胸部CT定量技术对慢性阻塞性肺疾病病人心肺功能的评估价值

目的探讨胸部CT定量技术评估慢性阻塞性肺疾病（COPD）病人肺功能的应用价值。方法选取单纯COPD病人95例，采用胸部CT定量技术检测并比较不同病情程度病人的CT参数低衰减面积百分比（LAA%）、吸气末肺容积/呼气末肺容积（Vex/Vin）、呼气末与吸气末CT平均肺密度比值MLD（ex/in）]、最低1%肺衰减值（Prec1）、最低15%衰减值（Prec15）]、肺功能检测结果肺总量（TLC）、残气量（RV）、RV/TLC、用力肺活量（FVC）、第1秒用力呼气量（FEV1）、FEV1/FVC、FEV1占预计值百分比（FEV1%）]、心脏指标左心室射血分数（LVEF）、左心室内径（LVD）、左心房内径（LAD）、右心室内径（RVD）、右心房内径（RAD）]。另选取拟行手术治疗的肺癌合并COPD病人53例，比较不同术后心肺并发症发生情况病人的CT参数，并采用受试者工作特征曲线分析CT参数对病人预后的预测价值。结果随着COPD病人病情程度加重，LAA总占比、右肺占比、左肺占比、Vex/Vin、EI、MLD（ex/in）、Prec1、Prec15均呈升高趋势，FVC、FEV1、FEV1%、FEV1/FVC均呈降低趋势，RV、TLC、RV/TLC呈升高趋势，RVD呈升高趋势，LVEF呈降低趋势，不同病情程度病人以上参数间差异均有统计学意义（P < 0.05~P < 0.01）。LAA%、Vex/Vin、EI、MLD（ex/in）、Prec1、Prec15与FVC、FEV1、FEV1%、FEV1/FVC、LVEF均呈负相关关系，与RV、TLC、RV/TLC、RVD均呈正相关关系（P < 0.05~P < 0.01）。53例病人中14例术后发生心肺并发症，其中心律失常4例，心肺并发症病人术前LAA%、Vex/Vin、EI、MLD（ex/in）、Prec1、Prec15均高于未发生心肺并发症病人（P < 0.05）。LAA左肺占比预测发生心肺并发症AUC为0.819，当截断值>32.53%时，敏感性为71.43%，特异性为84.62%。结论随COPD进展，肺过度膨胀会导致心功能降低，CT定量参数与病人心功能、肺功能均具有相关性，可应用于肺功能检测，同时可用于预测肺癌合并COPD病人行肺叶切除术后的心肺并发症发生情况。

Application value of chest CT quantitative technology in assessing cardiopulmonary function in patients with COPD

ObjectiveTo investigate the application value of chest CT quantitative technology in evaluating pulmonary function in patients with chronic obstructive pulmonary disease(COPD).MethodsThe CT parametersincluding the low attenuation area percentage(LAA%), end-expiration lung volume/end-expiration lung volume(Vex/Vin), ratio of end-expiration and end-inspiratory CT average lung density(MLD(ex/in), lowest 1% lung attenuation value(Prec1) and lowest 15% attenuation value(Prec15)], lung function test resultsincluding the total lung capacity(TLC), residual capacity(RV), forced vital capacity(FVC), residual capacity to total lung capacity(RV/TLC), forced expiratory volume and forced vital capacity percentage in 1 second(FEV1/FVC), FEV1 forced expiratory volume in 1 second as a percentage of predicted value(FEV1%)], and cardiac indicatorsincluding the left ventricular ejection fraction(LVEF), left ventricular diameter(LVD), left atrial diameter(LAD), right ventricular diameter(RVD) and right atrial diameter(RAD)] in 95 simple COPD patients with different degrees of illness were detected using chest CT quantitative technology, and compared.Fifty-three lung cancer complicated with COPD patients scheduled by operation were selected, the CT parameters of patients with different conditions of cardiopulmonary complications after operation were compared, and the predictive value of CT parameters to the prognosis of patients was analyzed using the receiver operating characteristic curve.ResultsWith the exacerbation of COPD patients, the total LAA ratio, right lung ratio, left lung ratio, Vex/Vin, EI, MLD (ex/in), Prec1 and Prec15 showed an upward trend, the FVC, FEV1, FEV1% and FEV1/FVC showed a decreasing trend, the RV, TLC and RV/TLC showed an increasing trend, the RVD showed an increasing trend, and the LVEF showed a decreasing trend, and the differences of the above parameters among the patients with different degrees of disease were statistically significant(P < 0.05 to P < 0.01).The LAA%, Vex/Vin, EI, MLD(ex/in), Prec1 and Prec15 were negatively correlated with the FVC, FEV1, FEV1%, FEV1/FVC and LVEF, and positively correlated with the RV, TLC, RV/TLC and RVD(P < 0.05 to P < 0.01).Among the 53 patients, 14 patients with cardiopulmonary complications after surgery(including 4 patients with arrhythmia) were found.The preoperative LAA%, Vex/Vin, EI, MLD(ex/in), Prec1 and Prec15 in patients with cardiopulmonary complications were higher than those in patients without cardiopulmonary complications(P < 0.05).The AUC of proportion of LAA in the left lung in predicting cardiopulmonary complications was 0.819.When the cutoff value was more than 32.53%, the sensitivity and specificity were 71.43% and 84.62%, respectively.ConclusionsWith the progress of COPD, the excessive lung expansion will lead to the cardiac function decreasing.The parameters of CT quantitative technology are closely related to cardiac function and pulmonary function, which can be used to detect lung function and can also be used to predict the occurrence of cardiopulmonary complications in patients with lung cancer complicated with COPD after lobectomy.