1.5T场强下3D高分辨率磁共振臂丛神经成像的应用价值研究

The Exploration and Application on 3D High-Resolution MR Brachial Plexus in 1.5 T Field

目的探讨1.5 T场强下,重T2加权3D T2-SPACE-STIR序列在臂丛神经走行、分布、与周围组织的对比以及相关疾病诊断的临床应用价值。方法连续随机搜集2016年5月至2017年10月临床可疑臂丛神经疾病的患者共85例,按照检查时间先后顺序随机分成两组,分别在3.0 T(Trio,Siemens,Erlangen,Germany),1.5 T(Aera,Siemens,Erlangen,Germany)下行增强后重T2加权3D T2-SPACE-STIR序列扫描。对两种场强下所得臂丛神经图像的显示及伪影进行评价分析并采用五分法进行评分(1分,神经结构不可见;2分,神经结构可见,但不可分析评价;3分,神经结构可见,但走行不连续,边界欠清或有严重背景干扰;4分,神经主干结构可辩,对比良好;5分,神经全程结构清晰,走行及边界清楚,对比良好),测量特征点信噪比(SNR),对比噪声比(CNR),计算神经和背景组织相对比值(CR),观察臂丛神经相关性疾病在该序列中的MR表现。结果3.0 T场强下所得臂丛神经图像得分较高(3.0 T,18.3±1.2;1.5 T,14.5±1.1),两种场强下臂丛神经显示情况均可以满足临床需求(>12分);图像伪影评分1.5 T场强(4.1±0.7)高于3.0 T(2.9±1.4),两者差异具有统计学意义(P<0.001);3.0 T场强下的SNR与CNR比1.5 T高,1.5 T场强下各对比组CR值均高于3.0 T(除小静脉外)。结论1.5 T场强下重T2加权3D T2-SPACE-STIR序列臂丛神经成像可以满足临床上臂丛神经疾病的诊断需求,且在抑制因抑脂不均导致的图像伪影情况上要优于3.0 T,说明1.5 T图像在显示臂丛神经及分支与背景各组织间的差异性更好,1.5 T下臂丛神经成像有其独到的优势。

Objective To explore the clinical application value of heavy T2-weighted 3 D T2-SPACE-STIR sequence in the course and distribution of brachial plexus,comparison with surrounding tissues,and diagnosis of related diseases under 1.5 T field strength.Methods A total of 85 patients with clinically suspected brachial plexus disease from May 2016 to October 2017 were continuously and randomly collected.They were randomly divided into 2 groups according to the order of examination time,at 3.0 T(Trio,Siemens,Erlangen,Germany),1.5 T(Aera,Siemens,Erlangen,Germany)downlink enhanced heavy T2-weighted 3 D T2-SPACE-STIR sequence scanning.Evaluate and analyze the display and artifacts of brachial plexus images obtained under two field strengths and use the five-point method to score(1 point,nerve structure invisible;2 points,nerve structure visible,but not analytically evaluated;3 points,Neural structure is visible,but the course is discontinuous,the boundary is not clear or there is serious background interference;4 points,the neural backbone structure is discernible,and the contrast is good;5 points,the nerve structure is clear throughout the course,the course and boundary are clear,and the contrast is good.).We measurement Point signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),calculate the relative ratio(CR)of nerve and background tissue,and observe the MR performance of brachial plexus-related diseases in the sequence.Results(1)The brachial plexus images with 3.0 T field strength were higher(3.0 T,18.3±1.2),(1.5 T,14.5±1.1),and the two kinds of field intensity imaging were able to meet the clinical requirement(greater than 12 points),(2)the image artifact scores(4.1±0.7,1.5 T)were higher(2.9±1.4,3.0 T)(P<0.001),and the difference was statistically significant;(3)the SNR at 3.0 T field strength was higher than that of CNR at 1.5 T,and the CR values of each group at 1.5 T were higher than that of 3.0 T(except for small veins).Conclusion The results showed that under 1.5 T field intensity,3 D T2-SPACE-STIR series brachial plexus imaging,could meet the needs of diagnosis of upper brachial plexus disease,and it was better than 3.0 T in suppression of image artifacts caused by lipid suppression.The difference between tissues under 1.5 T is better.1.5 T plexus neuroimaging has its unique advantages.