创伤性臂丛神经损伤的磁共振成像3D-FIESTA-C、IDEAL序列特征及诊断价值

目的：探讨创伤性臂丛神经损伤的磁共振成像（MRI）三维循环相位稳态采集快速成像（three-dimensional fast imaging employing steady state acquisition with cycled phases,3D-FIESTA-C）序列和三点法非对称回波水脂分离成像（iterative decomposition of water and fat with echo asymmetry and least squares estimation,IDEAL）序列特征及诊断价值。方法：对32例创伤性臂丛神经损伤患者进行术前MRI 3D-FIESTA-C及IDEAL序列检查后,再行图像后处理及诊断,总结臂丛神经损伤的MRI特征,将诊断结果与手术探查结果进行比较,评价术前MRI 3D-FIESTA-C联合IDEAL序列检查在诊断臂丛神经损伤中的作用。结果：12例患者术后证实共有39条节前神经损伤,3D-FIESTA-C序列显示出38条,其中31条神经根影像提示消失或离断,7条神经根丝减少、迂曲,无法连续追踪至椎间孔,同时可伴有神经根袖变钝、脊膜囊肿形成、硬脊膜增厚及脊髓形态信号异常改变。术前MRI 3D-FIESTA-C序列诊断臂丛神经节前损伤的灵敏度为97.5%,特异度为100%,准确率达98.3%。31例120条节后损伤中共12例45条节后神经断裂,其中7条伴纤维瘤形成,IDEAL序列显示42条节后神经根断裂,其他损伤表现为神经增粗,扭曲,走行僵直,周围结构水肿紊乱等。术前IDEAL序列诊断臂丛节后损伤的灵敏度为96.7%,特异度为100%,准确率为97.1%。结论：MRI 3D-FIESTA-C联合IDEAL序列检查可清晰显示节前及节后臂丛神经损伤情况,对臂丛神经损伤的诊断符合率较高,可作为临床首选的无创性影像学方法。

The features and diagnostic value of 3D-FIESTA-C and IDEAL sequences for brachial plexus injury

0bjective: To study the features and diagnostic value of MRI 3D-FIESTA-C (three-dimensional fast imaging employing steady state acquisition with cycled phases) and IDEAL (iterative decomposition of water and fat with echo asymmetry and least squares estimation）for traumatic brachial plexus injury. Methods: Thirty-two cases of traumatic brachial plexus injury were examined by MRI 3D-FIESTA-C and IDEAL sequences before operation. The imaging data were treated with post processing imaging. The diagnostic results were compared with the findings in operation. The value of MRI 3D-FIESTA-C and IDEAL sequences for diagnosing traumatic brachial plexus injury before operation was evaluated. Results: It revealed postoperatively that preganglionic brachial plexus injury occurred in 12 cases (39 nerves). The features of preganglionic brachial plexus injury in MRI 3D-FIESTA-C sequence included disappearance or disruption of nerve root(31), and decrease of nerve root filaments(7) with nerve root sleeve abnormality, meningeal cyst, sheath thickening and abnormal spinal cord signal. Compared with the findings in surgery, the sensitivity, specificity and accuracy of 3D-FIESTA-C sequence in diagnosing preganglionic brachial plexus injury were 97.5%, 100%, 98.3%, respectively. Postganglionic injury occurred in 31 cases (45 nerves), IDEAL sequence showed continuity interruption(42), and the others showed nerve trunk enlargement, distortion, rigidity, adjacent structure disorder and edema. Compared with the finding in surgery, the sensitivity, specificity and accuracy of IDEAL sequence in diagnosing postganglionic injury were 96.7%, 100%, 97.1%, respectively. Conclusions: MRI 3D-FIESTA-C and IDEAL sequences are excellent in revealing preganglionic brachial plexus injury and postganglionic injury. Their diagnosis accuracy rates are high. MRI is non-invasive and optimal for clinical diagnosis.