Sartoretti-Schefer S, Kollias S, Wichmann W, Valavanis A
Institute of Neuroradiology, University Hospital of Zürich, Switzerland.
AJNR Am J Neuroradiol. 1998 Mar;19(3):491-5.
Our objective was to identify histologically and intraoperatively verified focal nerve thickening of the distal intrameatal segment on three-dimensional fast spin-echo (FSE) T2-weighted MR images as a new diagnostic criterion in patients with inflammatory peripheral facial nerve palsy.
Twenty-two patients with clinically diagnosed unilateral (n = 20) or bilateral (n = 2) inflammatory peripheral facial nerve palsy were examined on a 1.5-T MR imager using noncontrast and contrast-enhanced T1-weighted SE sequences and 3-D T2-weighted FSE sequences with secondary reformations. Abnormal contrast enhancement and possible focal nerve thickening of the distal intrameatal segment, labyrinthine nerve segment, and geniculate ganglion region were analyzed prospectively.
In all patients, the T1-weighted postcontrast SE images showed characteristic smooth, linear, abnormally intense contrast enhancement of the distal intrameatal segment, indicating peripheral inflammatory nerve palsy. In 23 nerves (96%) a focal bulbous nerve thickening of the distal intrameatal segment was observed on 3-D T2-weighted FSE images. In 100% of patients with peripheral inflammatory facial nerve palsy, postcontrast T1-weighted SE images showed a smooth, linear, and abnormally intense contrast enhancement of the distal intrameatal segment; reformatted very thin 3-D T2-weighted FSE images showed a focal bulbous nerve thickening of the distal intrameatal segment in 96% of patients. These findings corresponded to intraoperative and histologic findings.
Three-dimensional T2-weighted FSE sequences are fast and cheap compared with T1-weighted postcontrast images, but secondary reformations are time-consuming and require exact anatomic knowledge for careful analysis of the different nerve segments.
我们的目标是在三维快速自旋回波（FSE）T2加权磁共振成像（MR）上，将组织学和术中证实的内耳道远端节段局灶性神经增粗作为炎性周围性面神经麻痹患者的一项新诊断标准。
对22例临床诊断为单侧（n = 20）或双侧（n = 2）炎性周围性面神经麻痹的患者，使用1.5-T MR成像仪，采用非增强和增强T1加权自旋回波序列以及具有二次重建的三维T2加权FSE序列进行检查。前瞻性分析内耳道远端节段、迷路神经节段和膝状神经节区域的异常对比增强及可能的局灶性神经增粗情况。
在所有患者中，T1加权增强后自旋回波图像显示内耳道远端节段有特征性的平滑、线性、异常强化，提示周围炎性神经麻痹。在三维T2加权FSE图像上，23条神经（96%）观察到内耳道远端节段局灶性球样神经增粗。在100%的周围炎性面神经麻痹患者中，增强后T1加权自旋回波图像显示内耳道远端节段平滑、线性且异常强化；重建的极薄层三维T2加权FSE图像显示96%的患者内耳道远端节段有局灶性球样神经增粗。这些发现与术中及组织学结果相符。
与T1加权增强后图像相比，三维T2加权FSE序列快速且成本低，但二次重建耗时，且需要精确的解剖学知识以仔细分析不同神经节段。
