低剂量呼气相肺重建 CT评价肺小气道病变的价值

摘要

To investigate clinical value of low dose of expiratory CT reconstruction in evalu-ation of pulmonary small airway disease .Method:80 patients with pulmonary small airway disease were se-lected in our hospital from October 2011 to December 2013,who were randomly divided into 4 groups.Each group with 20 patients,who were given different current(200mA;100mA;50mA;25mA) and fixed tube volt-age 100kV.Patients underuent expiratory lung spiral CT scanning and pulmonary function detection .Two kinds of examination results were analyzed .Subjective scoring of vascular clearly degree used blind method . SNR of images and X-ray dose were analyzed .Result:Multiple parameters of PFT detection had obvious rel-evance with LAA%in 25mA group.Expiratory LV had high relevance with FEV 1 in 200mA group.Accord-ing to sequence of 200mA,100mA,50mA,25 mA,B1,B2,V, SNR of images,X-ray dose decreased signifi-cantly.There's statistically significant differences were ( P<0.05) .In signs of frequency , air retention rate was the highest , followed by ground glass opacity; centrilobular emphysema , pulmonary bulla , pulmonary parenchymal micronodules , hypostaticeffect , interlobular septal lines , paraseptal emphysema .Conclusion:Scanning conditions of tube current 50mA and tube voltage100kV can obtained image quality in diagnosis and significantly decrease effective radiation dose ,which can be used in CT assessment of pulmonarysmall airway disease .%探讨低剂量呼气相肺重建CT 评价肺小气道病变的临床价值。方法：选取本院2011年10月至2013年12月诊治的肺小气道病变患者80例，采用数字随机法分为4组，每组20例，分别给予不同的电流（200mA、100mA、50mA、25mA），管电压固定在100kV，行呼气相全肺螺旋CT 扫描，同时检测患者的肺功能，分析两种检查结果的相关性，采用盲法对血管清晰程度行主观评分，分析图像信噪比和X 线有效剂量。结果：25mA 组LAA％与PFT 检测中的多个参数具有明显的相关性，200mA 组呼气相LV 与FEV1具有高度相关性。依200mA、100mA、50mA、25mA 顺序，B1、B2、V、图像信噪比、X 线有效剂量均呈现出明显的下降趋势，相互间比较，差异均有统计学意义（P＜0．05）。各征象的出现频率上，空气潴留的出现率最高，其次为磨玻璃样密度影、小叶中心肺气肿、肺大泡、肺实质微结节、坠积效应、小叶间隔线和间隔旁气肿。结论：采用管电流50mA 和管电压100kV 的扫描条件，不仅可以获得可供诊断需要的图像质量，同时明显降低了有效辐射剂量，可用于对肺小气道病变的CT评价。