利用定量CT评估淋巴管平滑肌瘤病的肺部损害

Usage of quantitative CT in evaluating the degree of lung destruction in lymphangioleiomyomatosis

目的量化CT影像中肺部囊性损害的程度,并比较其与肺功能结果和血清血管内皮生长因子(vascular endothelial growth factor,VEGF-D)水平的相关性,探究定量CT评估淋巴管平滑肌瘤病(lymphangioleiomyomatosis,LAM)肺部损伤和指导LAM治疗的能力。方法通过人工智能软件识别肺部CT影像中的囊性区域,计算其在总肺中所占的体积百分比,即囊泡评分。本研究共纳入21例受试者,研究36次CT囊泡评分和肺功能的相关性。对其中17例受试者计算24次CT囊泡评分和血清VEGF-D水平相关性。通过计算CT囊泡评分评估肺功能的ROC曲线,探究囊泡评分预测肺损伤的能力。结果囊泡评分与第1秒用力肺活量占预计值百分比(percentage of predicted forced of expiratory volume in one second,FEV1%pred)(r=-0.716,P<0.001)和一氧化碳弥散量占预计值的百分比(percentage of predicted diffusing capacity of the lungs for carbon monoxide corrected for alveolar volume,DLCO/VA%pred)(r=-0.821,P<0.0001)显著相关,与血清VEGF-D水平的相关性不明显(r=-0.143,P=0.506)。当囊泡评分为15.80%时,预测肺功能受损的约登指数最高(0.667),预测肺功能损伤的灵敏度和特异度分别为94.44%和72.22%。结论肺CT囊泡评分与FEV1%pred和DLCO/VA%pred显著相关,但是与血清VEGF-D水平的相关性不明显。囊泡评分>15.80%时提示肺功能损害明显,建议患者接受西罗莫司治疗。

Objective To quantify the degree of pulmonary cystic damage in CT and compare its correlation with pulmonary function tests(PFTs)and serum levels of vascular endothelial growth factor(VEGF-D),and to study the potential of quantitative CT to assess the degree of lung damage and decide treatment in lymphangioleiomyomatosis(LAM).Methods Pulmonary cystic areas in CT images were identified by the artificial intelligence software.The volumetric percentage of cystic regions of the total lung volume was calculated to get a cyst score.The association between the 36 times of CT scan and PFTs were analyzed in 21 patients.The correlation of serum VEGF-D levels of 17 patients and their 24 times of CT scan were studied.A ROC curve was calculated to select the threshold at which the cyst scores could predict the lung impairment best.Results Cyst scores correlated significantly with percentage of predicted forced of expiratory volume in one second(FEV1%pred)(r=-0.72,P<0.001)and percentage of predicted diffusion capacity(DLCO/VA%pred)(r=-0.821,P<0.0001),while its correlation with serum VEGF-D levels(r=-0.143,P=0.506)was not obvious.The Youden index is max(0.667)with a 94.44%sensitivity and a 72.22%specificity when cyst score is 15.80%.Conclusion Pulmonary cyst scores on CT is strongly correlated with FEV1%pred and DLCO/VA%pred.However,the association with serum levels of VEGF-D is not obvious.Cyst score>15.80%might indicate an abnormal lung function and patients are recommended a sirolimus treatment.