MRI自动定位技术在脑转移瘤中的应用

Performance of Brain MR with On-line Automatic Slice Positioning in Metastatic Brain Tumors

目的:评估MRI自动定位技术用于检测脑转移瘤的诊断效能,并与传统的手动定位方法进行比较.方法:连续性纳入32例确诊的脑转移瘤患者,他们均在2种不同的MRI扫描仪上进行颅脑增强MRI检查,即配备颅脑自动定位技术的Siemens Aera(1.5 T)扫描仪和传统手工定位的GE 750 W扫描仪(3.0 T).将Siemens Aera和GE 750 W扫描仪获得的颅脑增强MRI图像分别设为A组和B组.计算2组的诊断效能和诊断信心.结果:对于A组,脑转移瘤阳性数目的诊断灵敏度为87.4%(153/175),对照既往的MRI增强检查后,A组的诊断灵敏度提高到98.3%(172/175),且差异具有统计学意义(P<0.05).对于B组,相应的诊断灵敏度分别为88.9%(112/126)和99.2%(125/126),同样差异具有统计学意义(P<0.05).A组和B组之间的诊断灵敏度差异无统计学意义(P>0.05).A组和B组的平均诊断置信度分别为3.9和3.8(P>0.05).结论:本研究初步表明参照既往影像检查可以提高检测脑转移瘤的诊断灵敏度.MRI自动定位技术有助于快速发现病变,并且与传统手动定位方法相比,这种技术不会牺牲诊断灵敏度和诊断信心.

Purpose:To evaluate the diagnostic accuracy for detecting the metastatic brain tumors using MRI with automatic slice positioning technique,and to compare with the conventional manually positioning manner.Methods:A total of 32 patients with metastatic brain tumors were enrolled in this study.All patients underwent contrast-enhanced MRI examinations on two different MR scanners,1.5 T MR system with automatic slice positioning technique and 3.0T system without auto-positioning technique.Images acquired in the scanner with and without auto-positioning were divided into group A and B,respectively.The diagnostic sensitivity and confidence of the two groups was recorded.Result:In group A,the diagnostic sensitivity for the number of metastatic brain tumors was 87.4%(153/175),if attentions were only paid on the latest scan.After referring to initial images,the diagnostic sensitivity in group A was raised to 98.3%(172/175),and the difference was with statistical significance(P<0.05).In group B,the corresponding diagnostic sensitivities were 88.9%(112/126)and 99.2%(125/126),respectively;and the difference was with statistical significance(P<0.05).The diagnostic sensitivities of group A and B were with no significant difference(P>0.05).The average degree of diagnostic confidence in group A and B was 3.9 and 3.8,respectively,with no significant difference(P>0.05).Conclusion:According to this preliminary study,referring to initial imaging can raise the diagnostic sensitivity for detecting the development of metastatic brain tumors.Automatic slice positioning does help in finding lesions and such technique does not sacrifice the diagnostic sensitivity and the diagnostic confidence when comparing with the conventional manually positioning method for brain tumor.