Airflow Limitation in Chronic Obstructive Pulmonary Disease: Ratio and Difference of Percentage of Low-attenuation Lung Regions in Paired Inspiratory/Expiratory Computed Tomography

作者：Nishio Mizuho^*; Matsumoto Sumiaki; Koyama Hisanobu; Ohno Yoshiharu; Sugimura Kazuro

来源：Academic Radiology, 2014, 21(10): 1262-1267.

DOI：10.1016/j.acra.2014.05.020

• COPD
• emphysema
• quantification
• CT

Rationale and Objectives: The purpose of this study was to analyze the relationship between airflow limitation and two types of computed tomography (CT) measurements: expiratory/inspiratory (E/I) ratio and E/I difference of percentage of low-attenuation lung regions (LAA%). %26lt;br%26gt;Materials and Methods: Thirty patients who underwent inspiratory and expiratory CT scans were included in this study. The CT data were used to calculate the LAA% E/I ratio and E/I difference. Other types of CT measurements were also obtained, including the E/I ratio and E/I difference of lung volume, mean lung density, standard deviation, skewness, and kurtosis. LAA% was calculated at 20 thresholds (-990 to -800 HU). Pearson%26apos;s correlation between the measurements and forced expiratory flow in 1 second was used to determine the efficacy of LAA% E/I ratio and E/I difference. P values of %26lt;5.88 x 10(-5) were considered statiatically significant with Bonferroni correction. %26lt;br%26gt;Results; The LAA% E/I ratio and E/I difference significantly correlated with forced expiratory flow in 1 second. The best correlation coefficient for the LAA% E/I ratio was -0.699 (P = 1.75 x 10(-5)) and for the LAA% E/I difference was -0.728 (P = 6.53 x 10(-6)). The best correlation coefficient for the LAA% E/I difference was stronger than that for the other types of CT measurements. %26lt;br%26gt;Conclusions: The LAA% E/I ratio and E/I difference significantly correlated with airflow limitation in chronic obstructive pulmonary disease.

• 出版日期2014-10