CT肺坠积效应与气道阻力关系的初步研究  

Relationship between hypostasis effect in the lung parenchyma on CT and small airway resistance ： a preliminary study

作　　者：南喜文[1] 唐光健[2] 彭泰松[1] 许志高[1] 徐建国[1] 李东春[1] 高永莉[1] 郝宝堂 高立伟[3] 陈玉花[3] 刘亮[4] 

机构地区：[1]山西省大同市第三人民医院放射科,037008 [2]北京大学第一医院放射科 [3]山西省大同市第三人民医院呼吸内科,037008 [4]大同市阳高县人民医院放射科

出　　处：《中华放射学杂志》2015年第3期183-185,共3页Chinese Journal of Radiology

摘　　要：目的 探讨CT肺坠积效应（HELC）与肺气道阻力改变的相关性.方法 2012年7月至2013年9月选取48例常规CT显示无肺气肿、炎症、弥漫性肺间质纤维化,无胸部手术史,无心功能不全,可耐受肺功能检测患者及志愿者纳入研究.所有受试者均先仰卧位、平静呼吸下于主动脉弓、支气管隆突下及膈顶水平分别扫描3层（层厚5 mm）后,再俯卧位平静呼吸下相同层面扫描3层,重建层厚1.25 mm.CT扫描后2d内行肺功能检查.以用力呼气第1秒呼气量与用力肺活量比（FEV1.0/FVC％）（实/预）为金标准,将受试者分为2组,A组：FEV1JFVC％（实/预）≥80％,B组：FEV1.0FVC％（实/预）＜80％两组.2名高年资放射医师盲法于PACS上阅读影像,以仰卧位CT影像背侧胸膜下新月形磨玻璃样密度改变,俯卧位消失为有坠积效应.采用x2检验比较2组受试者坠积效应出现率的差异,以P＜0.05为差异有统计学意义.结果 A组33例,FEV1JFVC％（实/预）为80.4％～105.2％,平均（92.0±7.5）％,坠积效应出现24例（66.7％）;B组15例,FEV10/FVC％（实/预）为46.6％～78.0％,平均（63.4±10.0）％,坠积效应出现2例（13.3％）;2组间差异具有统计学意义（x2=14.653,P＜0.01）.结论 气道阻力增加时HELC出现率降低,平静呼吸时CT未显示坠积效应可能反映了气道内气流受限,这可能对慢性阻塞性肺病（COPD）的诊断有提示作用.Objective To investigate the correlation between hypostasis effect in the lung parenchyma on CT （HELC） and small airway resistance.Methods Forty-two consecutive patients and 6 volunteers without parenchyma pathologic change on CT or history of chest operation were enrolled in the study,which was approved by the hospital institution,and informed consent was obtained.CT scans of 3 slices with thickness 5 mm were performed at the levels of aorta arch,sub-bronchial carina and diaphragmatic dome in both supine and prone positions with smooth breathing and reconstruction of 1.25 mm.CT and pulmonary function test （PFT） studies were performed within 2 days.Patients were divided into two groups according to the ratio of the forced expiratory volume in 1 s and the forced vital capacity of predict％ （FEV1.0/FVC％） as gold standard：group A （normal small airway resistance,SAR） with FEV1.0/FVC％ ≥ 80％,and group B：（abnormal SAR） with FEV1.0/FVC％＜ 80％.Two senior radiologists blinded to PFT results reviewed CT images from PACS with consensus to identify and document hypostasis effect,defined as crescent-shaped ground glass in the dorsal subpleural lung parenchyma in supine and disappeared in prone position,shown in CT images.The number and frequency of cases with hypostasis effect on CT between the two groups were compared statistically with Chi square test.Result Thirty-three cases were in group A with FEV1/FVC of 92.0％±7.5％ （80.4％ to 105.2％）,and 24 cases of them （66.7％） showed hypostasis effect on CT scans; 15 cases were in group B with FEV1.0/FVC％ of 63.4％±10.0％ （46.6％ to 78.0％）,and only 2 cases （13.3％） demonstrated hypostasis effect （x2=14.653,P＜0.01）.Conclusions The rate of HELC appearance decreases with increasing of small airway resistance.Lack of hypostasis effect in lung CT imaging with smooth breathing during CT scan may reflect increased intra pulmonary pressure caused by airflow limitation,and may be used as a new indicator of COPD.

关 键 词：气道阻力 肺通气 体层摄影术 X线计算机 

分 类 号：R816.4[医药卫生—放射医学]