PloS one · 2014
Effect of lung volume on airway luminal area assessed by computed tomography in chronic obstructive pulmonary disease.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Kambara Kenta, Shimizu Kaoruko, Makita Hironi, Hasegawa Masaru, Nagai Katsura, Konno Satoshi, Nishimura Masaharu
Аннотация
BACKGROUND: Although airway luminal area (Ai) is affected by lung volume (LV), how is not precisely understood. We hypothesized that the effect of LV on Ai would differ by airway generation, lung lobe, and chronic obstructive pulmonary disease (COPD) severity.
METHODS: Sixty-seven subjects (15 at risk, 18, 20, and 14 for COPD stages 1, 2, and 3) underwent pulmonary function tests and computed tomography scans at full inspiration and expiration (at functional residual capacity). LV and eight selected identical airways were measured in the right lung. Ai was measured at the mid-portion of the 3(rd), the segmental bronchus, to 6(th) generation of the airways, leading to 32 measurements per subject.
RESULTS: The ratio of expiratory to inspiratory LV (LV E/I ratio) and Ai (Ai E/I ratio) was defined for evaluation of changes. The LV E/I ratio increased as COPD severity progressed. As the LV E/I ratio was smaller, the Ai E/I ratio was smaller at any generation among the subjects. Overall, the Ai E/I ratios were significantly smaller at the 5(th) (61.5%) and 6(th) generations (63.4%) and than at the 3(rd) generation (73.6%, p<0.001 for each), and also significantly lower in the lower lobe than in the upper or middle lobe (p<0.001 for each). And, the Ai E/I ratio decreased as COPD severity progressed only when the ratio was corrected by the LV E/I ratio (at risk v.s. stage 3 p<0.001, stage 1 v.s. stage 3 p<0.05).
CONCLUSIONS: From full inspiration to expiration, the airway luminal area shrinks more at the distal airways compared with the proximal airways and in the lower lobe compared with the other lobes. Generally, the airways shrink more as COPD severity progresses, but this phenomenon becomes apparent only when lung volume change from inspiration to expiration is taken into account.
METHODS: Sixty-seven subjects (15 at risk, 18, 20, and 14 for COPD stages 1, 2, and 3) underwent pulmonary function tests and computed tomography scans at full inspiration and expiration (at functional residual capacity). LV and eight selected identical airways were measured in the right lung. Ai was measured at the mid-portion of the 3(rd), the segmental bronchus, to 6(th) generation of the airways, leading to 32 measurements per subject.
RESULTS: The ratio of expiratory to inspiratory LV (LV E/I ratio) and Ai (Ai E/I ratio) was defined for evaluation of changes. The LV E/I ratio increased as COPD severity progressed. As the LV E/I ratio was smaller, the Ai E/I ratio was smaller at any generation among the subjects. Overall, the Ai E/I ratios were significantly smaller at the 5(th) (61.5%) and 6(th) generations (63.4%) and than at the 3(rd) generation (73.6%, p<0.001 for each), and also significantly lower in the lower lobe than in the upper or middle lobe (p<0.001 for each). And, the Ai E/I ratio decreased as COPD severity progressed only when the ratio was corrected by the LV E/I ratio (at risk v.s. stage 3 p<0.001, stage 1 v.s. stage 3 p<0.05).
CONCLUSIONS: From full inspiration to expiration, the airway luminal area shrinks more at the distal airways compared with the proximal airways and in the lower lobe compared with the other lobes. Generally, the airways shrink more as COPD severity progresses, but this phenomenon becomes apparent only when lung volume change from inspiration to expiration is taken into account.