MRI增强3D FLASH联合3D CISS评估原发性三叉神经痛三叉神经形态学改变及与疼痛程度相关性

The assessment of morphological changes of the trigeminal nerves in primary trigeminal neuralgia and its correlation with the extent of pain by the contrast-enhanced 3D FLASH and 3D CISS sequences

目的:探讨MRI增强三维快速小角度激发(3DFLASH)序列联合三维稳态构成干扰(3DCISS)序列在原发性三叉神经痛(TN)三叉神经形态学改变及与疼痛程度相关性研究中的应用价值。方法:回顾性分析单侧48例原发性TN患者MRI影像,采用高分辨率MRI扫描,测量三叉神经脑池段长度及面积、三叉神经脑桥角及桥小脑角池截面积。将血管神经压迫程度进行分级:1级为无接触;2级为接触或可疑接触;3级为压迫。应用VAS评分进行疼痛程度评分,并评估血管神经压迫程度与VAS评分的相关性。结果:患侧三叉神经脑池段血管1级8例,2级28例,3级12例;患侧三叉神经脑池段长度为(9.17±3.30)mm,健侧长度为(9.53±2.50)mm,两者比较差异无统计学意义(P>0.05);患侧三叉神经脑池段面积为(19.78±6.95)mm^2,健侧面积为(26.37±13.20)mm^2,两者比较差异有统计学意义(P<0.05);患侧三叉神经脑桥角为40.02°±14.43°,健侧角度为52.57°±16.10°,两者比较差异有统计学意义(P<0.05);患侧桥小脑角截面积为(191.75±68.75)mm^2,健侧面积为(236.74±64.79)mm^2,两者比较差异有统计学意义(P<0.05)。血管神经压迫程度与VAS评分具有相关性(r=0.309,P=0.033)。结论:MRI增强3DFLASH联合3DCISS序列对原发性TN患者三叉神经形态学改变能定性、定量地诊断;三叉神经脑桥角锐利、桥小脑角池的狭小易导致神经血管冲突,血管神经压迫程度与VAS评分具有相关性。

Objective： To assess the morphologic changes in the primary trigeminal neuralgia with the high-resolution MR imaging, and to evaluate the correlation between the degrees of neurovascular compression and the extent of pain. Methods： Forty-eight patients with trigeminal neuralgia undergoing the enhanced three-dimensional fast low angle shot （3D-FLASH） and three-dimensional constructive interference in steady-state （3D-CISS） sequence were retrospectively analyzed. The length and area of the cisternal segment of the trigeminal nerve, the trigeminal-pontine angle and the cross-sectional area of cerebellopontine angle cistern were measured. The vascular compression was classified into three degrees： degree I, no contact; degree II, contact or suspicious; degree III, compression. The extent of pain was measured by visual analog score. Results： There were 8 cases in degree I, 28 cases in degree II, and 12 cases in degree III. The length of the cisternal segment of the affected side and the healthy side was （9.17±3.30） mm and （9.53±2.50） mm respectively, showing no statistical difference （P〉0.05）. The area of the cisternal segment of the affected side and the healthy side was （19.78±6.95） mm^2 and （26.37±13.20） mm^2 respectively, showing significant difference （P〈0.05）. The trigeminal-pontine angle of the affected side and the healthy side was 40.02°±14.43° and 52.57°±16.10° respectively, showing statistical difference （P〈0.05）. The cross-sectional area of cerebellopontine angle cistern of the affected side and the healthy side was （191.75±68.75） mm^2 and （236.74±64.79） mm^2 respectively, showing statistical difference （P〈0.05）. Positive correlation could be found between the degrees of NVC and the extent of pain in the patients with TN （P=0.033, r=0.309）. Conclusion： The morphologic changes can be diagnosed qualitatively and quantitatively with the high-resolution MR imaging. Sharp trigeminal-pontine angle, narrow area of the cerebellopontine angle cistern increase the chance of neurovascular contact, and cause TN easily. There is correlation between the degrees of NVC and the extent of pain in the patients with TN.