James Jija S, Radhakrishnan Ashalatha, Thomas Bejoy, Madhusoodanan Mini, Kesavadas Chandrashekharan, Abraham Mathew, Menon Ramshekhar, Rathore Chaturbhuj, Vilanilam George
Department of Imaging and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695011, India.
R Madhavan Nayar Centre for Comprehensive Epilepsy Care, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695011, India.
Epilepsy Res. 2015 Feb;110:95-104. doi: 10.1016/j.eplepsyres.2014.11.020. Epub 2014 Nov 27.
Whether Meyer's loop (ML) tracking using diffusion tensor imaging tractography (DTIT) can be utilized to avoid post-operative visual field deficits (VFD) after anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE) using a large cohort of controls and patients. Also, we wanted to create a normative atlas of ML in normal population.
DTIT was used to study ML in 75 healthy subjects and 25 patients with and without VFD following ATL. 1.5T MRI echo-planar DTI sequences with DTI data were processed in Nordic ICE using a probabilistic method; a multiple region of interest technique was used for reconstruction of optic radiation trajectory. Visual fields were assessed in patients pre- and post-operatively.
Results of ANOVA showed that the left ML-TP distance was less than right across all groups (p = 0.01). The average distance of ML from left temporal pole was 37.44 ± 4.7 mm (range: 32.2-46.6 mm) and from right temporal pole 39.08 ± 4.9 mm (range: 34.3-49.7 mm). Average distance of left and right temporal pole to tip of temporal horn was 28.32 ± 2.03 mm (range: 26.4-32.8 mm) and was 28.92 ± 2.09 mm, respectively (range: 25.9-33.3 mm). If the anterior limit of the Meyer's loop was ≤38 mm on the right and ≤35 mm on the left from the temporal pole, they are at a greater risk of developing VFDs.
DTIT is a novel technique to delineate ML and plays an important role in planning surgical resection in TLE to predict post-operative visual performance and disability.
利用大量对照人群和患者，探讨采用扩散张量成像纤维束示踪法（DTIT）追踪迈耶袢（ML）是否可用于避免耐药性颞叶癫痫（TLE）患者行前颞叶切除术（ATL）后出现术后视野缺损（VFD）。此外，我们希望创建正常人群中ML的标准化图谱。
采用DTIT研究75名健康受试者以及25名ATL术后有或无VFD的患者的ML。在Nordic ICE中使用概率方法处理具有DTI数据的1.5T MRI回波平面DTI序列；采用多感兴趣区技术重建视辐射轨迹。对患者术前和术后的视野进行评估。
方差分析结果显示，所有组中左侧ML-颞叶极距离均小于右侧（p = 0.01）。ML距左侧颞极的平均距离为37.44±4.7毫米（范围：32.2 - 46.6毫米），距右侧颞极39.08±4.9毫米（范围：34.3 - 49.7毫米）。左右颞极至颞角尖的平均距离分别为28.32±2.03毫米（范围：26.4 - 32.8毫米）和28.92±2.09毫米（范围：25.9 - 33.3毫米）。如果迈耶袢的前界距颞极右侧≤38毫米且左侧≤35毫米，则患者发生VFD的风险更高。
DTIT是一种描绘ML的新技术，在TLE手术切除规划中对预测术后视觉功能和残疾情况起着重要作用。
