Departments of Neuroradiology, Klinikum Grosshadern, Ludwig-Maximilians University, Marchioninistrasse 5, 81377 Munich, Germany.
Radiology. 2011 Feb;258(2):524-30. doi: 10.1148/radiol.10100477. Epub 2010 Nov 9.
To preoperatively detect, by using diffusion-tensor imaging coregistered with anatomic magnetic resonance (MR) imaging, suspected microstructural tissue changes of the trigeminal nerves in patients with trigeminal neuralgia (TN) resulting from neurovascular compression.
The study was approved by the institutional review board, and written informed consent was obtained from all patients. Twenty patients (mean age, 51.3 years) with TN and evidence of neurovascular contact were examined with use of a 3.0-T MR unit combined with an eight-channel head coil before undergoing surgical decompression. A single-shot diffusion-tensor echo-planar sequence was used along 15 different diffusion directions, with a b value of 1000 sec/mm(2) and a section thickness of 2 mm. For anatomic correlation, 0.6-mm isotropic three-dimensional fast imaging employing steady-state images were acquired for coregistration with the functional diffusion-tensor maps. After region of interest placement, mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for each nerve by using the paired-sample two-tailed t test (with P < .005 indicating significance) and compared with surgical findings.
FA was significantly lower (P = .004) on the trigeminal neuralgia-affected side (mean FA, 0.203) than on the contralateral side (mean FA, 0.239). ADCs were nearly identical between the normal and TN-affected nerve tissues.
These findings suggest that diffusion-tensor imaging enables the identification and quantification of anisotropic changes between normal nerve tissue and TN-affected trigeminal nerves. Coregistration of anatomic three-dimensional fast imaging employing steady-state imaging and diffusion-tensor imaging facilitates excellent delineation of the cisternal segments of the trigeminal nerves.
通过扩散张量成像与解剖磁共振（MR）成像配准，术前检测因神经血管压迫导致三叉神经痛（TN）的三叉神经疑似微观结构组织变化。
该研究经机构审查委员会批准，并获得所有患者的书面知情同意。使用配备 8 通道头部线圈的 3.0T MR 设备对 20 例经证实存在神经血管接触的 TN 患者进行检查，这些患者均即将接受手术减压。采用单次激发扩散张量回波平面序列，在 15 个不同扩散方向施加 b 值为 1000 sec/mm²的扩散张量，层厚为 2mm。为了进行解剖学相关性分析，采集 0.6mm 各向同性三维稳态成像进行同功能扩散张量图配准。放置感兴趣区后，使用配对样本双侧 t 检验（P<0.005 表示有统计学意义）计算每根神经的平均各向异性分数（FA）和表观扩散系数（ADC）值，并与手术结果进行比较。
患侧（FA 均值为 0.203）的 FA 值显著低于对侧（FA 均值为 0.239）（P=0.004）。正常和 TN 受累神经组织的 ADC 值几乎相同。
这些发现表明扩散张量成像能够识别和量化正常神经组织和 TN 受累三叉神经之间的各向异性变化。采用稳态成像的解剖学三维快速成像与扩散张量成像的配准有助于极好地描绘三叉神经池段。
