotropic images in free-breathing mice, can be taken advantage of in longitudinal studies without concern for negative dose-related effects.
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Affiliation(s)
- Sarah A Detombe
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, ON
- Department of Medical Biophysics, Western University, London, ON, Canada
| | - Joy Dunmore-Buyze
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, ON
| | - Ivailo E Petrov
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, ON
| | - Maria Drangova
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, ON
- Department of Medical Biophysics, Western University, London, ON, Canada
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18
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Moloney F, McWilliams S, Crush L, Laughlin PDM, Kenneddy M, Henry M, O' Connor O, Maher MM. CT Densitometry as a Predictor of Pulmonary Function in Lung Cancer Patients. Open Respir Med J 2012; 6:139-44. [PMID: 23264834 PMCID: PMC3527876 DOI: 10.2174/1874306401206010139] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/16/2012] [Accepted: 11/14/2012] [Indexed: 12/03/2022] Open
Abstract
Purpose: Preoperative pulmonary assessment is undertaken in patients with resectable lung cancer to identify
those at increased risk of perioperative complications. Guidelines from the American College of Chest Physicians indicate
that if the FEV1 and DLCO are ≥60% of predicted, patients are suitable for resection without further evaluation.
The aim of our study is to determine if quantitative measures of lung volume and density obtained from pre-operative CT
scans correlate with pulmonary function tests. This may allow us to predict pulmonary function in patients with lung
cancer and identify patients who would tolerate surgical resection.
Materials and Methods: Patients were identified retrospectively from the lung cancer database of a tertiary hospital. Image
segmentation software was utilized to estimate total lung volume, normal lung volume (values -500 HU to -910 HU),
emphysematous volume (values less than -910 HU), and mean lung density from pre-operative CT studies for each patient
and these values were compared to contemporaneous pulmonary function tests.
Results: A total of 77 patients were enrolled. FEV1 was found to correlate significantly with the mean lung density
(r=.762, p<.001) and the volume of emphysema (r= -.678, p<.001). DLCO correlated significantly with the mean lung
density (r =.648, p<.001) and the volume of emphysematous lung (r= -.535, p<.001).
Conclusion: The results of this study suggest that both FEV1 and DLCO correlate significantly with volume of
emphysema and mean lung density. We now plan to prospectively compare these CT parameters with measures of good
and poor outcome postoperatively to identify CT measures that may predict surgical outcome preoperatively
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Affiliation(s)
- Fiachra Moloney
- Department of Radiology, Cork University Hospital and University College Cork, Cork, Ireland
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19
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Vijayasaratha K, Stockley RA. Relationship between frequency, length, and treatment outcome of exacerbations to baseline lung function and lung density in alpha-1 antitrypsin-deficient COPD. Int J Chron Obstruct Pulmon Dis 2012; 7:789-96. [PMID: 23226015 PMCID: PMC3514009 DOI: 10.2147/copd.s31797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background Diary cards are useful for analyzing exacerbations in chronic obstructive pulmonary disease (COPD), although factors influencing the length and frequency of each episode are poorly understood. This study investigated factors that influence the features of exacerbations in patients with alpha-1 antitrypsin (AAT) deficiency (PiZ phenotype) and COPD. Methods Daily diary cards were collected over 2 years. Patients had emphysema visualized and quantified by computed tomography scan, and had at least one documented exacerbation in the previous year. Results The patients (n = 23) had a mean age of 52.5 years, forced expiratory volume in one second (FEV1) of 1.2 L (38.4% predicted), corrected gas transfer (KCO) of 0.90 mmol/min/kPa/L (59.7% predicted), and 15th percentile lung density of 44.55 g/L. Two hundred and sixty-three exacerbations (164 treated) were identified. The frequency of treated exacerbations correlated negatively with KCO% predicted (r = −0.432; P = 0.022). Exacerbation length (determined for 17 of the patients for whom diary card data through the episode were available) correlated negatively with baseline 15th percentile lung density (r = −0.361; P = 0.003), and increased the longer treatment was delayed (r = 0.503; P < 0.001). Treatment delay was shorter with higher day 1 symptom score, lower baseline FEV1, FEV1/forced vital capacity, and lower 15th percentile lung density (r = −0.368, 0.272, 0.461, and 0.786; P = 0.004, 0.036, <0.001, and <0.001, respectively). Time to resolution of exacerbation after treatment initiation was not affected by treatment delay, but correlated negatively with KCO% predicted (r = −0.647; P = 0.007). Conclusion In alpha-1 antitrypsin deficiency, the frequency and length of resolution of exacerbation were related to baseline gas transfer. Treatment delay adversely affected exacerbation length, and lung density was the best independent predictor of delay in starting treatment.
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Wang L, Yorke E, Desobry G, Chui CS. Dosimetric advantage of using 6 MV over 15 MV photons in conformal therapy of lung cancer: Monte Carlo studies in patient geometries. J Appl Clin Med Phys 2002; 3:51-9. [PMID: 11818004 PMCID: PMC5724543 DOI: 10.1120/jacmp.v3i1.2592] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2001] [Accepted: 10/26/2001] [Indexed: 11/28/2022] Open
Abstract
Many lung cancer patients who undergo radiation therapy are treated with higher energy photons (15-18 MV) to obtain deeper penetration and better dose uniformity. However, the longer range of the higher energy recoil electrons in the low-density medium may cause lateral electronic disequilibrium and degrade the target coverage. To compare the dose homogeneity achieved with lower versus higher energy photon beams, we performed a dosimetric study of 6 and 15 MV three-dimensional (3D) conformal treatment plans for lung cancer using an accurate, patient-specific dose-calculation method based on a Monte Carlo technique. A 6 and 15 MV 3D conformal treatment plan was generated for each of two patients with target volumes exceeding 200 cm(3) on an in-house treatment planning system in routine clinical use. Each plan employed four conformally shaped photon beams. Each dose distribution was recalculated with the Monte Carlo method, utilizing the same beam geometry and patient-specific computed tomography (CT) images. Treatment plans using the two energies were compared in terms of their isodose distributions and dose-volume histograms (DVHs). The 15 MV dose distributions and DVHs generated by the clinical treatment planning calculations were as good as, or slightly better than, those generated for 6 MV beams. However, the Monte Carlo dose calculation predicted increased penumbra width with increased photon energy resulting in decreased lateral dose homogeneity for the 15 MV plans. Monte Carlo calculations showed that all target coverage indicators were significantly worse for 15 MV than for 6 MV; particularly the portion of the planning target volume (PTV) receiving at least 95% of the prescription dose (V(95)) dropped dramatically for the 15 MV plan in comparison to the 6 MV. Spinal cord and lung doses were clinically equivalent for the two energies. In treatment planning of tumors that abut lung tissue, lower energy (6 MV) photon beams should be preferred over higher energies (15-18 MV) because of the significant loss of lateral dose equilibrium for high-energy beams in the low-density medium. Any gains in radial dose uniformity across steep density gradients for higher energy beams must be weighed carefully against the lateral beam degradation due to penumbra widening.
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Affiliation(s)
- Lu Wang
- Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
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