Goldin J G, McNitt-Gray M F, Sorenson S M, Johnson T D, Dauphinee B, Kleerup E C, Tashkin D P, Aberle D R
Dept of Radiological Sciences, UCLA School of Medicine 90095-1721, USA.
Radiology. 1998 Aug;208(2):321-9. doi: 10.1148/radiology.208.2.9680554.
To determine the accuracy of helical computed tomography (CT) for assessing reversible changes in bronchial size and air trapping due to airway hyperreactivity.
Spirometry and helical CT were performed in 15 patients with mild asthma and six healthy control subjects before and after bronchial provocation with methacholine chloride and after reversal of provocation with albuterol. CT was performed at suspended functional residual capacity and at residual volume in two lung regions (above and below the carina). Bronchial area and lung attenuation measurements were compared.
At baseline, lung attenuation frequency distribution curves were similar between the control and asthma groups. After methacholine, control subjects showed a decrease of less than 10% in the forced expiratory volume at 1 second (FEV1) and no significant differences in lung attenuation curves. Patients with asthma showed a 20%-36% decrease in FEV1, with significant decreases in the median and lowest 10th percentile regions of the attenuation curves and in the cross-sectional area of small (< 5-mm2) airways (P < .001 for all comparisons). After albuterol, control subjects showed no change in spirometric measurements, lung attenuation, or bronchial size, whereas all such parameters returned to baseline levels in patients with asthma.
Functional helical CT can accurately demonstrate reversible airflow obstruction resulting from airway hyperreactivity.
确定螺旋计算机断层扫描（CT）评估因气道高反应性导致的支气管大小可逆性变化和气体陷闭的准确性。
对15例轻度哮喘患者和6名健康对照者在使用氯化乙酰甲胆碱进行支气管激发前、后以及使用沙丁胺醇逆转激发后进行肺量计检查和螺旋CT检查。在两个肺区（隆突上方和下方）于功能残气量和残气量时进行CT检查。比较支气管面积和肺衰减测量值。
在基线时，对照组和哮喘组的肺衰减频率分布曲线相似。使用乙酰甲胆碱后，对照者1秒用力呼气量（FEV1）下降不到10%，肺衰减曲线无显著差异。哮喘患者FEV1下降20% - 36%，衰减曲线的中位数和最低第10百分位数区域以及小气道（< 5平方毫米）的横截面积显著下降（所有比较P <.001）。使用沙丁胺醇后，对照者肺量计测量值、肺衰减或支气管大小无变化，而哮喘患者所有这些参数均恢复至基线水平。
功能性螺旋CT能够准确显示由气道高反应性导致的可逆性气流阻塞。
