Lilja Ylva, Ljungberg Maria, Starck Göran, Malmgren Kristina, Rydenhag Bertil, Nilsson Daniel T
Institute of Neuroscience and Physiology, Department of Clinical Neuroscience and Rehabilitation, The Sahlgrenska Academy at the University of Gothenburg, Per Dubbsgatan 14, 413 46, Gothenburg, Sweden,
Acta Neurochir (Wien). 2015 Jun;157(6):947-56; discussion 956. doi: 10.1007/s00701-015-2403-y. Epub 2015 Apr 7.
Postoperative visual field defects are common after temporal lobe resection because of injury to the most anterior part of the optic radiation, Meyer's loop. Diffusion tensor tractography is a promising technique for visualizing the optic radiation preoperatively. The aim of this study was to assess the anatomical accuracy of Meyer's loop, visualized by the two most common tractography methods—deterministic (DTG) and probabilistic tractography (PTG)—in patients who had undergone temporal lobe resection.
Eight patients with temporal lobe resection for temporal lobe pathology were included. Perimetry and diffusion tensor imaging were performed pre- and postoperatively. Two independent operators analyzed the distance between the temporal pole and Meyer's loop (TP-ML) using DTG and PTG. Results were compared to each other, to data from previously published dissection studies and to postoperative perimetry results. For the latter, Spearman's rank correlation coefficient (r(s)) was used.
Median preoperative TP-ML distances for nonoperated sides were 42 and 35 mm, as determined by DTG and PTG, respectively. TP-ML assessed with PTG was a closer match to dissection studies. Intraclass correlation coefficients were 0.4 for DTG and 0.7 for PTG. Difference between preoperative TP-ML (by DTG and PTG, respectively) and resection length could predict the degree of postoperative visual field defects (DTG: r(s) = -0.86, p < 0.05; PTG: r(s) = -0.76, p < 0.05).
Both DTG and PTG could predict the degree of visual field defects. However, PTG was superior to DTG in terms of reproducibility and anatomical accuracy. PTG is thus a strong candidate for presurgical planning of temporal lobe resection that aims to minimize injury to Meyer's loop.
由于颞叶切除术会损伤视辐射最前端的迈耶袢，术后视野缺损很常见。扩散张量纤维束成像术是一种术前对视辐射进行可视化的有前景的技术。本研究的目的是评估在接受颞叶切除术的患者中，通过两种最常用的纤维束成像方法——确定性纤维束成像（DTG）和概率性纤维束成像（PTG）——可视化的迈耶袢的解剖学准确性。
纳入8例因颞叶病变行颞叶切除术的患者。术前和术后均进行视野检查和扩散张量成像。两名独立的操作人员使用DTG和PTG分析颞极与迈耶袢之间的距离（TP-ML）。将结果相互比较，与先前发表的解剖学研究数据以及术后视野检查结果进行比较。对于后者，使用斯皮尔曼等级相关系数（r(s)）。
非手术侧术前TP-ML距离的中位数，通过DTG和PTG分别测定为42和35毫米。用PTG评估的TP-ML与解剖学研究结果更相符。组内相关系数DTG为0.4，PTG为0.7。术前TP-ML（分别通过DTG和PTG）与切除长度之间的差异可预测术后视野缺损的程度（DTG：r(s)= -0.86，p<0.05；PTG：r(s)= -0.76，p<0.05）。
DTG和PTG均可预测视野缺损的程度。然而，在可重复性和解剖学准确性方面，PTG优于DTG。因此，PTG是旨在尽量减少对迈耶袢损伤的颞叶切除术术前规划的有力候选方法。
