面神经与其周围血管相交处的MRI评价指标对面肌痉挛的诊断价值

Diagnostic Value of MRI Evaluation Index of the Intersection of Facial Nerve with Its Surrounding Blood Vessels for Hemifacial Spasm

目的探讨面神经脑池段与其周围血管相交处的评价指标在面肌痉挛时的变化情况及其与面肌痉挛发病率的关系。方法选取采用MRI 3D-FIESTA和3D-TOF序列扫描的单侧面肌痉挛患者70例和检查正常者140例,在多平面重组影像上观测面神经脑池段与其周围血管相交处的血管直径、与脑干距离和面神经周围血管的自身角度、与面神经夹角及其与面肌痉挛发病率之间的关系,组间差异采用配对t检验。结果正常组、面肌痉挛健侧组和面肌痉挛患侧组的相交处血管直径、与脑干距离、血管自身角度、与面神经夹角分别为（0. 48±0. 03） mm、（0. 49±0. 04） mm、（0. 71±0. 06） mm和（8. 69±0. 62） mm、（8. 66±0. 75） mm、（5. 93±0. 47） mm,（74. 39±2. 33）°、（72. 66±2. 54）°、（48. 57±3. 28）°和（85. 60±3. 07）°、（86. 75±2. 73）°、（88. 41±3. 76）°,面肌痉挛患侧组与正常组、面肌痉挛健侧组的相交处血管直径、与脑干距离、血管自身角度均有显著性差异（t=2. 51,t=6. 79,t=8. 65,P 〈0. 05）,与面神经夹角无显著性差异（t=9. 91,P〉 0. 05）,且随着相交处与脑干距离的增加则发病率呈下降趋势,血管直径的增加和血管自身角度的减小则发病率呈上升趋势,与面神经夹角的变化与发病率之间无显著性变化趋势。结论面神经与其周围血管相交处的血管形态学评价指标对诊断面肌痉挛有重要的参考价值,血管的自身角度越小、直径越粗和面神经与血管相交处距离脑干越近,则越易出现面肌痉挛病变。

Objective To investigate the changes of evaluation indexes at intersection of the cisternal segment of facial nerve and its surrounding blood vessels in hemifacial spasm and its relation to the incidence of hemifacial spasm. Methods70 patients with unilateral hemifacial spasm and 140 normal on examination were selected by MRI 3 D-FIESTA and 3 DTOF sequence scanning. The diameter of the vessel at the intersection of the facial cerebral cistern and the surrounding vessels was observed on the MPR reconstructed image. The distance between the self-angle of the blood vessels around the facial nerve,the angle between the facial nerve and the incidence of hemifacial spasm,and the difference between the groups were analyzed by paired t test. Results The vascular diameter to brainstem distance,vascular self angle,to facial nerve angle were（ 0. 48 ± 0. 03） mm,（ 0. 49 ± 0. 04） mm,（ 0. 71 ± 0. 06） mm and（ 8. 69 ± 0. 62） mm,（ 8. 66 ± 0. 75） mm,（ 5. 93 ± 0. 47） mm and（ 74. 39 ± 2. 33） °,（ 72. 66 ± 2. 54） °,（ 48. 57 ± 3. 28） ° and（ 85. 60 ± 3. 07） °,（ 86. 75 ±2. 73） °,（ 88. 41 ± 3. 76） ° on the normal group,uninjured group of hemifacial spasm and ipsilateral group of hemifacial spasm respectively. There were significant differences between the ipsilateral group of hemifacial spasm to the normal group,uninjured group of hemifacial spasm at the vascular diameter,to brainstem distance,vascular self angle（ t = 2. 51、t = 6. 79、t = 8. 65,P〈0. 05）,there was no significant difference to facial nerve angle（ t = 9. 91,P〉0. 05）. The increase to brainstem distance with the morbidity decreased,the morbidity increases with the increase of vascular diameter and the decrease of vascular self angle,there was no significant change between the facial nerve angle to morbidity. Conclusion It was important for vascular morphology to evaluate the facial nerve and its peripheral vessels to diagnose hemifacial spasm. The smaller the vascular self angle,the thicker the vascular diameter and the nearer the intersection to the brainstem,the more prone to hemifacial spasm lesions.