多层螺旋CT低剂量扫描筛查及定性诊断肺微小结节的临床应用  

Clinical application of low dose multi-slice spiral CT scan in detection of pulmonary micronodules

作　　者：江一峰[1] 叶剑定[1] 陈群慧[1] 沈艳[1] 

机构地区：[1]上海交通大学附属胸科医院放射科,上海200030

出　　处：《诊断学理论与实践》2010年第2期141-145,共5页Journal of Diagnostics Concepts & Practice

摘　　要：目的:评估多层螺旋CT胸部低剂量扫描检测肺微小结节的灵敏度及显示结节征象的能力,探讨最优的扫描参数。方法:在模型预扫描的基础上,对200例行常规CT检查发现肺微小结节(直径≤15mm)的研究对象行64层螺旋CT小范围低剂量(30mAs和21mAs)扫描,分析不同扫描剂量对结节分叶、毛刺、钙化、空泡和支气管征、密度不均匀、胸膜凹陷等征象的显示情况及结节直径测量的准确性。结果:30mAs扫描可检出模型及研究对象所有的肺结节[最小直径为3mm的磨玻璃样阴影(GGO)],在显示结节内部、边缘征象及大小测量的准确性方面与常规剂量影像无明显差异(P>0.05)。在200例研究对象中,采用21mAs扫描无法显示1例4mmGGO,且显示结节的毛刺征欠佳。低剂量扫描测量的肺结节直径与常规剂量扫描所得直径间差异无统计学意义(P>0.05)。结论:临床上使用64层螺旋CT低剂量扫描对肺小结节进行筛查、初步鉴别诊断和随访是可行的,提示30mAs是优选的低剂量扫描参数。Objective To evaluate the sensitivity of low dose multislice spiral CT scanning in detection of pulmonary micronodules and the ability of showing the signs of these nodules,and to appraise the optimal scanning parameter. Methods Based on preliminary scan of a chest phantom,200 patients with pulmonary micronodules （≤ 15 mm） detected by routine CT examination were scanned with 64-slice spiral CT on small range and low dose （30 mAs and 21 mAs）. Analyzed the display of signs of nodules by various scanning dosages,including lobulation,spiculation,calcification,cavitation,bronchus sign,inhomogeneous density,and pleural indentation,and the accuracy of measurement of the diameter of nodules. Results All the nodules [minimal：3 mm,GGO （ground glass opacity）] could be detected by 30 mAs scanning,there was no statistical significance （P〉0.05） in showing interior or border signs between 250 and 30 mAs scanning （P〉0.05）,while the 21 mAs scanning failed to detect a 4 mm GGO nodule,and showed less spiculation signs. The size of the nodules measured by low dose and conventional dose scanning was of no statistical difference （P 〉0.05）. Conclusions Sixty-four slice spiral CT low-dose scanning can be clinically used for screening,preliminary differential diagnosis,and follow-up of pulmonary micronodules. 30 mAs is the optimal low dose scanning parameter.

关 键 词：肺结节 辐射剂量 X线计算机体层摄影术 

分 类 号：R814.4[医药卫生—影像医学与核医学]