Asynchrony in respiratory movements between the pulmonary lobes in patients with COPD: continuous measurement of lung density by 4-dimensional dynamic-ventilation CT

Yamashiro, Tsuneo; Moriya, Hideshige; Matsuoka, Shin; Nagatani, Yukihiro; Tsubakimoto, Maho; Tsuchiya, Nanae; Murayama, Sadayuki

doi:10.2147/copd.s140247

Cited by 28 publications

(21 citation statements)

References 27 publications

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“…Although previous studies indicated that ventilation defects could be detected as decreased changes in radiographic lung density [8,25], further studies are Respiration 2020;99:382-388 DOI: 10.1159/000506881 needed to confirm the relationship between pulmonary function and changes in radiographic lung density. Third, it has been reported that the synchrony of respiratory movements between the pulmonary lobes is limited or lost in patients with more severe airflow limitation in the study using 4-dimensional dynamic-ventilation CT [26]. Although this study focused on the rate of change in the lung area, future studies need to find indices that indicate nonuniformity in respiratory movement using dynamicventilatory DR and show their associations with respiratory function and symptoms.…”

Section: Discussionmentioning

confidence: 93%

Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping

et al. 2020

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Objective: The aim of this study was to determine the utility of dynamic-ventilatory digital radiography (DR) for pulmonary function assessment in patients with airflow limitation. Methods: One hundred and eighteen patients with airflow limitation (72 patients with lung cancer before surgery, 35 patients with chronic obstructive pulmonary disease [COPD], 6 patients with asthma, and 5 patients with asthma-COPD overlap syndrome) were assessed with dynamic-ventilatory DR. The patients were instructed to inhale and exhale slowly and maximally. Sequential chest X-ray images were captured in 15 frames per second using a dynamic flat-panel imaging system. The relationship between the lung area and the rate of change in the lung area due to respiratory motion with respect to pulmonary function was analyzed. Results:The rate of change in the lung area from maximum inspiration to maximum expiration (Rs ratio) was associated with the RV/TLC ratio (r = 0.48, p < 0.01) and the percentage of the predicted FEV 1 (r = -0.33, p < 0.01) in patients with airflow limitations. The Rs ratio also decreased in an FEV 1 -dependent manner. Conclusion: The rate of change in the lung area due to respiratory motion evaluated with dynamic DR reflects air trapping. Dynamic DR is a potential tool for the comprehensive assessment of pulmonary function in patients with COPD.

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Section: Discussionmentioning

confidence: 93%

Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping

et al. 2020

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“…In patients with COPD, the destruction of normal “mesh-like” structures of pulmonary tissue results in pulmonary emphysema and leads to a reduction of lung compliance, causing inhomogeneous transmission of lung motion during the respiratory cycle 14. Furthermore, the heterogeneous distribution of emphysematous changes and airway diseases also intensify the heterogeneity of lung movement during ventilation,15–17 which has been clearly confirmed in recent studies using 4D dynamic-ventilation CT and other imaging techniques 18–20. These recent studies have demonstrated the existence of asynchrony between the right and left lungs, between the proximal airways and lung, and among different lung lobes.…”

Section: Introductionmentioning

confidence: 71%

“…This study was also part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research alliance in Japan. Also, the subjects’ data utilized in this study were previously analyzed with a different objective for other research 20…”

Section: Methodsmentioning

confidence: 99%

Strain measurement on four-dimensional dynamic-ventilation CT: quantitative analysis of abnormal respiratory deformation of the lung in COPD

Yamashiro

Moriya

et al. 2018

COPD

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PurposeStrain measurement is frequently used to assess myocardial motion in cardiac imaging. This study aimed to apply strain measurement to pulmonary motion observed by four-dimensional dynamic-ventilation computed tomography (CT) and to clarify motion abnormality in COPD.Materials and methodsThirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during spontaneous breathing. CT data were continuously reconstructed every 0.5 seconds. In the series of images obtained by dynamic-ventilation CT, five expiratory frames were identified starting from the peak inspiratory frame (first expiratory frame) and ending with the fifth expiratory frame. Strain measurement of the scanned lung was performed using research software that was originally developed for cardiac strain measurement and modified for assessing deformation of the lung. The measured strain values were divided by the change in mean lung density to adjust for the degree of expiration. Spearman’s rank correlation analysis was used to evaluate associations between the adjusted strain measurements and various spirometric values.ResultsThe adjusted strain measurement was negatively correlated with FEV1/FVC (ρ=−0.52, P<0.01), maximum mid-expiratory flow (ρ=−0.59, P<0.001), and peak expiratory flow (ρ=−0.48, P<0.01), suggesting that abnormal deformation of lung motion is related to various patterns of expiratory airflow limitation.ConclusionAbnormal deformation of lung motion exists in COPD patients and can be quantitatively assessed by strain measurement using dynamic-ventilation CT. This technique can be expanded to dynamic-ventilation CT in patients with various lung and airway diseases that cause abnormal pulmonary motion.

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“…Hence, we believe that this FV curve pattern is associated with a poorer prognosis and reduced BMI. Observation of the movement of the lung using 4D CT analysis has been recently attracting attention [25]. Future studies using a detailed analysis of lung movement are warranted to prove and establish our hypothesis regarding the heterogeneous movement of the thorax in this category of patients.…”

Section: Discussionmentioning

confidence: 99%

Relationship of flow-volume curve pattern on pulmonary function test with clinical and radiological features in idiopathic pulmonary fibrosis

et al. 2020

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Background: The flow-volume (FV) curve pattern in the pulmonary function test (PFT) for obstructive lung diseases is widely recognized. However, there are few reports on FV curve pattern in idiopathic pulmonary fibrosis (IPF). In this study, we investigated the relationship between FV curve pattern and clinical or radiological features in IPF. Methods: The FV curves on PFTs and chest high-resolution computed tomography (HRCT) images of 130 patients with IPF were retrospectively evaluated. The FV curves were divided into four groups based on the presence or absence of the convex and concave patterns: convex/concave, non-convex/concave, convex/non-concave, and non-convex/non-concave. Using a computer-aided system, CT honeycombing area (%HA) and subtracted low attenuation area (%sLAA) were quantitatively measured. To assess the distribution of CT findings, the lung area was divided into upper, lower, central, and peripheral areas. The relationships of FV curve patterns with patient characteristics, spirometry results, and quantitative CT findings were evaluated. Results: The patients with convex pattern was identified in 93 (71.5%) and concave pattern in 72 (55.4%). Among the four groups, patients with the convex/non-concave pattern had significantly lower forced vital capacity (FVC) and higher %HA of the upper/peripheral lung area (p = 0.018, and p = 0.005, respectively). The convex/non-concave pattern was a significant predictor of mortality for IPF (hazard ratio, 2.19; p = 0.032). Conclusions: Patients with convex/non-concave pattern in FV curve have lower FVC and poorer prognosis with distinct distribution of fibrosis. Hence, FV curve pattern might be a useful predictor of mortality in IPF.

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Asynchrony in respiratory movements between the pulmonary lobes in patients with COPD: continuous measurement of lung density by 4-dimensional dynamic-ventilation CT

Cited by 28 publications

References 27 publications

Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping

Dynamic-Ventilatory Digital Radiography in Air Flow Limitation: A Change in Lung Area Reflects Air Trapping

Strain measurement on four-dimensional dynamic-ventilation CT: quantitative analysis of abnormal respiratory deformation of the lung in COPD

Relationship of flow-volume curve pattern on pulmonary function test with clinical and radiological features in idiopathic pulmonary fibrosis

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