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Burrowes KS, De Backer J, Kumar H. Image-based computational fluid dynamics in the lung: virtual reality or new clinical practice? Wiley Interdiscip Rev Syst Biol Med 2017; 9. [PMID: 28608962 DOI: 10.1002/wsbm.1392] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/12/2017] [Accepted: 04/19/2017] [Indexed: 11/05/2022]
Abstract
The development and implementation of personalized medicine is paramount to improving the efficiency and efficacy of patient care. In the respiratory system, function is largely dictated by the choreographed movement of air and blood to the gas exchange surface. The passage of air begins in the upper airways, either via the mouth or nose, and terminates at the alveolar interface, while blood flows from the heart to the alveoli and back again. Computational fluid dynamics (CFD) is a well-established tool for predicting fluid flows and pressure distributions within complex systems. Traditionally CFD has been used to aid in the effective or improved design of a system or device; however, it has become increasingly exploited in biological and medical-based applications further broadening the scope of this computational technique. In this review, we discuss the advancement in application of CFD to the respiratory system and the contributions CFD is currently making toward improving precision medicine. The key areas CFD has been applied to in the pulmonary system are in predicting fluid transport and aerosol distribution within the airways. Here we focus our discussion on fluid flows and in particular on image-based clinically focused CFD in the ventilatory system. We discuss studies spanning from the paranasal sinuses through the conducting airways down to the level of the alveolar airways. The combination of imaging and CFD is enabling improved device design in aerosol transport, improved biomarkers of lung function in clinical trials, and improved predictions and assessment of surgical interventions in the nasal sinuses. WIREs Syst Biol Med 2017, 9:e1392. doi: 10.1002/wsbm.1392 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Kelly S Burrowes
- Department of Chemical and Materials Engineering, University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | | | - Haribalan Kumar
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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Stahr CS, Samarage CR, Donnelley M, Farrow N, Morgan KS, Zosky G, Boucher RC, Siu KKW, Mall MA, Parsons DW, Dubsky S, Fouras A. Quantification of heterogeneity in lung disease with image-based pulmonary function testing. Sci Rep 2016; 6:29438. [PMID: 27461961 PMCID: PMC4962033 DOI: 10.1038/srep29438] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/17/2016] [Indexed: 12/15/2022] Open
Abstract
Computed tomography (CT) and spirometry are the mainstays of clinical pulmonary assessment. Spirometry is effort dependent and only provides a single global measure that is insensitive for regional disease, and as such, poor for capturing the early onset of lung disease, especially patchy disease such as cystic fibrosis lung disease. CT sensitively measures change in structure associated with advanced lung disease. However, obstructions in the peripheral airways and early onset of lung stiffening are often difficult to detect. Furthermore, CT imaging poses a radiation risk, particularly for young children, and dose reduction tends to result in reduced resolution. Here, we apply a series of lung tissue motion analyses, to achieve regional pulmonary function assessment in β-ENaC-overexpressing mice, a well-established model of lung disease. The expiratory time constants of regional airflows in the segmented airway tree were quantified as a measure of regional lung function. Our results showed marked heterogeneous lung function in β-ENaC-Tg mice compared to wild-type littermate controls; identified locations of airway obstruction, and quantified regions of bimodal airway resistance demonstrating lung compensation. These results demonstrate the applicability of regional lung function derived from lung motion as an effective alternative respiratory diagnostic tool.
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Affiliation(s)
- Charlene S Stahr
- Department of Mechanical &Aerospace Engineering, Monash University, Melbourne, VIC, Australia
| | | | - Martin Donnelley
- Robinson Research Institute, University of Adelaide, SA, Australia.,Women's and Children's Hospital, North Adelaide, SA, Australia
| | - Nigel Farrow
- Robinson Research Institute, University of Adelaide, SA, Australia.,Women's and Children's Hospital, North Adelaide, SA, Australia
| | - Kaye S Morgan
- School of Physics and Astronomy, Monash University, Melbourne, VIC, Australia
| | - Graeme Zosky
- School of Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Richard C Boucher
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Karen K W Siu
- School of Physics and Astronomy, Monash University, Melbourne, VIC, Australia
| | - Marcus A Mall
- Department of Translational Pulmonology Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - David W Parsons
- Robinson Research Institute, University of Adelaide, SA, Australia.,Women's and Children's Hospital, North Adelaide, SA, Australia
| | - Stephen Dubsky
- Department of Mechanical &Aerospace Engineering, Monash University, Melbourne, VIC, Australia.,4Dx Limited, Melbourne, VIC, Australia
| | - Andreas Fouras
- Department of Mechanical &Aerospace Engineering, Monash University, Melbourne, VIC, Australia.,4Dx Limited, Melbourne, VIC, Australia
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Kim HG, Shin HJ, Kim YH, Sohn MH, Lyu CJ, Kim M, Kim KW, Lee M. Quantitative computed tomography assessment of graft-versus-host disease-related bronchiolitis obliterans in children: A pilot feasibility study. Eur Radiol 2015; 25:2931-6. [DOI: 10.1007/s00330-015-3700-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/24/2015] [Accepted: 03/02/2015] [Indexed: 10/23/2022]
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Owsijewitsch M, Ley-Zaporozhan J, Kuhnigk JM, Kopp-Schneider A, Eberhardt R, Eichinger M, Heussel CP, Kauczor HU, Ley S. Quantitative Emphysema Distribution in Anatomic and Non-anatomic Lung Regions. COPD 2014; 12:257-66. [PMID: 25230093 DOI: 10.3109/15412555.2014.933950] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [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: 12/24/2022]
Abstract
PURPOSE The change of emphysema distribution with increasing COPD severity is not yet assessed. Especially, involvement of the upper aspect of the lower lobe is unknown. The primary aim was to quantitatively determine regional distribution of emphysema in anatomically (lung lobes) and non-anatomically defined lung regions (upper/lower lung halves as well as core and rind regions) in a cohort covering equally all COPD severity stages using CT. MATERIAL AND METHODS Basically 100 CT data sets were quantitatively evaluated for regional distribution of emphysema. Emphysema characteristics (emphysema index, mean lung density and 15th percentile of the attenuation values of lung voxels) were compared (t-test) in: upper lobes vs. upper halves, lower lobes vs. lower halves, core vs. rind region. RESULTS In patients with ≤ GOLD II, a significantly higher emphysema burden was found in the upper lobes as compared to upper halves. In subjects with GOLD III/IV the differences were not significant for all emphysema characteristics. A high difference between lobes and halves in subjects with ≤ GOLD II was found, in contrast to low difference in higher GOLD stages. CONCLUSIONS Lobar segmentation provides improved characterization of cranio-caudal emphysema distribution compared to a non-anatomic approach in subjects up to GOLD stage II.
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Affiliation(s)
- Michael Owsijewitsch
- 1Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg , Heidelberg , Germany
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Yamada Y, Jinzaki M, Hashimoto M, Shiomi E, Abe T, Kuribayashi S, Ogawa K. Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference. Eur Radiol 2013; 23:2118-26. [DOI: 10.1007/s00330-013-2814-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Revised: 01/25/2013] [Accepted: 02/09/2013] [Indexed: 10/27/2022]
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Li Y, Swensen SJ, Karabekmez LG, Marks RS, Stoddard SM, Jiang R, Worra JB, Zhang F, Midthun DE, de Andrade M, Song Y, Yang P. Effect of emphysema on lung cancer risk in smokers: a computed tomography-based assessment. Cancer Prev Res (Phila) 2010; 4:43-50. [PMID: 21119049 DOI: 10.1158/1940-6207.capr-10-0151] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The contribution of emphysema to lung cancer risk has been recognized, but the effect size needs to be further defined. In this study, 565 primary lung cancer cases were enrolled though a prospective lung cancer cohort at Mayo Clinic, and 450 controls were smokers participating in a lung cancer screening study in the same institution using spiral computed tomography (CT). Cases and controls were frequency matched on age, gender, race, smoking status, and residential region. CT imaging using standard protocol at the time of lung cancer diagnosis (case) or during the study (control) was assessed for emphysema by visual scoring CT analysis as a percentage of lung tissue destroyed. The clinical definition of emphysema was the diagnosis recorded in the medical documentation. Using multiple logistic regression models, emphysema (≥ 5% on CT) was found to be associated with a 3.8-fold increased lung cancer risk in Caucasians, with higher risk in subgroups of younger (<65 years old, OR = 4.64), heavy smokers (≥ 40 pack-years, OR = 4.46), and small-cell lung cancer (OR = 5.62). When using >0% or ≥ 10% emphysema on CT, lung cancer risk was 2.79-fold or 3.33-fold higher than controls. Compared with CT evaluation (using criterion ≥ 5%), the sensitivity, specificity, positive and negative predictive values, and the accuracy of the clinical diagnosis for emphysema in controls were 19%, 98%, 73%, 84%, and 83%, respectively. These results imply that an accurate evaluation of emphysema could help reliably identify individuals at greater risk of lung cancer among smokers.
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Affiliation(s)
- Yan Li
- Department of Respiratory Medicine, Jinling Hospital, Nanjing University School of Medicine, Nanjing, PR China
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Bastarrika G, Wisnivesky JP, Pueyo JC, Díaz L, Arraiza M, Villanueva A, Alcaide AB, Campo A, Seijo L, de Torres JP, Zulueta JJ. Low-dose volumetric computed tomography for quantification of emphysema in asymptomatic smokers participating in an early lung cancer detection trial. J Thorac Imaging 2009; 24:206-11. [PMID: 19704324 DOI: 10.1097/RTI.0b013e3181a65263] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE High-resolution computed tomography (CT) is a validated method to quantify the extent of pulmonary emphysema. In this study, we assessed the reliability of low-dose volumetric CT (LDCT) for the quantification of emphysema and its correlation with spirometric indices of airway obstruction. MATERIALS AND METHODS The study population consisted of 102 consecutive current and former smokers participating in a lung cancer screening trial. All subjects underwent spirometry testing and LDCT at entry and a LDCT after 12 months. The extent of emphysema was estimated by 2 techniques; by using the lung attenuation threshold analysis and by visual assessment of the 2 independent radiologists. The reproducibility of these determinations was assessed using test-retest reliability and kappa coefficient of agreement. The correlation of LDCT-based emphysema determinations with indices of airway obstruction on spirometry was also calculated. RESULTS Eighty percent of the participants were male, with a mean (standard deviation) age of 54.5 (7.5) years, and median pack-years (interquartile range) of 20 (24). Test-retest reliability of all LDCT-based emphysema determinations was very good (intraclass correlation coefficient of 0.92 for the volume of emphysema, and 0.93 for the emphysema index or emphysema volume/total lung volume). Similarly, there was an excellent interrater agreement for visual assessment of emphysema (kappa coefficient=0.91). Higher volumes of emphysema measured quantitatively or visually significantly correlated with spirometric markers of airway obstruction. CONCLUSIONS Volumetric LDCT is a reliable and valid technique for the quantification of emphysema in asymptomatic smokers.
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Abstract
We aim at improving quantitative measures of emphysema in computed tomography (CT) images of the lungs. Current standard measures, such as the relative area of emphysema (RA), rely on a single intensity threshold on individual pixels, thus ignoring any interrelations between pixels. Texture analysis allows for a much richer representation that also takes the local structure around pixels into account. This paper presents a texture classification-based system for emphysema quantification in CT images. Measures of emphysema severity are obtained by fusing pixel posterior probabilities output by a classifier. Local binary patterns (LBP) are used as texture features, and joint LBP and intensity histograms are used for characterizing regions of interest (ROIs). Classification is then performed using a k nearest neighbor classifier with a histogram dissimilarity measure as distance. A 95.2% classification accuracy was achieved on a set of 168 manually annotated ROIs, comprising the three classes: normal tissue, centrilobular emphysema, and paraseptal emphysema. The measured emphysema severity was in good agreement with a pulmonary function test (PFT) achieving correlation coefficients of up to |r| = 0.79 in 39 subjects. The results were compared to RA and to a Gaussian filter bank, and the texture-based measures correlated significantly better with PFT than did RA.
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Affiliation(s)
- Lauge Sørensen
- Image Group, Department of Computer Science, University of Copenhagen, DK-2110 Copenhagen, Denmark.
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Yu J, Law M, Kadlecek S, Emami K, Ishii M, Stephen M, Woodburn JM, Vahdat V, Rizi RR. Simultaneous measurement of pulmonary partial pressure of oxygen and apparent diffusion coefficient by hyperpolarized 3He MRI. Magn Reson Med 2009; 61:1015-21. [PMID: 19230017 DOI: 10.1002/mrm.21854] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hyperpolarized (3)He (HP (3)He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional, and noninvasive way. Structural HP (3)He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease-induced lung microstructure changes at the alveolar level, and HP (3)He pulmonary partial pressure of oxygen (pO(2)) imaging measures the oxygen transfer efficiency between the lung and blood stream. Although both parameters are affected in chronic obstructive pulmonary disease (COPD), a quantitative assessment of the regional correlation of the two parameters has not been reported in the literature. In this work, a single acquisition technique for the simultaneous measurement of ADC and pO(2) is presented. This technique is based on the multiple regression method, in which a general linear estimator is used to retrieve the values of ADC and pO(2) from a series of measurements. The measurement uncertainties are also analytically derived and used to find an optimal measurement scheme. The technique was first tested on a phantom model, and then on an in vivo normal pig experiment. A case study was performed on a COPD patient, which showed that in a region of interest ADC was 29% higher while oxygen depletion rate was 61% lower than the corresponding global average values.
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Affiliation(s)
- Jiangsheng Yu
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Irion KL, Marchiori E, Hochhegger B, Porto Nda S, Moreira Jda S, Anselmi CE, Holemans JA, Irion PO. CT quantification of emphysema in young subjects with no recognizable chest disease. AJR Am J Roentgenol 2009; 192:W90-6. [PMID: 19234245 DOI: 10.2214/AJR.07.3502] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this prospective study was to evaluate volumetric CT emphysema quantification (CT densitovolumetry) in a young population with no recognizable lung disease. SUBJECTS AND METHODS A cohort of 30 nonsmoking patients with no recognizable lung disease (16 men, 14 women; age range, 19-41 years) underwent inspiratory and expiratory CT, after which the data were postprocessed for volumetric quantification of emphysema (threshold, -950 HU). Correlation was tested for age, weight, height, sex, body surface area (BSA), and physical activity. Normal limits were established by mean +/- 1.96 SD. RESULTS No correlation was found between the measured volumes and age or physical activity. Correlation was found between BSA and normal lung volume in inspiration (r = 0.69, p = 0.000), shrink volume (i.e., difference in total lung volume in inspiration and in expiration) (r = 0.66, p = 0.000), and percentage of shrink volume (r = 0.35, p = 0.05). For an alpha error of 5%, the limits of normality based on this sample are percentage of emphysema in inspiration, 0.35%; percentage of emphysema in expiration, 0.12%; and maximum lung volume in expiration, 3.6 L. The maximum predicted percentage of shrink volume can be calculated as %SV = 29.43% + 16.97% x BSA (+/- 1.96 x 7.61%). CONCLUSION Young healthy nonsmokers with no recognizable lung disease can also show a small proportion of emphysematous-like changes on CT densitovolumetry when a threshold of -950 HU is used. Reference values should be considered when applying the technique for early detection or grading of emphysema and when studying aging lungs.
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Litmanovich D, Boiselle PM, Bankier AA. CT of pulmonary emphysema - current status, challenges, and future directions. Eur Radiol 2009; 19:537-51. [DOI: 10.1007/s00330-008-1186-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2008] [Revised: 07/16/2008] [Accepted: 08/15/2008] [Indexed: 10/21/2022]
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Robbesom AA, Koenders MM, Smits NC, Hafmans T, Versteeg EM, Bulten J, Veerkamp JH, Dekhuijzen PN, van Kuppevelt TH. Aberrant fibrillin-1 expression in early emphysematous human lung: a proposed predisposition for emphysema. Mod Pathol 2008; 21:297-307. [PMID: 18084245 DOI: 10.1038/modpathol.3801004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Parenchymal destruction, airspace enlargement, and loss of elasticity are hallmarks of pulmonary emphysema. Although the basic mechanism is unknown, there is a consensus that malfunctioning of the extracellular matrix is a major contributor to the pathogenesis of emphysema. In this study, we analyzed the expression of the elastic fiber protein fibrillin-1 in a large number (n=69) of human lung specimens with early-onset emphysema. Specimens were morphologically characterized by the Destructive Index, the Mean Linear Intercept, and the Panel Grading. We observed a strong correlation (P<0.001) of aberrant fibrillin-1 staining with the degree of destruction of lung parenchyma (r=0.71), airspace enlargement (r=0.47), and emphysema-related morphological abnormalities (r=0.69). There were no obvious correlations with age and smoking behavior. Staining for three other extracellular matrix components (type I collagen, type IV collagen, and laminin) was not affected. The aberrant fibrillin-1 staining observed in this study is similar to that observed in Marfan syndrome, a syndrome caused by mutations in the gene encoding fibrillin-1. Strikingly, emphysema is noticed in a number of Marfan patients. This, together with the notion that disruption of the fibrillin-1 gene in mice results in emphysematous lesions, makes fibrillin-1 a strong candidate to be involved in the etiology and pathogenesis of emphysema.
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Irion KL, Hochhegger B, Marchiori E, Porto NDS, Baldisserotto SDV, Santana PR. Radiograma de tórax e tomografia computadorizada na avaliação do enfisema pulmonar. J Bras Pneumol 2007; 33:720-32. [DOI: 10.1590/s1806-37132007000600017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Accepted: 08/15/2008] [Indexed: 01/15/2023] Open
Abstract
O enfisema é uma condição do pulmão, caracterizada pelo aumento acima do normal no tamanho dos espaços aéreos distais ao bronquíolo terminal. Atualmente, o enfisema é a quarta causa de morte nos EUA, afetando 14 milhões de pessoas. O presente artigo descreve as principais ferramentas no diagnóstico por imagem do enfisema, desde o início até os dias de hoje. Relata as técnicas tradicionais, como radiograma de tórax, e as evoluções no campo da tomografia computadorizada (TC), como a TC de alta resolução e a densitovolumetria pulmonar por TC tridimensional.
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Ley-Zaporozhan J, Ley S, Eberhardt R, Weinheimer O, Fink C, Puderbach M, Eichinger M, Herth F, Kauczor HU. Assessment of the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level in patients with emphysema. Eur J Radiol 2007; 63:76-83. [PMID: 17320333 DOI: 10.1016/j.ejrad.2007.01.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Revised: 01/15/2007] [Accepted: 01/18/2007] [Indexed: 11/17/2022]
Abstract
PURPOSE To assess the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level using CT and MRI in patients with emphysema. MATERIAL AND METHODS Forty-five patients with severe emphysema (GOLD III and IV) underwent inspiratory 3D-HRCT and contrast-enhanced MR-perfusion (1.5T; 3.5mmx1.9mmx4mm). 3D-HRCT data was analyzed using a software for detection and visualization of emphysema. Emphysema was categorized in four clusters with different volumes and presented as overlay on the CT. CT and lung perfusion were visually analyzed for three lobes on each side using a four-point-score to grade the abnormalities on CT (1: predominantly small emphysema-clusters to 4: >75% large emphysema-clusters) and MRI (1: normal perfusion to 4: no perfusion). RESULTS A total of 270 lobes were evaluated. At CT, the score was 1 for 9 lobes, 2 for 43, 3 for 77, and 4 for 141 lobes. At MRI, the score was 1 for 13 lobes, 2 for 45, 3 for 92, and 4 for 120 lobes. Matching of lung parenchymal destruction and reduced perfusion was found in 213 lobes (weighted kappa=0.8). The score was higher on CT in 44, and higher on MRI in 13 lobes. CONCLUSION 3D-HRCT and 3D MR-perfusion show a high lobar agreement between parenchymal destruction and reduction of perfusion in patients with severe emphysema.
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Abstract
Emphysema is defined as a condition of the lung characterized by abnormal, permanent enlargement of airspaces distal to the terminal bronchiole accompanied by destruction of the alveolar walls and without obvious fibrosis. It is a very common disease with high morbidity and mortality. Histopathologically, there are two types of emphysema: panlobular emphysema, typically occurring in alpha1-antitrypsin deficiency, and centrilobular emphysema, which is strongly associated with cigarette smoking. Computed tomography (CT) allows detection of emphysema with higher sensitivity than conventional chest radiography and pulmonary function tests. CT also allows quantification of emphysema and depicts associated changes and complications. The differential diagnosis of emphysema, which is characterized by the absence of clearly definable walls on CT, includes cystic lung disease, bullae, lung laceration, Langerhans cell histiocytosis, and lymphangioleiomyomatosis -which are all characterized by visible walls on CT.
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Affiliation(s)
- C Grosse
- Institut für Radiodiagnostik, Medizinische Universität, Währinger Gürtel 18-20, A-1090, Wien, Austria.
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Zaporozhan J, Ley S, Eberhardt R, Weinheimer O, Iliyushenko S, Herth F, Kauczor HU. Paired Inspiratory/Expiratory Volumetric Thin-Slice CT Scan for Emphysema Analysis. Chest 2005; 128:3212-20. [PMID: 16304264 DOI: 10.1378/chest.128.5.3212] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSES The aim of the study was to use three-dimensional high-resolution CT scan data sets in inspiration and expiration for the quantitative evaluation of emphysema. Using an advanced dedicated semiautomatic analysis tool, the functional inspiratory/expiratory shifts of emphysema volume and clusters were quantified. The pulmonary function test (PFT) served as the clinical "gold standard." MATERIALS AND METHODS Thirty-one patients (9 women and 22 men; mean [+/- SD] age, 60 +/- 8 years) who had severe emphysema due to COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] class III and IV) were included in the study. All patients underwent paired inspiratory/expiratory multidetector CT scans (slice thickness, 1/0.8 mm) and pulmonary function tests (PFTs). CT scan data were analyzed with self-written emphysema detection solftware. It provides lung volume (LV), emphysema volume (EV), emphysema index (EI), and four clusters of emphysema with different volumes (from 2, 8, 65, and 120 mm(3)). These results were correlated with total lung capacity (TLC), intrathoracic gas volume (ITGV), and residual volume (RV) derived from PFT results. RESULTS Inspiratory LV correlated with TLC (r = 0.9), expiratory LV with ITGV (r = 0.87), and RV (r = 0.83). Expiratory EV correlated better with ITGV (r = 0.88) and RV (r = 0.93) than with inspiratory EV (r = 0.83 and 0.88, respectively). The mean inspiratory EI was 54 +/- 13%, and it decreased to 43 +/- 15% in expiration. However, the individuals showed a broad spectrum of changes of EI (mean, 11%; range, 1 to 28%), and no differences in inspiratory/expiratory EI and changes in EI or LV were found between GOLD III and GOLD IV patients. In expiration, there was a change from the large emphysema cluster (-37%) to the intermediate cluster (+15%) and small cluster (+13% and +11%, respectively). The change of volume of the large emphysema cluster after expiration correlated well with the changes in LV (r = 0.9), EV (r = 0.99), EI (r = 0.85), and MLD (r = 0.76). CONCLUSION Emphysema volumes measured from expiratory MDCT scans better reflect PFT abnormalities in patients with severe emphysema than those from inspiratory scans. Volumetric cluster analysis provided deeper insights into the local hyperinflation and expiratory obstruction of large emphysematous clusters.
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Affiliation(s)
- Julia Zaporozhan
- Department of Radiology, German Cancer Research Center, Heidelberg.
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Morbach AE, Gast KK, Schmiedeskamp J, Dahmen A, Herweling A, Heussel CP, Kauczor HU, Schreiber WG. Diffusion-weighted MRI of the lung with hyperpolarized helium-3: a study of reproducibility. J Magn Reson Imaging 2005; 21:765-74. [PMID: 15906344 DOI: 10.1002/jmri.20300] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To determine the reproducibility of several parameters of the ADC measurement by calculating the scan-to-scan intrasubject variability. MATERIALS AND METHODS Measurements were performed using a gradient-echo sequence with a bipolar gradient for diffusion weighting (b=3.89 sec/cm2). Five patients with pulmonary emphysema, and six healthy-lung volunteers were included in the study. Images were acquired after inspiration of 3He during a single inspiratory breath-hold. To assess the reproducibility, the measurement was performed twice (time between measurements=20 minutes) without repositioning the subjects. Analysis was performed on the basis of region-of-interest (ROI) analysis and global lung ADC histograms. RESULTS The mean ADC of a ROI varied by 5.1% between two measurements for volunteers and by 6.1% for patients. In the global evaluation, the 75th percentile demonstrated the best reproducibility (2%), while other parameters showed variations up to 12%. Only the variation of the standard deviation (SD) and the measure of homogeneity of the ADC map showed a significant difference between patients and volunteers. CONCLUSION Diffusion-weighted imaging (DWI) is a well-reproducible method for assessing the lung microstructure.
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Affiliation(s)
- Andreas E Morbach
- Department of Radiology, Johannes Gutenberg University Medical School, Mainz, Germany
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Abstract
Computed tomographic scanning may replace lung function tests as the golden standard for assessing the response to known and novel treatments for alpha1-antitrypsin deficiency.
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Affiliation(s)
- S B Shaker
- Department of Respiratory Medicine, Gentofte Hospital, DK-2900 Hellerup, Denmark.
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Ley S, Zaporozhan J, Morbach A, Eberle B, Gast KK, Heussel CP, Biedermann A, Mayer E, Schmiedeskamp J, Stepniak A, Schreiber WG, Kauczor HU. Functional evaluation of emphysema using diffusion-weighted 3Helium-magnetic resonance imaging, high-resolution computed tomography, and lung function tests. Invest Radiol 2004; 39:427-34. [PMID: 15194914 DOI: 10.1097/01.rli.0000129468.79005.1d] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To assess the emphysematous enlargement of distal airspaces and concomitant large and small airway disease using diffusion-weighted Helium-magnetic resonance imaging (MRI), high-resolution computed tomography (HRCT), and lung function tests (LFT). METHODS Seven patients were examined after single lung transplantation (LTx) and 1 before double LTx for various forms of emphysema. Five patients after double LTx served as controls. Patients were assessed by Helium-MRI (apparent diffusion coefficient [ADC]), HRCT (mean lung density [MLD], emphysema index [EI]), and LFT. RESULTS Transplanted lungs: mean ADC = 0.17 cm/s, MLD = -848 H, EI = 22%. Emphysematous lungs: mean ADC = 0.33 cm/s, MLD = -922 H; EI = 54%. Good correlations were found between ADC and MLD (r = 0.6), EI (r = 0.8), intrathoracic gas volume (r = 0.7), forced expiratory volume in 1 second (r = 0.7), and forced expiratory flows (r = 0.7). In contrast, HRCT only provided moderate correlations with LFT (EI: r = 0.5; MLD: r [le] 0.4). CONCLUSION In this initial study, He-MRI yield good correlations with HRCT and agrees better than HRCT with the functional characterization of emphysema regarding hyperinflation, large and small airway disease as provided by LFT.
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Affiliation(s)
- Sebastian Ley
- Department of Radiology, Johannes Gutenberg-University, Mainz, Germany.
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Abstract
Current research is providing new understanding in the pathophysiology of emphysema, and this knowledge will be translated in finding better modalities of therapy for patients currently affected by COPD. The single best effort that can alter the course of COPD is promoting policies to remove smoking as an available option to young people, before they become addicted and thus prey of tobacco-producing companies. Landmark studies like NETT and the GOLD initiative are providing tool classify emphysema in the context of physiological criteria and possible therapeutic alternatives.
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Affiliation(s)
- Cesar A Keller
- Mayo Clinic, 4205 Belfort Road, Suite 1100, Jacksonville, FL 32216, USA.
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Affiliation(s)
- Katherine P Grichnik
- Department of Anesthesiology, Division of Cardiothoracic Anesthesia, Duke Heart Center, Duke University Health Care Systems, Durham, NC 27710, USA.
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Salerno M, de Lange EE, Altes TA, Truwit JD, Brookeman JR, Mugler JP. Emphysema: hyperpolarized helium 3 diffusion MR imaging of the lungs compared with spirometric indexes--initial experience. Radiology 2002; 222:252-60. [PMID: 11756734 DOI: 10.1148/radiol.2221001834] [Citation(s) in RCA: 233] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To quantitatively evaluate hyperpolarized helium 3 ((3)He) diffusion magnetic resonance (MR) images of the lung in patients with emphysema and to determine whether apparent diffusion coefficients (ADCs) measured with MR imaging correlate with spirometric indexes. MATERIALS AND METHODS Hyperpolarized (3)He diffusion MR imaging was performed in 16 healthy volunteers and 11 patients. Coronal diffusion-sensitized MR images were obtained during suspended respiration after inhalation of laser-polarized (3)He gas, and images of the ADC were calculated. Spirometry was performed immediately before imaging. The mean and SD of the ADCs were compared between subject groups and were correlated with spirometric indexes. RESULTS ADC images were homogeneous in volunteers, but demonstrated regional variations in patients. The mean and SD of the ADCs for patients were significantly larger (P <.002) than those for volunteers. The mean ADCs for all subjects correlated with the percentage of predicted forced expiratory volume in 1 second, or FEV(1), (r = -0.797, P <.001) and the ratio of FEV(1) to forced vital capacity, or FVC, (r = -0.930, P <.001). ADC images in patients demonstrated a significant increase (P <.001) in the ADCs in the upper regions compared with the lower regions of the lung. CONCLUSION Hyperpolarized (3)He diffusion MR imaging demonstrated potential for use in evaluating the global and regional severity of emphysema.
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Affiliation(s)
- Michael Salerno
- Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology, University of Virginia School of Medicine, 1000 Lee St, Box 800170, Charlottesville, VA 22908, USA
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Abstract
This article focuses on three main topics: (1) the importance of emphysema as a serious respiratory disease, (2) qualitative assessment of emphysema using CT, and (3) the emerging importance of quantitative CT in the evaluation of patients with emphysema for surgery and drug therapy. CT also can identify the major anatomic subtypes of emphysema. CT is critical in the assessment of patients with the potential for lung volume reduction surgery. CT may well be superior to pulmonary function tests in the longitudinal assessment of current and proposed drug therapies for the treatment of emphysema.
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Affiliation(s)
- John D Newell
- Department of Radiology, University of Colorado Health Sciences Center, Denver, USA.
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24
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Abstract
Accurate diagnosis and quantification of pulmonary emphysema during life is important to understand the natural history of the disease, to assess the extent of the disease, and to evaluate and follow-up therapeutic interventions. Since pulmonary emphysema is defined through pathological criteria, new methods of diagnosis and quantification should be validated by comparisons against histological references. Recent studies have addressed the capability of computed tomography (CT) to quantify pulmonary emphysema accurately. The studies reviewed in this article have been based on CT scans obtained after deep inspiration or expiration, on subjective visual grading and on objective measurements of attenuation values. Especially dedicated software was used for this purpose, which provided numerical data, on both two- and three-dimensional approaches, and compared CT data with pulmonary function tests. More recently, fractal and textural analyses were applied to computed tomography scans to assess the presence, the extent, and the types of emphysema. Quantitative computed tomography has already been used in patient selection for surgical treatment of pulmonary emphysema and in pharmacotherapeutical trials. However, despite numerous and extensive studies, this technique has not yet been standardized and important questions about how best to use computed tomography for the quantification of pulmonary emphysema are still unsolved.
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Affiliation(s)
- A Madani
- Dept of Radiology, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
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