MR三维神经鞘信号增高并背景抑制弛豫增强的快速采集成像序列在节后臂丛神经显示及临床应用的初步探讨

The optimal visualization of brachial plexus with utilization of nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation imaging MR neurography and initial dignostic application

目的：研究三维神经鞘信号增高并背景抑制弛豫增强的快速采集成像（3D SHINKEI）序列，在显示节后臂丛神经及其病变的优势及临床价值。方法24名健康志愿者及46例经手术病理或临床随访证实的节后臂丛神经病变患者，行3.0 T MR成像。扫描序列包括3D SHINKEI、短TI反转恢复序列（STIR）及扩散加权MR神经成像（DW-MRN）。对24名志愿者SHINKE及DW-MRN图像臂丛神经的显示情况进行评分，并测算3D SHINKEI、STIR图像的对比噪声比（CNR）。比较3D SHINKEI与STIR序列在节后臂丛神经损伤组的病变检出率。2名阅片者对24名志愿者SHINKE及DW-MRN图像评分情况进行Kappa一致性检验，对3D SHINKEI及DW-MRN图像评分进行Mann-Whitney秩和检验；对3D SHINKEI、STIR图像的CNR进行两独立样本t检验；3D SHINKEI与STIR序列在检出节后臂丛神经损伤组病变的阳性检出率采用xˉ± s检验进行分析。结果2名阅片者对24名健康志愿者双侧节后臂丛神经的评分在3D SHINKEI序列分别为（3.6±0.6）、（3.5±0.6）分，Kappa值0.8；在DW-MRN序列上分别为（3.0±0.2）、（2.9±0.1）分，Kappa值0.6。2名医师的评分结果一致性良好，对3D SHINKEI序列图像的评分高于DW-MRN序列,两种序列的结果差异有统计学意义（Z=2.667, P值均〈0.05）。3D SHINKEI及STIR序列的CNR分别为0.61±0.07，0.42±0.03，3D SHINKEI序列的CNR高于STIR序列，两者差异有统计学意义（t=12.78, P〈0.05）。3D SHINKEI及STIR序列对46例节后臂丛神经病变患者的检出率分别为78.3%、52.2%（χ2=9.421，P〈0.05）。结论3D SHINKEI序列较DW-MRN、STIR序列有更高的分辨率及CNR，能更为清晰地显示节后臂丛神经解剖结构及其病变。

Objective To assess the optimal visiualization capacity of brachial plexus with three-dimensional nerve-sheath signal increased with inked rest-tissue rapid acquisition of relaxation imaging （3D SHINKEI）, exploring the feasibility of preliminary diagnostic value on brachial plexus diseases. Methods MRI scans were performed on 24 healthy volunteers with no history of brachial plexus injury, and 46 patients whose outcomes of lesions had been verified as post-ganglionic brachial plexus injuries by surgery or clinical follows-up . The scan series consist 3D SHINKEI, STIR in the coronal plane as well as DW-MRN in the axial plane using a 3.0 T MR system. The source and post-processed images of 3D＆amp;nbsp;SHINKEI and DW-MRN were scored according to the optimal visibility on brachial plexus, in the meanwhile, contrast-to-noise ratio of the original images in the 3D SHINKEI and STIR sequences were calculated separately. Two radiologists blindly compared the detection rate of positive brachial plexus injuries between 3D SHINKEI and STIR in 46 patients. And then analyze the outcomes by means of Kappa test, Mann-Whitney test , independent sample t test, and Chi-square test. Results Post-ganglionic brachial plexus showed high intensity in the 3D SHINKEI sequence. In the 24 healthy volunteers, the scores by the two radiologists were 3.6 ± 0.6, 3.5 ± 0.6, 3.0 ± 0.2, 2.9 ± 0.1, respectively. There was statistical difference between the two sequences （Z=2.667,P=0.008,〈0.05）. And the Kappa was 0.8 and 0.6 with favorable consistency. The CNR of 3D SHINKEI and STIR were 0.61 ± 0.07, 0.42 ± 0.03 （t=12.78, P=0.001, 〈0.05）. The positive detection rates of post-ganglionic brachial plexus injuries on 3D SKINKEI and STIR were, 78.3%, 52.2%（χ2=9.421, 〈0.05）. Conclusions 3D SHINKEI sequence demonstrates robust visibility consistently and can clearly display the structures and signals of post-ganglionic abnormality, compared with DW-MRN and STIR. This technique can be helpful to provide more complementary information to further confirm the diagnosis of brachial plexus injuries.