幼儿气管支气管异物低剂量MSCT重组成像的诊断价值

Value of Low-dose Multi-slice CT with Post-processing Techniques in the Diagnosis of Endo-tracheal/Bronchial Foreign Bodies of Children

目的:探讨64层螺旋CT低剂量扫描重组成像对幼儿气管支气管异物的诊断价值。方法:36例临床怀疑气管支气管异物并行低剂量螺旋CT扫描的幼儿,记录每位患儿的平均有效剂量(mGy);将容积数据进行多平面重组(MPR)、最小密度投影(MinIP)和仿真支气管镜(VB)成像,32例MSCT检查证实或高度怀疑异物者后24h内行硬支气管镜检查;并将两者结果进行对比,评价MSCT诊断的优势及局限性。结果:硬支气管镜证实气管支气管异物32例,MSCT均得到准确诊断,异物位于右主支气管16例,左主支气管10例,中间段支气管3例,叶支气管2例,双侧支气管1例,MSCT与传统支气管镜检查结果一致,32例异物并发肺气肿24例,阻塞性肺炎18例,肺不张4例;图像质量好的25例(69.4%),符合诊断要求的7例(19.2%),不能达到诊断要求的4例(11.4%);MPR与MinIP、VB间比较有统计学差异(P<0.05),MinIP与VB间无统计学差异(P>0.05),MPR能多角度清晰显示段以上气管支气管异物并能显示肺部并发症,优于其它两者,可弥补横断面图像的不足。结论:幼儿气管支气管异物MSCT低剂量扫描能满足诊断,准确评估异物大小、位置、形态及肺部并发症,能减少不必要的支气管镜检查及弥补X线胸片的不足。

Objective：To evaluate the value of low dose multi-slice CT （MSCT） with post-processing techniques in the diagnosis of endo-tracheal / bronchial foreign bodies in children. Methods：36 pediatric patients with clinically suspected endo tracheal / bronchial foreign bodies underwent low-dose MSCT scanning. The mean effective dosage of radiation （mGy） was measured for all patients. Post processing techniques including multiplanar reformation （MPR）, minimum intensity projection （MinlP） and virtual bronchoscopy （VB） were performed. All of the 32 patients underwent rigid bronchoscopy within 24h after endo-tracheal / bronchial foreign bodies were proved or highly suspected by MSCT. MSCT findings were retrospectively correlated with that of rigid bronchoscopy. The advantages and disadvantages of MSCT in the diagnosis of endotracheal / bronchial foreign bodies were evaluated. Results： Of the 32 pediatric patients, all foreign bodies detected by con ventional bronchoscopy were also revealed on MSCT. The location of foreign bodies were in the right main bronchus （16 pa tients） ,left main bronchus （10 patients）,bronchus intermedius （3 patients）,lobar bronchus （2 patients） and bilateral bronchi （1 patient）. No discordance was found between the two techniques. Pulmonary complications included emphysema （24 patients） ,obstructive pneumonia （18 patients） and atelectasis （4 patients）. The imaging quality was excellent in 25 pa tients,（69.4%）, sufficient for diagnosis in 7 patients,（19.2%） and poor,insufficient for diagnosis （4 patients,11.4%）. There were statistical differences for the capability of diagnosis between MPR with MinlP and VB （P〈0.05） ,no statistical difference was existed between MinIP and VB （P〉0.05）. MPR could clearly demonstrate foreign bodies located above seg mental bronchi on multiple planes,as well as pulmonary complications,which was superior to MinlP and VB; and the shortage of axial images could be made up. Conclusion： Low dose MSCT with post-processing techniques is satisfactory in the diagnosis of endo-tracheal /bronchial foreign bodies in children, the exact size,location, shape of foreign bodies as well as pulmonary complications could be accurately evaluated, unnecessary bronchoscopy could be avoided and the shortcoming of chest radiography could be made up.