蛛网膜下腔MR仿真内镜成像技术与临床意义

MR Virtual Endoscopy of Subarachnoid Space: Technique and Clinical Value

目的 探讨蛛网膜下腔磁共振仿真内镜 (MRVE)成像技术、方法及临床价值。资料与方法 对临床要求常规序列检查的患者采用二维快速自旋回波重T2 序列 (2DHT2 FSE)加行磁共振水成像 (MRH) ,其中颅脑 15例 ,脊椎 11例 ,源影像数据传输至工作站利用导航软件行仿真内镜 (VE)后处理重建成像。结果 在 2DHT2 FSE图像上 ,脑脊液呈高信号亮色 ,明显高于邻近组织结构信号 ,采用“黑底白影”阈值方式、2 5 0～ 110 0阈值重建获得了蛛网膜下腔VE图像。VE准确三维地展示了蛛网膜下腔及其邻近和穿行其间的脑、颅内腔、脊髓、椎管内腔、神经、血管与病变 ,对脑、脊髓表面结构 ,脑垂体、松果体和脑血管 ,部分颅神经起源、走行等显示颇佳 ,并可靠检出了小脑扁桃体下疝、听神经瘤、脊髓圆锥低位和椎管肿瘤、椎间盘突出等病变。结论 MRH是蛛网膜下腔VE有效的源影像技术 ,VE为评价蛛网膜下腔、脑、脊髓及其血管、神经正常解剖、变异与病变提供了一种安全、无创性。

Objective To discuss the technique and clinical value of MR virtual endoscopy (VE) of subarachnoid space.Materials and Methods MR hydrography (MRH) by using 2D heavily T 2 weighted fast spin echo pulse sequence (2D HT 2 FSE) was performed in 26 cases, including brain (n=15) and spine (n=11). Source imaging data sets were sent to the workstation (Advantage Windows 3.1) and the images were reconstructed by navigator software (Navigator Version 2.0.8).Results On 2D HT 2 FSE images, subarachnoid space presented as bright high signal, while the other tissue as dark signal. Virtual endoscopic images of subarachnoid space were created by using 'white in black' threshold value (250～1100). VE well displayed the 3D anatomy of subarachnoid space, some cranial nerves and vessels, pituitary gland and pineal gland. Cranial and spinal diseases, including tonsillar herniation, acoustic neuroma, lower positioned medullary cone, intervertebral disc protrusion and spinal cord tumors, were clearly demonstrated. Conclusion MRH is an effective source imaging technique for VE of subarachnoid space. VE is a new noninvasive technique for evaluating the anatomy of subarachnoid spaces, brain, spinal cord and related lesions