Respiratory impedance is correlated with airway narrowing in asthma using three-dimensional computed tomography
Respiratory impedance is correlated with airway narrowing in asthma using three-dimensional computed tomography
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DOI：
10.1111/cea.13083
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发表时间：
2018-03-01
影响因子：
6.1
通讯作者：
Suda, T.
中科院分区：
文献类型：
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作者：
Karayama, M.;Inui, N.;Suda, T.
背景呼吸阻抗包括呼吸系统的阻力和电抗，可以提供有关呼吸功能的详细信息。目的探讨哮喘患者基于影像的气道改变与呼吸阻抗的相关性。方法对72例哮喘患者和29例正常对照进行呼吸阻抗和肺活量测定。用三维CT测量第三代至第六代支气管腔内面积(Ai)和管壁厚度(WT)，并用体表面积(BSA、Ai/BSA和WT/BSA的平方根)进行调整。结果哮喘患者的呼吸阻抗显著增加，Ai/BSA降低，WT/BSA增加，与肺活量测定仪评估的无气流受限的患者相同。AI/BSA与5 Hz(R5)和20 Hz(R20)呼吸阻力呈负相关。R20与AI/BSA的相关性强于R5。AI/BSA与1秒用力呼气量/用力肺活量比值、预测1秒用力呼气量百分比、预测呼气中期流量百分比呈正相关。WT/BSA与肺活量和呼吸阻力无明显相关性。结论与临床相关呼吸阻力与呼吸道狭窄有关。
BackgroundRespiratory impedance comprises the resistance and reactance of the respiratory system and can provide detailed information on respiratory function. However, details of the relationship between impedance and morphological airway changes in asthma are unknown.ObjectiveWe aimed to evaluate the correlation between imaging-based airway changes and respiratory impedance in patients with asthma.MethodsRespiratory impedance and spirometric data were evaluated in 72 patients with asthma and 29 reference subjects. We measured the intraluminal area (Ai) and wall thickness (WT) of third- to sixth-generation bronchi using three-dimensional computed tomographic analyses, and values were adjusted by body surface area (BSA, Ai/BSA, and WT/the square root () of BSA).ResultsAsthma patients had significantly increased respiratory impedance, decreased Ai/BSA, and increased WT/BSA, as was the case in those without airflow limitation as assessed by spirometry. Ai/BSA was inversely correlated with respiratory resistance at 5Hz (R5) and 20Hz (R20). R20 had a stronger correlation with Ai/BSA than did R5. Ai/BSA was positively correlated with forced expiratory volume in 1second/forced vital capacity ratio, percentage predicted forced expiratory volume in 1second, and percentage predicted mid-expiratory flow. WT/BSA had no significant correlation with spirometry or respiratory impedance.Conclusions & Clinical RelevanceRespiratory resistance is associated with airway narrowing.