内侧颞叶癫痫患者颞叶及颞叶外低灌注的动脉自旋标记MRI

Temporal and extra-temporal hypoperfusion in medial temporal lobe epilepsy evaluated by arterial- spin-labeling based MRI

目的评价基于动脉自旋标记（ASL）的MRI技术在内侧颞叶癫痫（mTLE）定侧方面的应用价值，探讨mTLE癫痫网络脑区的脑灌注改变及其临床相关情况。方法选取25例左侧mTLE、23例右侧mTLE患者及30名正常志愿者，通过脉冲式ASL序列技术进行MR扫描，并采集脑血流量（CBF）数据。采用基于体素的方差分析技术，寻找mTLE患者相比正常对照组脑CBF改变的脑区，并分析其与临床病程的相关性。采用基于感兴趣区分析的技术，计算mTLE患者双侧颞叶灌注的偏侧化指数，初步评价其在颞叶癫痫定侧方面的应用价值。结果与正常对照组相比，mTLE患者表现为双侧颞叶内侧和外侧区域、双侧额顶叶，以及与脑默认模式网络有关的脑区CBF降低，且以患侧为著；患侧颞叶的CBF值与癫痫病程呈负相关（r=-0．51，P〈0．01）。通过对两组患者CBF值偏侧化指数计算，发现当偏侧化指数值为-0．01时，依据CBF进行mTLE定侧的敏感度为76．0％（19／25）、特异度为78．3％（18／23）。结论基于ASL的MR成像技术揭示mTLE颞叶及颞叶外脑灌注的降低，反映了内侧颞叶癫痫网络功能受损的性质；此技术具有较好的癫痫临床定侧价值。

Objective To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy （mTLE） by using arterial-spin-labeling （ASL） based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status. Methods Twenty-five patients with left-sided and 23 with right-sided mTLE were enrolled, and 30 healthy volunteers were recruited. The cerebral blood flow （ CBF ） of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner . The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis. The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the nol^nal side in matched region in mTLE group. Results Compared with the volunteers, the patients with mTLE showed the decrease of CBF in the bilateral medial and lateral temporal, the frontal and parietal regions relating to the default-mode network and more serious in lesion side. The CBF values of the medial temporal lobe were negatively correlated with the epilepsy duration （r = -0. 51 ,P 〈 0. 01 ）. The asymmetric index of C BF as -0. 01 has a 76. 0% （ 19/25 ） sensitivity and a 78.3% （ 18/23 ） specificity to distinguish the lesion side. Conclusions The decrease of CBF in the temporal and extra-temporal region by ASL-based MRI suggests the functional abnormalities in the network involved by mTLE. The ASL technique is a useful tool for lateralizing the unilateral mTLE.