磁敏感加权成像对帕金森病患者丘脑底核的显示价值初探

Improved visibility of the subthalamic nucleus in PD patients using susceptibility-weighted imaging: a preliminary study

目的评价磁敏感加权成像(susceptibility-weighted imaging,SWI)对帕金森病(Parkinson's disease,PD)患者丘脑底核(subthalamic nucleus,STN)的显示价值。方法收集帕金森病患者20例,所有患者接受3.0T MR检查,扫描序列包括磁敏感加权序列(SWI)、FSE-T2WI和3D-TIWI序列,由富有经验的影像医师对图像质量进行评分,根据STN与周围组织间的信号对比及边界的清晰度两方面,共分0、1、2、3级四个等级,比较SWI、FSE-T2WI和T1WI三种不同序列对STN的显示。结果在SWI序列,18/20例(90%)患者丘脑底核显示为2～3级,呈双凸透镜形低信号,边界清晰。在T2WI像,20例中4例(20%)显示为0级,无法分辨;13例(65%)显示为1级,低信号依稀能分辨,但对比较差;仅3例(15%)2～3级,显示较为清楚、易于分辨。在T1WI像,绝大多数(18/20,90%)病例STN显示为0级,无法分辨;只有2例(10%)1级,形态结构依稀可见。经秩和检验,三组间对STN的显示质量存在显著差异,两两比较T1WI和T2WI,T2WI和SWI组间也存在显著差异。结论相比常规T2WI和T1WI,磁敏感加权成像明显提高了对丘脑底核的显示能力,在脑深部刺激术丘脑底核的精确定位中将具有广阔的应用前景。

Objective： To evaluate the visibility of the subthalamic nucleus （STN） using susceptibility-weighted imaging （SWI） for Parkinson＇s disease （PD）. Materials and Methods： Twenty PD patients were collected and examined with MRI to visualize the STN. Scanning protocols included SWI, T2-weighted fast spin-echo images （FSE） in axial and coronal plane and high-resolution T1WI images in axial plane. According to the signal contrast and border sharpness between STN and structures, the images were classified to four grades （grade 0, 1, 2, 3） by experienced radiologist. The visibility of STN was evaluated in the three protocols. Results： In SWI images, the STNs of 18 cases （90%） were classified to grade 2-3 which clearly visualized as hypointense, biconvex lens-shaped structure. In T2WI images, the STNs of 4 cases （20%） couldn＇t be identified as grade 0. Thirteen cases （65%） showed hypointense but poor contrast as grade 1, only 3 cases （15%） were clearly visualized as grade 2-3. In T1WI images, the STNs of 18 cases （90%） couldn＇t be identified as grade 0. Only 2 cases （10%） showed but poor contrast as grade 1. Significant difference was found among three protocols. Significant differences were found between T1WI and T2WI, T2WI and SWI. Conclusion： Compared to T1WI and T2WI, SWI improves the visibility of the STN. It may be a promising technique to accurately localizes the STN for precise surgical targeting.