Short‐term reproducibility of computed tomography‐based lung density measurements in alpha‐1 antitrypsin deficiency and smokers with emphysema

Shaker, Saher Burhan; Dirksen, Asger; Laursen, L. C.; Maltbæk, Niels; Christensen, L. T.; Sander, Ulrich; Seersholm, Niels; Skovgaard, L. T.; Nielsen, Lars B.; Kok-Jensen, A

doi:10.1080/02841850410005642

Cited by 52 publications

(48 citation statements)

References 28 publications

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“…These typically include cross-sectional studies aiming to achieve a phenotyping characterization of patients with COPD [31,32,46] and longitudinal evaluation of emphysema in patients with α1-antitripsin deficiency treated with replacement therapy [36,37,47] or in patients with COPD before and after lung volume reduction surgery [38]. Low-dose protocols can be used for cross-sectional and longitudinal densitometry studies of emphysema and are especially recommended for the latter [48,49], but their application to evaluation of the small airways has not been evaluated so far. On the other hand, densitometry yields valuable data about the extent of emphysema, but is elusive about the size and distribution of the emphysematous changes [35].…”

Section: Discussionmentioning

confidence: 99%

Whole-lung densitometry versus visual assessment of emphysema

et al. 2009

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We compared whole-lung densitometry with visual evaluation of pulmonary emphysema. Thirty patients with chronic obstructive pulmonary disease underwent multi-detector CT (150 mAs and 0.75 collimation) with double reconstruction: thick (5-mm) slices with smooth filter for whole-lung densitometry and thin (1 mm) slices with sharp filter for visual assessment (one of every ten slices). Densitometry and visual assessment were performed by three operators each, and the time required for assessment, the inter-observer agreement and the correlation with the results of the diffusion capacity of carbon monoxide (DL(CO)) in the same patients were computed. The average time for densitometry (8.49 +/- 0.13 min) was significantly longer (p < 0.0001) than that for visual evaluation (5.14 +/- 0.11 min). However, the inter-operator agreement ranged between "moderate" to "almost perfect" for densitometry (kappa range 0.58-0.87) and "slight" for visual (kappa = 0.20) assessment. The correlation coefficients of DL(CO) with relative area at -960 and -970 Hounsfield units (HU) (both r = -0.66) and of the first percentile point of lung density (r = 0.66) were slightly stronger than that of the visual score (r = -0.62). Densitometry should be preferred to visual assessment because it enables a more reproducible evaluation of the extent of pulmonary emphysema, which can be carried out on the entire lung in a reasonable amount of time.

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Section: Discussionmentioning

confidence: 99%

Whole-lung densitometry versus visual assessment of emphysema

et al. 2009

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“…It is well known that change of scanner and/or reconstruction algorithm has a significant influence on the estimation of the degree of emphysema (39,40); therefore, we included the type of scanner and thus the scanner setting as an explanatory variable in the regression model. This factor added undoubtedly to the level of uncertainty (i.e., the variance) of the results and could be the cause of the lack of statistical significance for PD15.…”

Section: Discussionmentioning

confidence: 99%

The Effect of Inhaled Corticosteroids on the Development of Emphysema in Smokers Assessed by Annual Computed Tomography

Shaker

Dirksen

Ulrik

et al. 2009

COPD: Journal of Chronic Obstructive Pulmonary Disease

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The objective was to evaluate the effect of inhaled corticosteroids on disease progression in smokers with moderate to severe chronic obstructive pulmonary disease (COPD), as assessed by annual computed tomography (CT) using lung density (LD) measurements. Two hundred and fifty-four current smokers with COPD were randomised to treatment with either an inhaled corticosteroids (ICS), budesonide 400 microg bid, or placebo. COPD was defined as FEV(1) < or = 70% pred, FEV(1)/FVC < or = 60% and no reversibility to beta(2)-agonists and oral corticosteroids. The patients were followed for 2-4 years with biannual spirometry and annual CT and comprehensive lung function tests (LFT). CT images were analysed using Pulmo-CMS software. LD was derived from a pixel-density histogram of the whole lung as the 15th percentile density (PD15) and the relative area of emphysema at a threshold of -910 Hounsfield units (RA-910), and both were volume-adjusted to predicted total lung capacity. At baseline, mean age was 64 years and 64 years; mean number of pack-years was 56 and 56; mean FEV(1) was 1.53 L (51% pred) and 1.53 L (53% pred); mean PD15 was 103 g/L and 104 g/L; and mean RA-910 was 14% and 13%, respectively, for the budesonide and placebo groups. The annual fall in PD15 was -1.12 g/L in the budesonide group and -1.81 g/L in the placebo group (p = 0.09); the annual increase in RA-910 was 0.4% in the budesonide group and 1.1% in the placebo group (p = 0.02). There was no difference in annual decline in FEV(1) between ICS (-54 mL) and placebo (-56 mL) (p = 0.89). Long-term budesonide inhalation shows a non-significant trend towards reducing the progression of emphysema as determined by the CT-derived 15th percentile lung density from annual CT scans in current smokers with moderate to severe COPD.

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“…14Y16 Total lung volume (TLV), emphysema volume (EV), and 15th percentile density (PD15) were calculated for all patients in all reconstruction algorithms. 6,17 Furthermore, areas of emphysema were segmented into 4 clusters with different volumes (cluster 1, 0j8.2 mm3; cluster 2, 8.2j65.5 mm3; cluster 3, 65.5j118.8 mm3, cluster 4, 9118.8 mm3). This analysis provided the evaluation of changes between the clusters caused by different reconstruction algorithms.…”

Section: Methodsmentioning

confidence: 99%

Computer-Aided Measurements of Pulmonary Emphysema in Chest Multidetector-Row Spiral Computed Tomography

Behrendt

Das²,

Mahnken³

et al. 2008

Journal of Computer Assisted Tomography

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Short‐term reproducibility of computed tomography‐based lung density measurements in alpha‐1 antitrypsin deficiency and smokers with emphysema

Abstract: Lung density measurement by CT is a sensitive marker for quantitating both subtypes of emphysema. A CT-protocol with radiation dose down to 16 mAs and soft or detail reconstruction algorithm is recommended.

Cited by 52 publications

References 28 publications

Whole-lung densitometry versus visual assessment of emphysema

Whole-lung densitometry versus visual assessment of emphysema

The Effect of Inhaled Corticosteroids on the Development of Emphysema in Smokers Assessed by Annual Computed Tomography

Computer-Aided Measurements of Pulmonary Emphysema in Chest Multidetector-Row Spiral Computed Tomography

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