Matsushita Shoichiro, Matsuoka Shin, Yamashiro Tsuneo, Fujikawa Atsuko, Kurihara Yasuyuki, Yagihashi Kunihiro, Handa Hiroshi, Miyazawa Teruomi, Nakajima Yasuo
From the *Department of Radiology, †Division of Respiratory and Infectious Diseases, Department of Internal Medicine, St Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
J Comput Assist Tomogr. 2014 Nov-Dec;38(6):968-71. doi: 10.1097/RCT.0000000000000130.
The purpose of this study was to evaluate the relationship between quantitative computed tomography (CT) parameters of air trapping obtained with inspiratory and expiratory CT and pulmonary function tests (PFTs) in patients with relapsing polychondritis (RP).
This study included 23 patients with RP who underwent both CT and PFTs. In each patient, the mean lung density (MLD) was obtained by averaging CT attenuation of the lung parenchyma on both inspiratory and expiratory CT. The ratio of expiratory MLD to inspiratory MLD (E/I ratio) was also calculated. Correlations between those quantitative CT measurements and the results of PFTs were evaluated using Spearman rank correlation.
The expiratory MLD and E/I ratio were significantly correlated with forced expiratory volume in 1 second (FEV1) %predicted, ratio of FEV1 to FVC (FEV1/FVC), and the mid expiratory phase of forced expiratory flow (FEF25%-75%) %predicted (expiratory MLD: FEV1 %predicted, r = 0.764, P < 0.0001; FEV1/FVC, r = 0.764, P < 0.0001; FEF25%-75% %predicted, r = 0.674, P < 0.001, respectively; the E/I ratio: FEV1 %predicted, r = -0.689, P < 0.001; FEV1/FVC, r = -0.689, P < 0.001; FEF25%-75% %predicted, r = -0.586, P < 0.01, respectively). The correlation between inspiratory MLD and PFTs did not reach statistical significance.
In RP patients, air trapping demonstrated on expiratory CT correlated with airway obstruction. This study may assist further refinement of the use of CT as quantitative evaluation for small and large airway obstruction in RP.
本研究旨在评估复发性多软骨炎（RP）患者吸气和呼气CT获得的空气潴留定量CT参数与肺功能测试（PFT）之间的关系。
本研究纳入了23例接受CT和PFT检查的RP患者。在每位患者中，通过对吸气和呼气CT上肺实质的CT衰减值求平均来获得平均肺密度（MLD）。还计算了呼气MLD与吸气MLD的比值（E/I比值）。使用Spearman等级相关性评估这些定量CT测量值与PFT结果之间的相关性。
呼气MLD和E/I比值与预测的1秒用力呼气容积（FEV1）%、FEV1与用力肺活量的比值（FEV1/FVC）以及用力呼气流量的呼气中期（FEF25%-75%）%预测值显著相关（呼气MLD：预测的FEV1%，r = 0.764，P < 0.0001；FEV1/FVC，r = 0.764，P < 0.0001；预测的FEF25%-75%，r = 0.674，P < 0.001；E/I比值：预测的FEV1%，r = -0.689，P < 0.001；FEV1/FVC，r = -0.689，P < 0.001；预测的FEF25%-75%，r = -0.586，P < 0.01）。吸气MLD与PFT之间的相关性未达到统计学显著性。
在RP患者中，呼气CT上显示的空气潴留与气道阻塞相关。本研究可能有助于进一步完善CT在RP中小气道和大气道阻塞定量评估中的应用。
