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Continuous quantitative measurement of the proximal airway dimensions and lung density on four-dimensional dynamic-ventilation CT in smokers.

Yamashiro T, Moriya H, Tsubakimoto M, Matsuoka S, Murayama S - Int J Chron Obstruct Pulmon Dis (2016)

Bottom Line: Concordance between the time curve of the MLD and that of the airway Ai values was expressed by cross-correlation coefficients.This suggested that the synchrony between the airway and lung movement was lost in patients with severe airflow limitation.Respiratory changes in the MLD and synchrony between the airway Ai and the MLD measured with dynamic-ventilation CT were correlated with patient's spirometric values.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.

ABSTRACT

Purpose: Four-dimensional dynamic-ventilation computed tomography (CT) imaging demonstrates continuous movement of the airways and lungs, which cannot be depicted with conventional CT. We aimed to investigate continuous changes in lung density and airway dimensions and to assess the correlation with spirometric values in smokers.

Materials and methods: This retrospective study was approved by the Institutional Review Board, and informed consent was waived. Twenty-one smokers including six patients with COPD underwent four-dimensional dynamic-ventilation CT during free breathing (160 mm in length). The mean lung density (MLD) of the scanned lung and luminal areas (Ai) of fixed points in the trachea and the right proximal bronchi (main bronchus, upper bronchus, bronchus intermedius, and lower bronchus) were continuously measured. Concordance between the time curve of the MLD and that of the airway Ai values was expressed by cross-correlation coefficients. The associations between these quantitative measurements and the forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) values were assessed by Spearman's rank correlation analysis.

Results: On the time curve for the MLD, the Δ-MLD1.05 values between the peak inspiratory frame to the later third frame (1.05 seconds later) were strongly correlated with the FEV1/FVC (ρ=0.76, P<0.0001). The cross-correlation coefficients between the airway Ai and MLD values were significantly correlated with the FEV1/FVC (ρ=-0.56 to -0.66, P<0.01), except for the right upper bronchus. This suggested that the synchrony between the airway and lung movement was lost in patients with severe airflow limitation.

Conclusion: Respiratory changes in the MLD and synchrony between the airway Ai and the MLD measured with dynamic-ventilation CT were correlated with patient's spirometric values.

No MeSH data available.


Related in: MedlinePlus

An example of a small cross-correlation between the mean lung density and airway luminal area in a female patient with COPD (FEV1/FVC =0.53).Notes: It is unclear that two time curves of the MLD and the bronchial Ai (bronchus intermedius) move in an opposite direction (cross-correlation coefficient =−0.21). Furthermore, it is repeatedly observed that the Ai of the bronchus intermedius strangely decreases during inspiratory phases (arrowheads), suggesting the presence of paradoxical airway movement.Abbreviations: FEV1/FVC, forced expiratory volume in 1 second/forced vital capacity; Ai, luminal area; MLD, mean lung density; BI, bronchus intermedius.
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f4-copd-11-755: An example of a small cross-correlation between the mean lung density and airway luminal area in a female patient with COPD (FEV1/FVC =0.53).Notes: It is unclear that two time curves of the MLD and the bronchial Ai (bronchus intermedius) move in an opposite direction (cross-correlation coefficient =−0.21). Furthermore, it is repeatedly observed that the Ai of the bronchus intermedius strangely decreases during inspiratory phases (arrowheads), suggesting the presence of paradoxical airway movement.Abbreviations: FEV1/FVC, forced expiratory volume in 1 second/forced vital capacity; Ai, luminal area; MLD, mean lung density; BI, bronchus intermedius.

Mentions: The cross-correlation coefficients between the airway Ai and the MLD were significantly correlated with the FEV1/FVC (ρ=−0.56 to −0.66, P<0.01), except for in the RUB (Table 4; Figure 4). This suggested that the synchrony between the airway and lung movements was lost in patients with severe airflow limitation, except for in the RUB.


Continuous quantitative measurement of the proximal airway dimensions and lung density on four-dimensional dynamic-ventilation CT in smokers.

Yamashiro T, Moriya H, Tsubakimoto M, Matsuoka S, Murayama S - Int J Chron Obstruct Pulmon Dis (2016)

An example of a small cross-correlation between the mean lung density and airway luminal area in a female patient with COPD (FEV1/FVC =0.53).Notes: It is unclear that two time curves of the MLD and the bronchial Ai (bronchus intermedius) move in an opposite direction (cross-correlation coefficient =−0.21). Furthermore, it is repeatedly observed that the Ai of the bronchus intermedius strangely decreases during inspiratory phases (arrowheads), suggesting the presence of paradoxical airway movement.Abbreviations: FEV1/FVC, forced expiratory volume in 1 second/forced vital capacity; Ai, luminal area; MLD, mean lung density; BI, bronchus intermedius.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4835141&req=5

f4-copd-11-755: An example of a small cross-correlation between the mean lung density and airway luminal area in a female patient with COPD (FEV1/FVC =0.53).Notes: It is unclear that two time curves of the MLD and the bronchial Ai (bronchus intermedius) move in an opposite direction (cross-correlation coefficient =−0.21). Furthermore, it is repeatedly observed that the Ai of the bronchus intermedius strangely decreases during inspiratory phases (arrowheads), suggesting the presence of paradoxical airway movement.Abbreviations: FEV1/FVC, forced expiratory volume in 1 second/forced vital capacity; Ai, luminal area; MLD, mean lung density; BI, bronchus intermedius.
Mentions: The cross-correlation coefficients between the airway Ai and the MLD were significantly correlated with the FEV1/FVC (ρ=−0.56 to −0.66, P<0.01), except for in the RUB (Table 4; Figure 4). This suggested that the synchrony between the airway and lung movements was lost in patients with severe airflow limitation, except for in the RUB.

Bottom Line: Concordance between the time curve of the MLD and that of the airway Ai values was expressed by cross-correlation coefficients.This suggested that the synchrony between the airway and lung movement was lost in patients with severe airflow limitation.Respiratory changes in the MLD and synchrony between the airway Ai and the MLD measured with dynamic-ventilation CT were correlated with patient's spirometric values.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.

ABSTRACT

Purpose: Four-dimensional dynamic-ventilation computed tomography (CT) imaging demonstrates continuous movement of the airways and lungs, which cannot be depicted with conventional CT. We aimed to investigate continuous changes in lung density and airway dimensions and to assess the correlation with spirometric values in smokers.

Materials and methods: This retrospective study was approved by the Institutional Review Board, and informed consent was waived. Twenty-one smokers including six patients with COPD underwent four-dimensional dynamic-ventilation CT during free breathing (160 mm in length). The mean lung density (MLD) of the scanned lung and luminal areas (Ai) of fixed points in the trachea and the right proximal bronchi (main bronchus, upper bronchus, bronchus intermedius, and lower bronchus) were continuously measured. Concordance between the time curve of the MLD and that of the airway Ai values was expressed by cross-correlation coefficients. The associations between these quantitative measurements and the forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) values were assessed by Spearman's rank correlation analysis.

Results: On the time curve for the MLD, the Δ-MLD1.05 values between the peak inspiratory frame to the later third frame (1.05 seconds later) were strongly correlated with the FEV1/FVC (ρ=0.76, P<0.0001). The cross-correlation coefficients between the airway Ai and MLD values were significantly correlated with the FEV1/FVC (ρ=-0.56 to -0.66, P<0.01), except for the right upper bronchus. This suggested that the synchrony between the airway and lung movement was lost in patients with severe airflow limitation.

Conclusion: Respiratory changes in the MLD and synchrony between the airway Ai and the MLD measured with dynamic-ventilation CT were correlated with patient's spirometric values.

No MeSH data available.


Related in: MedlinePlus