McNamara A E, Müller N L, Okazawa M, Arntorp J, Wiggs B R, Paré P D
University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, Canada.
J Appl Physiol (1985). 1992 Jul;73(1):307-16. doi: 10.1152/jappl.1992.73.1.307.
The exact site of airway narrowing in asthma and chronic obstructive pulmonary disease is unknown. High-resolution computed tomography (HRCT) is a sensitive noninvasive imaging technique that can be used to measure airway dimensions. After determining the optimal computed tomographic parameters using a phantom, we measured lobe volume and airway dimensions of isolated canine lung lobes at a transpulmonary pressure of 25 cmH2O. These measurements were repeated after deflation and administration of aerosolized saline and carbachol (256 mg/ml). Lobe volume decreased with all treatments. The maximal lobar volume change was 26% at 6 cmH2O after carbachol. Average airway lumen area decreased with all treatments. After carbachol, at transpulmonary pressures of 25, 15, 10, 8, and 6 cmH2O, lumen area decreased by 7.3 +/- 4.1, 62.0 +/- 4.9, 77.5 +/- 3.0, 31.9 +/- 9.0, and 95.2 +/- 1.0% (SE), respectively. When the airways were divided into four categories on the basis of initial lumen diameter (less than 2, 2-4, 4-6, and greater than 6 mm), the greatest decreases in luminal area after carbachol were seen in intermediate-sized airways (2-4 mm, 56 +/- 4%; 4-6 mm, 59 +/- 3%). HRCT can be used to make accurate measurements of airway dimensions and airway narrowing in excised lungs. HRCT may allow measurement of airway wall thickness and determination of the site of airway narrowing in asthma.
哮喘和慢性阻塞性肺疾病中气道狭窄的确切部位尚不清楚。高分辨率计算机断层扫描（HRCT）是一种敏感的非侵入性成像技术，可用于测量气道尺寸。在使用体模确定最佳计算机断层扫描参数后，我们在跨肺压为25 cmH2O时测量了离体犬肺叶的肺叶体积和气道尺寸。在放气并给予雾化盐水和卡巴胆碱（256 mg/ml）后重复这些测量。所有治疗后肺叶体积均减小。卡巴胆碱治疗后，在6 cmH2O时最大肺叶体积变化为26%。所有治疗后平均气道管腔面积均减小。卡巴胆碱治疗后，在跨肺压为25、15、10、8和6 cmH2O时，管腔面积分别减小7.3±4.1%、62.0±4.9%、77.5±3.0%、31.9±9.0%和95.2±1.0%（标准误）。当根据初始管腔直径将气道分为四类（小于2、2 - 4、4 - 6和大于6 mm）时，卡巴胆碱治疗后管腔面积减小最大的是中等大小的气道（2 - 4 mm，56±4%；4 - 6 mm，59±3%）。HRCT可用于准确测量离体肺的气道尺寸和气道狭窄情况。HRCT可能有助于测量气道壁厚度并确定哮喘中气道狭窄的部位。
