CT及MR血管造影图像融合评估原发性三叉神经痛患者三叉神经入脑干区血管、神经及骨性结构的关系

CT and MR angiography image fusion for evaluating relationships of vascular,nerve and bony structures of trigeminal nerve root entry zone in patients with primary trigeminal neuralgia

目的观察CT及MR血管造影(MRA)双模态图像融合评估原发性三叉神经痛(PTN)患者三叉神经入脑干区(REZ)血管、神经及骨性结构的关系的价值。方法回顾性分析10例PTN患者头部CT及MRA,将数据三维可视化后,分别于CT与MRA图中选取9个解剖标记点进行配准,根据配准后标记点的欧氏距离选出5个融合标记点用于图像融合;计算融合标记点的配准误差(FRE),评估图像融合精度。基于MRA数据重建脑底动脉及神经模型,观察REZ处血管与三叉神经根的空间位置关系,判定PTN责任血管;测量并比较患侧与对侧责任血管与三叉神经根、三叉神经压迹及卵圆孔之间距离的差异。结果10例图像融合精度均良好,标记点FRE为1.862~3.156 mm,PTN责任血管均为小脑上动脉。患侧小脑上动脉与三叉神经压迹距离[(0.531±0.153)mm]及与卵圆孔的距离[(20.955±1.147)mm]均小于对侧[(2.573±1.050)mm、(24.864±1.807)mm,P均<0.001],与三叉神经根的距离[(5.024±1.063)mm]与对侧差异无统计学意义[(5.971±1.292)mm,P=0.081]。结论CT及MRA图像融合有助于定量观察PTN患者REZ血管与骨性结构及三叉神经根的毗邻关系。

Objective To explore the value of dual-mode image fusion based on CT and MR angiography(MRA)for evaluating relationships of vascular,nerve and bony structures of the trigeminal nerve root entry zone(REZ)in patient with primary trigeminal neuralgia(PTN).Methods Data of head CT and MRA of 10 PTN patients were retrospectively analyzed.After 3D visualization,9 anatomical markers were selected based on CT and MRA respectively for registration,among which 5 were taken as fusion markers for image fusion according to the Euclidean distance of the markers.The fiducial registration error(FRE)of fusion markers were calculated to evaluate the accuracy of image fusion.The artery and nervous models were reconstructed based on MRA,and the spatial relationship of vessels and trigeminal nerve roots of REZ were observed to judge the responsible vessel of PTN.The distance between responsible vessels and trigeminal nerve roots,trigeminal nerve traces and foramen ovale were measured and compared between the involved side and the opposite side.Results The accuracy of image fusion was good in all 10 patients,and FRE of fusion markers was 1.862-3.156 mm.The superior cerebellar artery was the responsible vessel of PTN in all 10 cases.The distance between superior cerebellar artery and trigeminal nerve impression([0.531±0.153]mm)and foramen ovale([20.955±1.147]mm)in the involved side were shorter than those in the opposite side([2.573±1.050]mm,[24.864±1.807]mm,both P<0.001),while no significant difference of the distances was found between superior cerebellar artery and trigeminal nerve root in the involved side([5.024±1.063]mm)and the opposite side([5.971±1.292]mm,P=0.081).Conclusion CT and MRA image fusion was helpful for quantitative analysis of relationships of blood vessels,bone structures and trigeminal nerve root in REZ of PTN patients.