Reproducibility of volume and densitometric measures of emphysema on repeat computed tomography with an interval of 1 week

Chong, Daniel; Brown, Matthew S.; Kim, Hee Jin; Rikxoort, Eva M. van; Guzmán, Laura María Díaz; McNitt-Gray, Michael F.; Khatonabadi, M; Galperin-Aizenberg, Maya; Coy, Heidi; Yang, Katherine; Jung, Yongha; Goldin, Jonathan G.

doi:10.1007/s00330-011-2277-1

Cited by 25 publications

(18 citation statements)

References 25 publications

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“…The lung tissue was then further divided by adding the pixels within pre-defined CT attenuation limits in volumes and was then expressed as percentage of the entire lung volume [4,17]. Volumes in the range -300 to -750 HU were considered to represent pixels including tissue such as small bronchi, vessels and borders with denser structures (partial volume effect) and were analysed separately.…”

Section: Methodsmentioning

confidence: 99%

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Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers

Karimi¹,

Tornling²,

Forsslund³

et al. 2014

Respir Res

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BackgroundSmokers have increased cell concentration in the lower respiratory tract indicating a chronic inflammatory state, which in some individuals may lead to development of chronic obstructive pulmonary disease (COPD). Computer tomography (CT) imaging provides means of quantifying pulmonary structure and early signs of disease. We investigated whether lung density on high resolution CT differs between smokers and never-smokers and if this were associated to intensity of inflammation.MethodsForty smoking volunteers with normal pulmonary function, 40 healthy never-smokers and 40 patients with COPD of GOLD stage I-II, were included. Mean lung attenuation and percentage of pixels in the lung with attenuation between −750 and −900 HU (percentage higher density spectrum (%HDS)) were calculated on inspiratory CT-scans. Markers of systemic inflammation in blood and cell counts in bronchoalveolar lavage (BAL) fluid were recorded.ResultsLung density expressed as %HDS was increased in smokers (44.0 ± 5.8%) compared to both never-smokers (38.3 ± 5.8%) and patients with COPD (39.1 ± 5.8%), (p < 0.001, for both). Females had denser lungs than males, which was dependent on body height. Cell concentration in BAL were correlated to lung density in smokers (r = 0.50, p < 0.001).ConclusionsLung density on CT is associated with cell concentration in BAL in smokers and may mirror an inflammatory response in the lung. Gender difference in lung density is dependent on height. In COPD with emphysema, loss of lung tissue may counterbalance the expected increase in density due to inflammation. The findings may help to interpret high resolution CT in the context of smoking and gender and highlight the heterogeneity of structural changes in COPD.

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Section: Methodsmentioning

confidence: 99%

“…Computer tomography (CT) imaging of the lung can non-invasively detect and quantify lung abnormalities [4-7]. Early changes in airways and lung parenchyma may be recognized in smoking individuals with normal pulmonary function before any signs of lung function impairment [8,9].…”

Section: Introductionmentioning

confidence: 99%

Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers

Karimi¹,

Tornling²,

Forsslund³

et al. 2014

Respir Res

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“…Quantitative CT techniques for emphysema scoring are objective and therefore preferable to visual analysis (7). Recent studies have also demonstrated that CT lobar volumetry has good inter scan reproducibility (8)(9)(10). Among the different sources of variability of CT lung volumetry and emphysema scoring, those depending on the method used for lobar segmentation have received little attention (5).…”

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confidence: 99%

Intra- and interoperator variability of lobar pulmonary volumes and emphysema scores in patients with chronic obstructive pulmonary disease and emphysema: comparison of manual and semi-automated segmentation techniques

Molinari¹,

Pirronti²,

Sverzellati³

et al. 2013

Diagn Interv Radiol

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ORIGINAL ARTICLE PURPOSE We aimed to compare the intra-and interoperator variability of lobar volumetry and emphysema scores obtained by semi-automated and manual segmentation techniques in lung emphysema patients. MATERIALS AND METHODSIn two sessions held three months apart, two operators performed lobar volumetry of unenhanced chest computed tomography examinations of 47 consecutive patients with chronic obstructive pulmonary disease and lung emphysema. Both operators used the manual and semi-automated segmentation techniques. The intra-and interoperator variability of the volumes and emphysema scores obtained by semi-automated segmentation was compared with the variability obtained by manual segmentation of the five pulmonary lobes. RESULTSThe intra-and interoperator variability of the lobar volumes decreased when using semi-automated lobe segmentation 166.9 vs. 68.7; and left lower lobe, 168.7 vs. 71.6). The coefficients of repeatability and reproducibility of emphysema scores also decreased when using semi-automated segmentation and had ranges that varied depending on the target lobe and selected threshold of emphysema. CONCLUSION Semi-automated segmentation reduces the intra-and interoperator variability of lobar volumetry and provides a more objective tool than manual technique for quantifying lung volumes and severity of emphysema.

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“…However, to be able to detect disease progression or effects of therapy, variation between examinations should be within acceptable limits as disease progression is defined as an increase above the upper limit of such variation. The variation with the limits of agreement for repeat CT studies in emphysema is known [8, 9]; however, to our knowledge no information is available on the variation of CT air trapping quantification. Therefore, the objective of this study was to determine the variation in two commonly used quantitative CT air trapping measures in current and former heavy smokers.…”

Section: Introductionmentioning

confidence: 99%

Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations

et al. 2012

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ObjectivesTo determine the variation in quantitative computed tomography (CT) measures of air trapping in low-dose chest CTs of heavy smokers.MethodsWe analysed 45 subjects from a lung cancer screening trial, examined by CT twice within 3 months. Inspiratory and expiratory low-dose CT was obtained using breath hold instructions. CT air trapping was defined as the percentage of voxels in expiratory CT with an attenuation below −856 HU (EXP−856) and the expiratory to inspiratory ratio of mean lung density (E/I-ratioMLD). Variation was determined using limits of agreement, defined as 1.96 times the standard deviation of the mean difference. The effect of both lung volume correction and breath hold reproducibility was determined.ResultsThe limits of agreement for uncorrected CT air trapping measurements were −15.0 to 11.7 % (EXP−856) and −9.8 to 8.0 % (E/I-ratioMLD). Good breath hold reproducibility significantly narrowed the limits for EXP−856 (−10.7 to 7.5 %, P = 0.002), but not for E/I-ratioMLD (−9.2 to 7.9 %, P = 0.75). Statistical lung volume correction did not improve the limits for EXP−856 (−12.5 to 8.8 %, P = 0.12) and E/I-ratioMLD (−7.5 to 5.8 %, P = 0.17).ConclusionsQuantitative air trapping measures on low-dose CT of heavy smokers show considerable variation on repeat CT examinations, regardless of lung volume correction or reproducible breath holds.Key Points• Computed tomography quantitatively measures small airways disease in heavy smokers.• Measurements of air trapping vary considerably on repeat CT examinations.• Variation remains substantial even with reproducible breath holds and lung volume correction.

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Reproducibility of volume and densitometric measures of emphysema on repeat computed tomography with an interval of 1 week

Cited by 25 publications

References 25 publications

Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers

Lung density on high resolution computer tomography (HRCT) reflects degree of inflammation in smokers

Intra- and interoperator variability of lobar pulmonary volumes and emphysema scores in patients with chronic obstructive pulmonary disease and emphysema: comparison of manual and semi-automated segmentation techniques

Variation in quantitative CT air trapping in heavy smokers on repeat CT examinations

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