Schulte-Altedorneburg Gernot, Linn Jennifer, Kunz Mathias, Brückmann Hartmut, Zausinger Stefan, Morhard Dominik
Institute for Diagnostic and Interventional Radiology, Neuroradiology and Nuclear Medicine, Klinikum München-Harlaching, Städtisches Klinikum München GmbH, Sanatoriumsplatz 2, D-81545, Munich, Germany.
Department of Neuroradiology, Klinikum Grosshadern, Ludwig-Maximilian-University, Munich, Germany.
Radiol Med. 2016 Mar;121(3):200-5. doi: 10.1007/s11547-015-0588-z. Epub 2015 Oct 17.
Endoscopic third ventriculostomy (ETV) is an effective treatment in patients with obstructive hydrocephalus caused by aqueductal stenosis. Operative failure may occur if an unnoticed membrane below the floor of the third ventricle is present, such as Liliequist's membrane (LM). To analyze how often LM can be visualized by high-resolution heavily T2-weighted 3D-MRI prior to ETV, and to find out potential reasons for diagnostic failure.
Preoperative 3D-MR images of 37 consecutive patients (19 female, median 42 years) were retrospectively analyzed. Visualization of three LM segments (sellar, diencephalic, mesencephalic), dimensions of the space below the third ventricle, and extent of hydrocephalus were measured. Image quality was scored (score 1[poor] to 3[excellent]). Preoperative imaging findings were compared with intraoperative findings.
Patients were subdivided into group 1 (no segment of LM identified, n = 18), and group 2 (at least one segment of LM was identified, n = 19). The sellar segment of LM was most often positively identified (10 out of 19 cases). The mean distance between the pons and the sella/clivus was significantly shorter in group 1 than in group 2 (3.7 vs. 6.2 mm; p < 0.01). Other variables, such as the distance between tip of the pons and the mamillary bodies as well as the image quality, were not significantly different between both groups. Intraoperatively, LM was present in 78 % of group 2 patients, and in 28 % of group 1 patients, respectively (p < 0.03).
LM can be detected in about half of patients prior to ETV. Reduced PSD influences visualization of LM.
内镜下第三脑室造瘘术（ETV）是治疗导水管狭窄所致梗阻性脑积水患者的一种有效方法。如果第三脑室底部下方存在未被注意到的膜，如Liliequist膜（LM），则可能发生手术失败。分析在ETV术前通过高分辨率重T2加权三维磁共振成像（3D-MRI）能够观察到LM的频率，并找出诊断失败的潜在原因。
回顾性分析37例连续患者（19例女性，中位年龄42岁）的术前3D-MR图像。测量三个LM节段（鞍区、间脑区、中脑区）的显示情况、第三脑室下方间隙的尺寸以及脑积水的程度。对图像质量进行评分（1分[差]至3分[优]）。将术前影像学检查结果与术中结果进行比较。
患者被分为1组（未识别出LM节段，n = 18）和2组（至少识别出一个LM节段，n = 19）。LM的鞍区节段最常被明确识别（19例中有10例）。1组脑桥与鞍底/斜坡之间的平均距离显著短于2组（3.7对6.2 mm；p < 0.01）。其他变量，如脑桥尖端与乳头体之间的距离以及图像质量，两组之间无显著差异。术中，2组患者中有78%存在LM，1组患者中有28%存在LM（p < 0.03）。
在ETV术前约一半的患者中可检测到LM。鞍底至脑桥距离减小影响LM的显示。
