Epilepsy develops in 50 in every 100 000 people per year; in a third of these people, antiepileptic drugs do not control seizures.1 About half of these latter individuals have focal epilepsy that is potentially amenable to neurosurgical treatment if there is evidence to suggest a single focal network underlying the epilepsy, if the individual would be able to withstand neurosurgery,2 and if they do not have severe comorbidities, such as active cancer, advanced vascular disease, or dementia.
每10万人中就有50人发生癫痫，其中三分之一的人服用抗癫痫药物不能控制癫痫发作。1如果有证据表明癫痫发作的基础是单一的局灶性网络，如果患者能够承受神经外科手术，如果他们没有严重的合并症，如活动性癌症、晚期血管疾病或痴呆，那么这些患者中大约有一半患有局灶性癫痫，有可能接受神经外科手术治疗。
Brain imaging is of fundamental importance to diagnosis and treatment of epilepsy, particularly when neurosurgical treatment is being considered. Dramatic advances have been made in brain imaging applied to epilepsy in the past 20 years, principally because of advances in MRI scanner technology, acquisition protocols, and image processing methods, and in nuclear medicine.3 In this Review, we focus principally on advances made since 2005 that are of potential clinical importance to the practising neurologist. We first review developments in structural brain imaging with MRI and post-acquisition processing methods to identify cerebral abnormalities that might cause epilepsy, the identification of which might lead to consideration of surgery. We then describe the mapping of areas of cortex that are essential for language, motor, and memory functions (eloquent cortex) and the crucial white matter pathways in the brain. Next, we review PET and other imaging methods to infer the localisation of cerebral networks that could generate epileptic seizures in the context of MRI findings that are inconclusive or discordant with clinical and EEG data. Finally, we review the integration of multimodal three-dimensional imaging data and how these methods have an evolving role in the design of treatment strategies for individual patients, and consider forthcoming advances. Panel 1 comprises a glossary of MRI terms used in this Review.
脑成像对癫痫的诊断和治疗至关重要，特别是在考虑神经外科治疗时。在过去的20年中，脑成像在应用于癫痫方面取得了巨大的进展，主要是由于 MRI 扫描仪技术，采集协议和图像处理方法以及核医学的进步。3在这篇综述中，我们主要关注自2005年以来取得的进展，这些进展对于执业神经科医生具有潜在的临床重要性。我们首先回顾了 MRI 和采集后处理方法在结构性脑成像方面的进展，以确定可能引起癫痫的脑异常，鉴定这些异常可能导致考虑手术。然后，我们描述了对语言、运动和记忆功能(雄辩皮层)至关重要的大脑皮层区域的映射，以及大脑中至关重要的白质通路。接下来，我们回顾 PET 和其他成像方法，以推断脑网络的定位，可能会产生癫痫发作的背景下的 MRI 结果是不确定的或不一致的临床和脑电图数据。最后，我们回顾了多模式三维成像数据的整合，以及这些方法在个体患者治疗策略设计中如何发挥作用，并考虑即将取得的进展。面板1包括本评论中使用的核磁共振术语的词汇表。
Glossary of MRI terms
核磁共振术语词汇
动脉自旋标记
An MRI technique that is used to produce quantitative maps of tissue perfusion without the need for intravenous contrast by magnetically labelling inflowing blood.
一种磁共振成像技术，用于生成组织灌注的定量图，无需通过磁性标记流入的血液进行静脉对比。
Curvilinear reformatting
曲线重新格式化
An alternative approach to traditional cross-sectional display (ie, sagittal, axial, and coronal) in which the brain is displayed at different depths from the surface, like the layers of an onion; this method enhances the localisation and detection of dysplastic lesions.
传统横断面显示(即矢状面，轴向和冠状面)的替代方法，其中大脑显示在表面的不同深度，如洋葱层; 这种方法增强了发育不良病变的定位和检测。
Diffusion imaging
扩散成像
An MRI technique in which the signal is modulated by the random diffusion of water molecules; the signal loss in areas of increased diffusion was first used clinically to detect early ischaemic stroke.
一种 MRI 技术，其中信号由水分子的随机扩散来调节; 扩散增加区域的信号丢失首先在临床上用于检测早期缺血性中风。
弥散张量成像
A development of diffusion-weighted imaging in which diffusion is measured in several directions in each voxel so that the predominant direction of diffusion can be established and used for tractography; further calculations can be used to derive quantitative tissue properties.
扩散加权成像技术的一种发展，其中在每个体素中以多个方向测量扩散，以便确定扩散的主要方向并用于纤维束成像; 进一步的计算可用于推导定量组织特性。
Diffusional kurtosis imaging
弥散峰度成像
An extension of diffusion-tensor imaging methods that is used to measure both Gaussian and non-Gaussian distribution of diffusion to provide greater detail about complex tissue microstructure.
扩散张量成像方法的扩展，用于测量高斯和非高斯扩散分布，以提供更多有关复杂组织微结构的细节。
Double-inversion recovery
双反转恢复
An MRI sequence with two additional pulses to suppress the signal from both white matter and CSF, which increases grey–white matter contrast and therefore facilitates the identification of grey matter lesions.
核磁共振序列加上两个额外的脉冲来抑制来自白质和脑脊液的信号，这增加了灰白质的对比度，因此有助于识别灰质病变。
Fluid-attenuated inversion recovery (FLAIR) imaging
流体衰减反转恢复(FLAIR)成像
A T2-weighted sequence with an additional pulse to suppress the signal from CSF, which improves the identification of periventricular lesions.
T2加权序列加上额外的脉冲抑制来自脑脊液的信号，这改善了脑室周围病变的识别。
Intracarotid amobarbital test (Wada test)
颈动脉内安巴比妥试验(和田试验)
A procedure in which one hemisphere is temporarily anaesthetised by intracarotid injection of sodium amobarbital to measure the laterality of language and memory functions.
用颈动脉内注射安巴比妥钠暂时麻醉一个半球以测量语言和记忆功能的偏侧性。
Neurite orientation dispersion and density imaging (NODDI)
神经元定向弥散和密度成像(NODDI)
An advanced model-based diffusion-weighted imaging method that is used to measure tissue properties such as intracellular volume fraction and the amount of dispersion of neurites (ie, axons and dendrites).
一种先进的基于模型的扩散加权成像方法，用于测量组织特性，如细胞内体积分数和神经突(即轴突和树突)的分散量。
Partial volume effects
部分体积效应
An artifact that leads to an error in characterisation of tissue type owing to the effects of averaging signal within a voxel as a result of limited resolution of the imaging system.
一种伪影，由于成像系统分辨率有限，导致体素内平均信号的影响，从而导致组织类型的角色塑造错误。
Phased-array coil
相控阵线圈
A type of MRI coil that receives signal to produce an image from several coils rather than a single coil to improve signal-to-noise ratio and facilitate faster imaging.
一种磁共振成像线圈，接收多个线圈产生的图像信号，而不是单个线圈产生的图像，以改善信噪比，便于更快地成像。
Region-of-interest-based approach
基于感兴趣区域的方法
A type of analysis applied to MRI data in which a specific region (eg, the hippocampus) is delineated manually or automatically to measure a property of that region.
一种应用于 MRI 数据的分析类型，其中特定区域(例如海马)被手动或自动描绘以测量该区域的特性。
Surface-based morphometry
基于表面的形态测量学
An approach to the study of brain shape and size (morphometry) that is used to investigate features of the brain surface such as cortical thickness and curvature.
一种研究大脑形状和大小的方法(形态测量学) ，用于研究大脑表面的特征，如皮层厚度和曲率。
Susceptibility-weighted imaging
磁化率加权成像
A newer MRI technique than T2*-gradient echo imaging that is sensitive to the effects of paramagnetic and diamagnetic compounds such as blood products and calcium; this method improves the identification of lesions such as cavernomas.
一种比 T2 * 梯度回波成像更新的 MRI 技术，它对顺磁性和反磁性化合物(如血液制品和钙)的影响敏感; 这种方法改善了对病变(如海绵状肿瘤)的识别。
T1-weighted imaging
T1加权成像
One of the basic MRI sequences that produces images in which contrast predominantly depends on the T1 relaxation times of the tissues; this weighting is typically used to emphasise anatomical structure.
其中一个基本的 MRI 序列产生的图像，其中对比度主要取决于组织的 T1弛豫时间; 这种加权通常用于强调解剖结构。
T2 relaxometry
T2弛豫测定法
A quantitative MRI technique used to measure T2 relaxation, in contrast to methods that produce images qualitatively affected by T2 relaxation (T2-weighted imaging); the resulting maps are helpful for the identification of hippocampal sclerosis.
一种用于测量 T2弛豫的定量 MRI 技术，与产生定性影响 T2弛豫的图像(T2加权成像)的方法相反; 得到的地图有助于识别海马硬化症。
T2-weighted imaging
T2加权成像
One of the basic MRI sequences that produces images in which contrast predominantly depends on the T2 relaxation times of the tissues; this weighting is typically used to emphasise pathological abnormalities.
其中一个基本的 MRI 序列产生的图像，其中对比度主要取决于组织的 T2弛豫时间; 这种加权通常用于强调病理异常。
T2*-gradient echo imaging
T2 * 梯度回波成像
A commonly used clinical MRI sequence that produces images sensitive to iron-containing compounds such as blood products; this method is helpful for the identification of vascular malformations and microbleeds.
一种常用的临床 MRI 序列，能产生对含铁化合物(如血液制品)敏感的图像; 这种方法有助于识别血管畸形和微出血。
Tractography
牵引仪
A non-invasive method to delineate white matter connections from diffusion-weighted imaging data; one approach is to trace the predominant direction of diffusion from diffusion-tensor imaging data.
一种从弥散加权成像数据描绘白质连接的非侵入性方法; 一种方法是从弥散张量成像数据追踪扩散的主要方向。
音量
The technique of measuring the volume of a structure, either manually or automatically; this method is useful for measuring hippocampal volumes to detect hippocampal atrophy.
手工或自动测量结构体积的技术; 这种方法可用于测量海马体积以检测海马萎缩。
Voxel-based morphometry
基于体素的形态测量学
A statistical approach to the study of brain shape and size (morphometry) that enables comparisons of brain imaging data from groups of people or from an individual with reference to template images, to identify where focal changes occur in properties such as grey matter volume.
研究大脑形状和大小(形态测量学)的统计学方法，能够比较来自一组人或来自个人的脑成像数据与模板图像，以确定在诸如灰质体积的属性中发生焦点变化的位置。
In the interpretation of imaging studies, an important factor is recognition of the difference between group studies, as used in neuroscience investigations to infer the functional anatomy of the brain and its abnormalities in a disorder, and clinical studies, in which the results affect the diagnostic and treatment pathways of individual patients. The latter are focused on individuals with medically refractory focal epilepsies, and their surgical treatment, in whom the finding of focal abnormalities might lead to a surgical solution and identification of critical structures might constrain the surgical approach.
在影像学研究的解释中，一个重要的因素是认识到组研究之间的差异，如在神经科学研究中用于推断大脑的功能解剖学及其在疾病中的异常，以及临床研究，其中结果影响个体患者的诊断和治疗途径。后者集中在具有医学难治性局灶性癫痫的个体及其手术治疗，其中局灶性异常的发现可能导致手术解决方案和关键结构的识别可能限制手术方法。
The prerequisite for imaging investigations in the presurgical assessment of patients with epilepsy is high-quality structural MRI, interpreted in the context of clinical and EEG data, with quantification of hippocampal volumes and T2 signal, to identify an epileptogenic lesion. If there is a relevant structural lesion that is concordant with the results of scalp video EEG telemetry and not close to eloquent cortex, the patient can be recommended for surgery, with functional MRI (fMRI) at this time to assess language lateralisation. If a resection is planned that is close to the optic radiation or corticospinal tract, diffusion imaging and tractography to help to optimise the surgical approach and minimise the risks of surgery is recommended. Figure 1 shows the place of imaging studies in the presurgical pathway.4
在癫痫患者的术前评估中进行成像研究的先决条件是高质量的结构 MRI，在临床和 EEG 数据的背景下进行解释，并定量海马体积和 T2信号，以鉴定致癫痫病变。如果存在与头皮视频脑电遥测结果一致的相关结构损伤，并且不接近雄辩的皮层，则可以推荐患者进行手术，此时使用功能性 MRI (fMRI)评估语言偏侧化。如果切除计划接近视觉放射或锥体束，扩散成像和纤维束成像可以帮助优化手术方式，最大限度地减少手术风险。图1显示了影像学研究在术前途径中的位置
Figure 1. The pathways of assessment for epilepsy surgery, showing the place of brain imaging
图1。癫痫手术的评估路径，显示脑成像的位置
18F-FDG=18F-fluorodeoxyglucose. EEG=electroencephalography. MEG=magnetoencephalography. Adapted from Duncan,4 by permission of Elsevier.
18F-FDG = 18F-氟脱氧葡萄糖，脑电图 = 脑电图，脑电图 = 脑磁图，改编自邓肯，经爱思唯尔许可。
If an individual has no relevant lesion on MRI, further acquisitions using the latest MRI hardware and techniques and post-acquisition processing methods might reveal a subtle abnormality, but findings should be interpreted with caution owing to the possibility of false-positive results. 18F-fluorodeoxyglucose (18F-FDG) PET is a useful next step because it can be used to identify a single area of hypometabolism that might lead directly to resection—eg, if there is reduced uptake in the anterior temporal lobe in the non-language dominant hemisphere—or, more commonly, to inform an intracranial EEG recording. If abnormalities are not identified on 18F-FDG PET imaging, subsequent investigations are geared towards generation of a hypothesis regarding the location of the epileptogenic zone that can be tested with intracranial EEG. These investigations include ictal SPECT and visualisation of interictal, and rarely ictal, epileptic activity with electrical source imaging (ESI), magnetic source imaging (MSI), and simultaneous EEG and fMRI (EEG-fMRI). In practical terms, the hierarchy of these investigations will depend on their availability in individual centres. Three-dimensional multimodal imaging has an evolving role in the integration of structural and functional data for the planning of invasive EEG studies and resections.
如果一个人在 MRI 上没有相关的病变，那么使用最新的 MRI 硬件和技术以及采集后处理方法的进一步采集可能会显示微妙的异常，但是由于可能出现假阳性结果，应该谨慎解释结果。18F-氟脱氧葡萄糖(18F-FDG) PET 是一个有用的下一步，因为它可以用来确定可能直接导致切除的单个代谢低下区域，例如，如果在非语言优势半球的前颞叶摄取减少，或者更常见的是，通知颅内脑电图记录。如果在18F-FDG PET 成像中没有发现异常，随后的研究旨在产生一个关于致痫区位置的假设，可以用颅内脑电图进行检测。这些研究包括发作性 SPECT 和发作间期(很少发作)癫痫活动的电源成像(ESI) ，磁源成像(MSI)以及同时 EEG 和 fMRI (EEG-fMRI)的可视化。实际上，这些调查的等级将取决于它们在各个中心的可用性。三维多模式成像在整合结构和功能数据以规划侵入性脑电图研究和切除方面具有不断发展的作用。
Structural MRI is the main neuroimaging technique for identification of an epileptogenic lesion. Localising and delineating the extent of the underlying lesion and its relation to eloquent cortex forms a crucial part of the assessment for surgery. Identification of a lesion leads to a greater chance of seizure freedom after surgery.5, 6 However, 15–30% of patients with refractory focal epilepsy do not have distinct lesions on MRI (ie, they are MRI negative).7, 8 The underlying pathological abnormalities, the acquisition protocol, and the interpretation, by human or computational analysis, are key determinants in the identification of structural abnormalities.
结构性磁共振成像是主要的神经影像学技术，以鉴别致痫性病变。定位和描绘潜在病变的范围及其与雄辩的皮层的关系形成了手术评估的关键部分。病变的识别导致手术后癫痫发作自由的机会更大[5,6]。然而，15-30% 的难治性局灶性癫痫患者在 MRI 上没有明显的病变(即 MRI 阴性)[7,8]。潜在的病理异常，采集方案和解释，通过人或计算分析，是识别结构异常的关键决定因素。
Acquiring images using an optimised epilepsy protocol maximises the potential to identify structural abnormalities. The basic protocol established by the International League Against Epilepsy9 includes whole-brain T1-weighted and T2-weighted imaging acquired with the minimum slice thickness possible in two orthogonal planes and a volumetric T1-weighted acquisition for three-dimensional reconstruction (figure 2). This guideline is 18 years old and updated guidance that takes into consideration recent advances made in brain imaging would now be appropriate.
采集图像使用优化的癫痫协议最大限度地发挥潜力，以确定结构异常。国际抗癫痫联盟9建立的基本方案包括全脑 T1加权和 T2加权成像，采用两个正交平面中可能的最小切片厚度和用于三维重建的体积 T1加权采集(图2)。这个指南已经有18年的历史了，考虑到最近在脑成像方面取得的进展的最新指南现在是合适的。
Figure 2. MRI acquisition protocols for the identification of structural cerebral abnormalities in epilepsy
图2。 MRI 采集方案用于鉴别癫痫的脑结构异常
Focal cortical dysplasia with cortical thickening and a blurred grey–white matter junction (circled) on (A) T1-weighted imaging and (B) with high signal intensity on T2-weighted FLAIR imaging. Right hippocampal sclerosis with volume loss (circled) on (C) T1-weighted imaging, (D) with high signal intensity on T2-weighted FLAIR imaging, and (E) with loss of internal architecture on T2-weighted PROPELLER imaging. (F) A cavernoma in the left inferior temporal gyrus (circled) can be seen clearly as an area of signal dropout on T2*-weighted images. (G) Application of a voxel-based image post-processing method to T1-weighted three-dimensional MRI data from a 38-year-old woman enabled enhanced visualisation of focal cortical dysplasia on the resulting junction image (blurred grey–white matter junction) and extension image (grey matter extending abnormally into white matter). The corresponding slice is shown on the original T1-weighted image. (A–F) were acquired on a 3 T scanner with (A, C) a three-dimensional fast spoiled gradient echo T1-weighted sequence (0.9375 × 0.9375 mm in-plane resolution, 1·1 mm slice thickness), (B) an axial and (D) an oblique coronal T2-weighted FLAIR sequence (0·9375 × 0·9375 mm in-plane resolution, 5 mm slice thickness), (E) a coronal oblique T2-weighted PROPELLER sequence (0·43 × 0·43mm in-plane resolution, 2 mm slice thickness), and (F) a coronal fast gradient recalled echo T2*-weighted sequence (0·9375 × 0·9375 mm in-plane resolution, 5 mm slice thickness). For all images, left side of image=right side of brain. FLAIR=fluid-attenuated inversion recovery. PROPELLER=periodically rotated overlapping parallel lines with enhanced reconstruction. Panel G adapted from Huppertz and colleagues,10 by permission of Elsevier.
在(A) T1加权成像和(B) T2加权 FLAIR 成像上具有高信号强度的局灶性皮质发育不良伴有皮质增厚和模糊的灰白质连接(圈)。(C) T1加权成像上体积丧失(圈起)的右海马硬化症，(D) T2加权 FLAIR 成像上具有高信号强度，以及(E)在 T2加权 PROPELLER 成像上具有内部结构丧失。(F)在 T2 * 加权像上可以清楚地看到左颞下回(圈起来)的海绵状细胞瘤是一个信号丢失的区域。(G)将基于体素的图像后处理方法应用于来自38岁女性的 T1加权三维 MRI 数据，使得得到的交界图像(模糊的灰白质连接)和延伸图像(灰质异常延伸到白质)上的局灶性皮质发育不良的可视化增强。对应的切片显示在原始的 T1加权图像上。(A，C)三维快速损坏梯度回波 T1加权序列(0.9375 × 0.9375 mm 平面内分辨率，1.1 mm 切片厚度) ，(B)轴向和(D)斜冠状 T2加权 FLAIR 序列(0.9375 × 0.9375 mm 平面内分辨率，5mm 切片厚度),(E)冠状斜 T2加权 PROPELLER 序列(0.43 × 0.43 mm 平面内分辨率，2mm 切片厚度)和(F)冠状快梯度回忆回波 T2 * 加权序列(0.9375 × 0.9375 mm 平面内分辨率，5mm 切片厚度)。对于所有的图像，图像的左侧 = 大脑的右侧。流体衰减反转恢复。PROPELLER = 周期性旋转的重叠平行线，具有增强的重建。G 组改编自 Huppertz 及其同事，10经爱思唯尔许可。
Additional sequences, in particular fluid-attenuated inversion recovery (FLAIR) MRI, have become available, and scanner hardware has improved (figure 2).10 Analysis of MRI data showing epileptogenic lesions in 2740 surgical patients in Bonn, Germany, led to a proposal for a specific MRI protocol (panel 2)11 that is advantageous from both a sensitivity and economic point of view and is now widely accepted.12
其他序列，特别是液体衰减反转恢复(FLAIR) MRI 已经可用，并且扫描仪硬件已经得到改善(图2)。10在德国波恩的2740名手术患者中显示致癫痫病变的 MRI 数据的分析导致提出了一个特定的 MRI 方案(图2)11，这是从敏感性和经济角度来看都是有利的，现在被广泛接受
MRI acquisition protocol for the identification of structural abnormalities in patients with epilepsy
MRI 采集方案在癫痫患者结构异常识别中的应用
Three-dimensional volumetric T1-weighted imaging (1 mm isotropic voxels)
三维体积 T1加权成像(1mm 各向同性体素)
This method provides excellent grey–white matter contrast and allows the assessment of cortical thickness and detection of malformations of cortical development. Images can be reformatted into any plane and post-processing techniques can be used to improve detection of abnormalities.
这种方法提供了良好的灰白质对比度，并允许评估皮层厚度和检测皮层发育的畸形。图像可以重新格式化成任何平面和后处理技术可以用来改善检测异常。
T2-weighted imaging (axial and coronal)
T2加权成像(轴位和冠状位)
This imaging method allows assessment of hippocampal architecture and cystic tissue components of other lesions. The two orthogonal planes allow small lesions to be distinguished from partial volume effects, which are minimised by acquiring images orthogonal to the long axis of the hippocampus.
这种成像方法可以评估其他病变的海马结构和囊性组织成分。两个正交平面可以区分小病灶和部分体积效应，通过获取与海马长轴正交的图像来最小化部分体积效应。
Fluid-attenuated inversion recovery imaging (axial and coronal)
流体衰减反转恢复成像(轴向和冠状)
This imaging method is sensitive to hippocampal sclerosis, focal cortical dysplasia, tumours, inflammation, and scars.
这种成像方法对海马硬化，局灶性皮质发育不良，肿瘤，炎症和疤痕敏感。
T2* gradient echo or susceptibility-weighted imaging (axial)
T2 * 梯度回波或磁化率加权成像(轴位)
This method is sensitive to calcified and vascular lesions, such as cavernomas and arteriovenous malformations.11
这种方法对钙化和血管病变敏感，如海绵状血管瘤和动静脉畸形
Imaging hardware has improved, with increased field strength and better coils and gradients. An increased field strength improves signal-to-noise ratio and enables greater spatial resolution. Rescanning surgical candidates who were MRI negative on a 1·5 T scanner using a 3 T scanner with phased-array coil MRI enabled identification of a lesion in 15 of 23 patients.13 A retrospective review of 804 unselected patients who had MRI at 1·5 T and subsequently at 3 T showed relevant new diagnoses in 37 (5%), in particular hippocampal sclerosis, focal cortical dysplasia, and dysembryoplastic neuroepithelial tumour.14 7 T imaging is anticipated to reveal further anatomical detail, including delineation of hippocampal subfields15, 16 and increased identification of abnormalities that are not evident on conventional clinical MRI. However, higher field strength brings with it challenges, including image distortion and artifacts, and issues with patient tolerance that can make clinical interpretation and decisions on the relevance of findings difficult.
成像硬件已经得到改善，增加了磁场强度和更好的线圈和梯度。增强的场强可以提高信噪比和空间分辨率。使用3T 扫描仪和相控阵线圈 MRI 对1.5 T 扫描仪上 MRI 阴性的手术候选者进行重新扫描，使23例患者中的15例能够识别病变。对804例未经选择的1.5 T MRI 和随后在3T 的患者进行回顾性分析显示相关的新诊断37例(5%) ，特别是海马硬化症，局灶性皮质发育不良和胚胎发育不良神经上皮肿瘤[14]。7T 成像预计将揭示进一步的解剖学细节，包括描绘海马亚区15,16和增加识别在常规临床 MRI 上不明显的异常。然而，更高的场强带来了它的挑战，包括畸变和伪影，以及患者耐受性的问题，这些问题可能会使临床解释和决定研究结果的相关性变得困难。
Even with optimum acquisition, scan interpretation is subject to the expertise of the radiologist. In patients undergoing surgery, sensitivity in detection of focal epileptogenic lesions was 39% from non-optimised imaging reported by non-experts, 50% when reported by experts, and 91% when an optimised acquisition was used and reported by experts.17 Curvilinear reformatting of volumetric T1-weighted images improves the display of gyral structure and helps to identify subtle abnormalities not seen on planar slices.18 The clear message is that both acquisition using an epilepsy protocol and reporting by a skilled neuroradiologist who has all the relevant clinical data increase greatly the identification of relevant lesions that might underlie epilepsy.
即使获得了最佳的获取，扫描解释仍然取决于放射科医生的专业知识。在接受手术的患者中，非专家报告的局灶性癫痫发作性病变的检测敏感性为39% ，专家报告的敏感性为50% ，专家报告的敏感性为91% 。体积 T1加权图像的曲线重新格式化改善了回旋结构的显示，并有助于识别平面切片上未见的微妙异常。18明确的信息是，使用癫痫方案进行采集和由熟练的神经放射学家报告，所有相关临床数据大大增加了可能导致癫痫的相关病变的识别。
A substantial development in the past decade has been the automated quantitative assessment of structural data, which can be applied to datasets from individuals.19 The most commonly missed diagnoses in MRI-negative patients are hippocampal sclerosis and focal cortical dysplasia.
过去十年的一个重大发展是结构数据的自动定量评估，可以应用于来自个体的数据集。 MRI 阴性患者最常错过的诊断是海马硬化症和局灶性皮质发育不良。
Hippocampal sclerosis is the most common cause of surgically remediable temporal lobe epilepsy and can be assessed with volumetry and T2 relaxometry. Quantification of hippocampal changes is particularly important, and strongly recommended, when considering epilepsy surgery, to detect subtle atrophy and signal changes that might not be identified visually and to establish whether the contralateral hippocampus is structurally normal. Bilateral hippocampal abnormalities raise concerns of a reduced chance of seizure freedom after anterior temporal lobe resection and an increased risk of memory impairment.20 Time-consuming manual volumetry can be replaced by automated segmentation, which is available freely on the internet,21 and localised shape changes can be detected even in patients who seem to be MRI negative.22 Voxel-based approaches to T2 relaxometry might be more sensitive than traditional approaches based on region of interest analyses.23
海马硬化是手术可治疗的脑颞叶癫痫症最常见的原因，可通过容量测定法和 t2松弛测定法进行评估。当考虑癫痫手术时，海马变化的量化特别重要，并强烈建议检测可能无法视觉识别的细微萎缩和信号变化，并确定对侧海马是否结构正常。双侧海马异常引起了颞叶前切除术后癫痫发作自由度降低和记忆障碍风险增加的担忧.20耗时的手动体积测量可以被互联网上免费提供的自动分割所取代[21] ，即使在 MRI 阴性的患者中也可以检测到局部形状变化.22基于体素的 T2弛豫测量方法可能比基于感兴趣区域分析的传统方法更敏感.23
Computerised analysis of hippocampal FLAIR signal has been used to identify hippocampal sclerosis with 97% sensitivity and 95% specificity,24 and a combination of hippocampal volumetry and FLAIR signal measurements has been used to identify moderate and severe hippocampal sclerosis.25 However, findings from a direct comparison between automated FLAIR signal analysis and hippocampal T2 relaxometry suggested that T2 relaxometry was more sensitive.26
海马 FLAIR 信号的计算机化分析已被用于鉴定海马硬化症，敏感性为97% ，特异性为95% [24] ，海马容积测量和 FLAIR 信号测量的组合已被用于鉴定中度和重度海马硬化[25]。然而，直接比较自动 FLAIR 信号分析和海马 T2弛豫测量表明 T2弛豫测量更敏感
Apart from manual hippocampal volumetry, the use of these techniques has largely remained confined to the centres that developed them and a few collaborating centres. For wide dissemination, validated methods need to be readily available, be quick and intuitive to use, and have adequate technical support in place.
除了手动海马体积测量，这些技术的使用在很大程度上仍然局限于发展它们的中心和少数合作中心。对于广泛的传播，验证的方法需要随时可用，快速和直观的使用，并有足够的技术支持到位。
Cortical malformations, in particular focal cortical dysplasia, underlie many paediatric and around a quarter of adult MRI-negative refractory epilepsies.27 Imaging findings include focal cortical thickening, blurring of the grey–white matter junction, and high signal on T2-weighted or FLAIR images in underlying white matter.28 However, MRI is often normal, particularly in type I focal cortical dysplasia, and up to 80% of focal cortical dysplasia lesions cannot be visually detected when located in the depths of a sulcus.29 Advances in imaging acquisition protocols are likely to enable the detection of previously unidentified abnormalities such as focal cortical dysplasia. For example, double-inversion recovery suppresses signal from both CSF and white matter, improving contrast in the cortex.30 Arterial spin labelling can be used to visualise tissue perfusion, and reduced blood flow might co-localise with focal cortical dysplasia.31 Development in diffusion imaging methods such as neurite orientation dispersion and density imaging or diffusional kurtosis imaging, which provide more detail on tissue microstructure, increase sensitivity for the detection of focal cortical dysplasia (figure 3).32
皮质畸形，特别是局灶性皮质发育不良，是许多儿童和约四分之一的成人 MRI 阴性难治性癫痫的基础[27]。影像学检查结果包括局灶性皮质增厚，灰白质交界处模糊，以及 T2加权或 FLAIR 图像上的高信号。然而，MRI 通常是正常的，特别是在 I 型局灶性皮质发育不良中，高达80% 的局灶性皮质发育不良病变位于沟深处时无法视觉检测[29]。成像采集方案的进展可能使得能够检测到先前未知的异常，如局灶性皮质发育不良。例如，双反转恢复抑制来自 CSF 和白质的信号，改善皮层的对比度.30动脉自旋标记可用于可视化组织灌注，减少的血流量可能与局灶性皮质发育不良共定位.31扩散成像方法的发展，如神经突方向分散和密度成像或扩散峰度成像，其提供更多关于组织微观结构的细节，增加检测局灶性皮质发育不良的灵敏度(图3)
Figure 3. Neurite orientation dispersion and density imaging for the detection of focal cortical dysplasia
图3。神经突定向弥散和密度成像检测局灶性皮质发育不良
A 27-year-old male with focal cortical dysplasia in the left inferior temporal gyrus. The area (circled) is defined poorly on structural images including volumetric T1-weighted (A) and T2-weighted coronal oblique (B) images and on standard diffusion images including fractional anisotropy (C) and mean diffusivity (D) maps. Focal cortical dysplasia is easily visible as a reduced intracellular volume fraction on neurite orientation dispersion and density imaging, an advanced diffusion MRI sequence (E). Reproduced from Winston and colleagues.32
一位27岁男性，左侧颞下回局灶性皮质发育不良。在包括体积 T1加权(A)和 T2加权冠状斜(B)图像的结构图像和包括分数各向异性(C)和平均扩散率(D)图的标准扩散图像上，区域(圈起来)定义不佳。局灶性皮质发育不良在神经突定向弥散和密度成像(一种先进的磁共振扩散成像序列)上很容易看到减少的细胞内容积分数。转载自温斯顿及其同事。32
Voxel-based morphometry (VBM) was originally applied to T1-weighted images for the quantitative analysis of grey and white matter distribution,33 initially for group comparisons, but subsequently to compare an individual with a control population.19 Findings from an initial study showed that 21 of 27 patients with focal cortical dysplasia were correctly identified.34 Voxel-based analysis has been applied to T2 relaxometry maps35 and FLAIR images to increase sensitivity for detection of focal cortical dysplasia36 and for detection of abnormalities in those who are MRI negative.37 Improved detection of focal cortical dysplasia has been achieved with a morphometric analysis procedure based on VBM methods that produces a junction map to highlight blurring of the grey–white matter boundary and an extension map to delineate abnormally deep sulci (figure 2G).10 In one study, morphometric analysis complemented visual reading of MRI scans by an expert neuroradiologist.38 As with many other image analysis instruments, there has not been widespread uptake of these methods, which are often perceived by clinicians outside specialist units as being complicated and non-intuitive.
基于体素的形态测量(VBM)最初应用于 T1加权图像以定量分析灰质和白质分布[33] ，最初用于组比较，但随后用于比较个体与对照人群。初步研究结果显示，27例局灶性皮质发育不良患者中有21例被正确识别。34基于体素的分析已经应用于 T2弛豫测量图35和 FLAIR 图像，以增加检测局灶性皮质发育不良36和检测 MRI 阴性者异常的灵敏度。基于 VBM 方法的形态测量分析程序已经改善了局灶性皮质发育不良的检测，该程序产生连接图以突出灰白质边界的模糊和描绘异常深沟的延伸图(图2G)。在一项研究中，形态测量分析补充了专家神经放射学家对 MRI 扫描的视觉阅读。38与许多其他图像分析仪器一样，这些方法尚未得到广泛采用，专科单位以外的临床医生往往认为这些方法复杂且不直观。
Focal cortical dysplasia can be associated with abnormal gyral and sulcal patterns not detected with VBM. Surface-based morphometry techniques generate geometric models of the cortical surface that allow features such as cortical thickness to be measured. This technique can be extended to analyse many morphological (cortical thickness, curvature, and depth) and textural (blurring of grey–white matter interface and T1 hyperintensity) features to enable the detection of focal cortical dysplasia.39 By combining many parameters with machine learning techniques to classify lesional and non-lesional vertices, focal cortical dysplasia was detected in 14 of 24 MRI-negative patients.40 An automated classifier based on surface morphology and intensity gave 60% sensitivity to detect type II focal cortical dysplasia (three of seven with type IIA and six of eight with type IIB) that was not evident on visual reading, with no false-positive findings but with some extralesional clusters.41 Automated detection methods have a promising role in augmenting visual assessment, particularly with focal cortical dysplasia type IIB.
局灶性皮质发育不良可能与 VBM 未检测到的异常脑回和脑沟形态有关。基于表面的形态测量技术生成皮质表面的几何模型，这些模型允许测量皮质厚度等特征。这种技术可以扩展到分析许多形态学(皮质厚度，曲率和深度)和纹理(灰白质界面模糊和 T1高信号)特征，以便能够检测局灶性皮质发育不良。通过结合许多参数和机器学习技术来分类病变和非病变顶点，在24例 MRI 阴性患者中有14例检测到局灶性皮质发育不良。基于表面形态学和强度的自动分类器对检测 II 型局灶性皮质发育不良(IIA 型7例中有3例，IIB 型8例中有6例)具有60% 的敏感性，在视觉阅读中不明显，没有假阳性发现，但具有一些外部聚类。41自动化检测方法在增强视觉评估方面具有潜在的作用，特别是对于 IIB 型局灶性皮质发育不良。
An important caveat is that although advances in field strength, gradients, acquisitions, and post-acquisition processing and quantification will result in increased identification of subtle abnormalities that might underlie epilepsy, a detection rate of above 20–30% cannot be expected in individuals with no clear abnormalities on conventional MRI scans.42 Undoubtedly, some patients with focal epilepsy (eg, those with a neurochemical derangement) will not have a focal cerebral structural abnormality. In these patients, functional imaging, including perfusion and nuclear medicine techniques, could be used to infer the location of an epileptogenic network (see later). A further important caveat is that more sensitive methods will inevitably produce some spurious findings, which might include false-positive artifacts and true findings, such as increased T2 signal around the lateral ventricle, that are not relevant to the epilepsy. It is important, therefore, to apply so-called fuzzy logic by a sceptical expert to assessment of all imaging data and to interpret the findings in the context of clinical and EEG information.
一个重要的警告是，尽管在场强，梯度，获取和采集后处理和定量方面的进展将导致可能是癫痫的基础的微妙异常的识别增加，但是在常规 MRI 扫描没有明显异常的个体中，不能预期检出率超过20-30% 。毫无疑问，一些局灶性癫痫患者(例如神经化学紊乱)将不会有局灶性脑结构异常。在这些患者中，功能成像，包括灌注和核医学技术，可以用来推断致痫网络的位置(见后文)。另一个重要的警告是，更敏感的方法将不可避免地产生一些虚假的发现，其中可能包括假阳性伪影和真实的发现，如侧脑室周围 T2信号增加，这与癫痫无关。因此，重要的是应用所谓的模糊逻辑，由一个怀疑的专家来评估所有的影像数据，并解释在临床和脑电信息的背景下的发现。
Identifying the cerebral lateralisation of speech and the localisation of eloquent functions is crucial when planning surgical resections close to areas of the brain involved in these functions, so that the risk of creating new deficits can be taken into account when making a decision about surgery and the surgical approach can be planned to minimise the risk.
在计划接近涉及这些功能的大脑区域的手术切除时，确定语言的大脑偏侧化和雄辩功能的本地化是至关重要的，因此在决定手术时可以考虑产生新赤字的风险，并且可以计划手术方法以尽量减少风险。
fMRI can be used to map language networks in patients with epilepsy for clinical and research purposes. Various language tasks that activate anterior (ie, Broca's area) and posterior (ie, Wernicke's area) language areas have been used to establish patterns of typical and atypical language lateralisation.43 Verbal fluency, verb generation, and semantic decision tasks are used commonly for assessment of language in a clinical context, providing complementary information.44 In addition to visual reading of the numbers of activated voxels, the lateralisation index of activation in preselected regions of frontal and temporal lobes gives a quantitative measure of left–bilateral–right dominance that brings objectivity to decisions relating to epilepsy surgery and is useful for research studies. Conventional and adaptive thresholds and bootstrap techniques have been used; the latter has the advantage of being more specific and able to identify outliers.45
功能磁共振成像可以用来绘制癫痫患者的语言网络，用于临床和研究目的。激活前部(即 Broca 区域)和后部(即韦尼克区域)语言区域的各种语言任务已被用于建立典型和非典型的语言偏侧化模式。43语言流畅性，动词生成和语义决策任务通常用于评估临床语境中的语言，提供补充信息。44除了活化体素数量的视觉阅读之外，额叶和颞叶预选区域的激活偏侧化指数提供了左-双侧-右侧优势的定量测量，为与癫痫手术有关的决策带来客观性，并且对研究研究有用。采用了传统的和自适应的阈值和自举技术; 后者的优点是更具体，能够识别异常值
Individuals with left hemisphere epilepsy are more likely to have atypical language lateralisation than those with right hemisphere epilepsy.46 Individuals with left temporal lobe epilepsy and left language dominance recruit homologous right hemisphere areas for language processing, suggesting widespread language representation.47 Individuals with temporal lobe epilepsy are more likely to have atypical language lateralisation in Wernicke's area, whereas anterior language areas are more affected in those with frontal lobe foci.48 Many factors combine to affect language laterality. Left handedness is associated with an increased likelihood of a language shift to the right hemisphere in temporal lobe epilepsy, as is a left-sided focus, onset of epilepsy at 12–20 years, and absence of a genetic predisposition for left handedness.46, 49 Increased grey matter volume in language networks in the hemisphere contralateral to the epileptic focus suggests hard-wired compensatory mechanisms of reorganisation.50
左半球癫痫患者比右半球癫痫患者更可能有非典型的语言偏侧化。左半球脑颞叶癫痫症和左语优势的个体招募同源的右半球区域进行语言处理，这表明语言表征广泛存在。脑颞叶癫痫症患者更可能在韦尼克区域有非典型的语言偏侧化，而前语言区域在额叶病灶患者中受影响更大。许多因素共同影响语言偏侧性。左撇子与脑颞叶癫痫症语言转移到右半球的可能性增加有关，左侧焦点，12-20岁时癫痫发作，并且没有左撇子的遗传易感性。癫痫焦点对侧半球语言网络中灰质体积增加提示重组的硬连接补偿机制
Language lateralisation inferred from fMRI findings concurs with findings from the intracarotid amobarbital test (also known as the Wada test) in 80–90% of patients when using conjunction analysis of three language tasks.51 Concordance between fMRI and intracarotid amobarbital test findings is greatest for patients with right temporal lobe epilepsy with left language dominance, and lowest for patients with left temporal lobe epilepsy with left language dominance.52 The consensus in most epilepsy surgery centres is that fMRI language lateralisation can replace the intracarotid amobarbital test in most patients to establish hemispheric dominance. However, the latter might be needed when a patient cannot perform the fMRI task, if fMRI is contraindicated, and, in some cases, for the validation of atypical, inconclusive, or not clearly lateralised language activation on fMRI.53
从 fMRI 结果推断的语言偏侧化与80-90% 的患者在使用三种语言任务的联合分析时的颈动脉内阿莫巴比妥试验(也称为和田试验)的结果一致。51 fMRI 与颈动脉内阿莫巴比妥试验结果的一致性对于右侧脑颞叶癫痫症左侧语言优势的患者最高，对于左侧语言优势的患者最低。52大多数癫痫手术中心的共识是 fMRI 语言偏侧化可以取代大多数患者的颈动脉内阿莫巴比妥试验，以建立半球脑颞叶癫痫症优势。然而，当患者不能执行 fMRI 任务时，如果 fMRI 是禁忌的，并且在某些情况下，用于验证 fMRI 上非典型，不确定或不明确的侧向语言激活，则可能需要后者
Preoperative fMRI activation in response to a verbal fluency task in the middle and inferior frontal gyri predicts substantial decline in verbal naming after left temporal lobe resection, with good sensitivity but poor specificity.54 It is intuitive that a language activation task that primarily activates the part of the temporal lobe that is to be removed in surgery will be a better predictor of word-finding difficulties after temporal lobe resection than a task that primarily activates the adjacent frontal lobe. Auditory and visual naming tasks have promise in this regard and might enable more specific prediction of naming difficulties after anterior temporal lobe resection.55
术前 fMRI 激活响应中下额叶回的语言流畅性任务，预测左颞叶切除术后语言命名显着下降，敏感性好，特异性差[54]。直观的是，主要激活手术中将被切除的颞叶部分的语言激活任务将是一个更好的预测因子在颞叶切除后找词困难比主要激活相邻额叶的任务。听觉和视觉命名任务在这方面有希望，并可能使得更具体地预测颞叶前切除术后的命名困难
When a cortical resection is needed close to eloquent language cortex, the localisation inferred from language fMRI is not adequate to guide resection because areas that do not seem to be activated at the threshold used to display data might be necessary for language function, and areas that are activated might not be crucial. As a consequence, electrocortical stimulation or awake resections, or both, are necessary in such cases.56 Cortical language function can also be localised with navigated transcranial magnetic stimulation and the results mapped onto the individual's MRI scan. However, concordance with the standard of direct cortical stimulation was impaired in those with lesions.57 An active area of research is assessment of whether non-invasive language mapping with fMRI or transcranial magnetic stimulation might render direct cortical stimulation unnecessary.
当需要在雄辩的语言皮层附近进行皮层切除时，从语言 fMRI 推断的定位不足以指导切除，因为在用于显示数据的阈值处似乎不被激活的区域可能是语言功能所必需的，激活的区域可能不是关键的。因此，在这种情况下，皮层电刺激或清醒切除，或两者都是必要的。56皮层语言功能也可以通过导航经颅磁力刺激定位，并将结果映射到个人的 MRI 扫描上。然而，直接皮层刺激标准的一致性在病变患者中受到损害。57一个活跃的研究领域是评估使用 fMRI 或经颅磁力刺激的非侵入性语言映射是否可能使直接皮层刺激变得不必要。
Memory impairment commonly accompanies temporal lobe epilepsy and a clinical concern is the risk of temporal lobe surgery causing worsened memory. Verbal memory encoding activates a bilateral network including temporal, parietal, and frontal lobes. Greater left hippocampal activation for word encoding is correlated with better verbal memory in patients with left temporal lobe epilepsy.58 Visual memory encoding recruits a more widespread bilateral cortical network, and greater right hippocampal activation for face encoding is correlated with better visual memory in patients with right temporal lobe epilepsy.58 Functional reorganisation of networks involving extra-temporal and temporal structures for verbal-specific and visual-specific memory encoding suggests that compensatory mechanisms are in operation to mitigate the impaired function of the sclerotic hippocampus.59, 60
Verbal memory declines in a third of patients undergoing left temporal lobe resection and visual memory declines in a third of those who have right temporal lobe resection.58, 60, 61 The ability to predict this decline is important to be able to advise individual patients of their risks. Preoperative memory ability, age at onset of epilepsy, language lateralisation, and asymmetry of activation on fMRI for verbal and visual memory can be predictive of verbal memory decline after left anterior temporal lobe resection, but are less accurate predictors of visual memory decline after right anterior temporal lobe resection.58, 61 In a comparison of seven fMRI protocols, a verbal memory task showed the most consistent activation and was best able to discriminate between patients with left and right temporal lobe epilepsy,62 suggesting that fMRI assessment of verbal memory is useful for identifying abnormal temporal lobe function.
In individuals with left temporal lobe epilepsy, predominantly left-sided anterior hippocampal activation in response to a word encoding task was correlated with greater decline of verbal memory after left anterior temporal lobe resection.58 Conversely, predominantly left-sided posterior hippocampal activation was correlated with better verbal memory after resection.58 In those with right temporal lobe epilepsy, predominantly right-sided anterior hippocampal activation in response to face encoding was associated with greater decline of visual memory after right anterior temporal lobe resection, and predominantly right-sided posterior hippocampal activation was associated with superior visual memory after surgery. Memory activation patterns before surgery were the strongest predictor of verbal and visual memory loss as a result of anterior temporal lobe resection, and preserved function in the ipsilateral posterior hippocampus seems to help to maintain memory encoding after anterior temporal lobe resection.58 In another study, a clinically applicable fMRI verbal memory task that was used to assess the lateralisation index of memory and associated language functions in the medial temporal and frontal lobes was the best predictor of verbal memory decline after temporal lobe resection (figure 4), compared with language fMRI and clinical parameters.63 Replication of these findings is needed to establish whether this method would be suitable for widespread use.
在左侧脑颞叶癫痫症的个体中，主要是左侧前海马激活对单词编码任务的反应与左前颞叶切除术后语言记忆的更大下降相关。相反，主要是左侧后海马激活与切除后更好的语言记忆相关。在右侧脑颞叶癫痫症中，主要是右侧前海马激活对面部编码的反应与右前颞叶切除术后视觉记忆的更大下降相关，主要是右侧后海马激活与手术后优越的视觉记忆相关。手术前的记忆激活模式是颞叶前切除导致的言语和视觉记忆丧失的最强预测因子，同侧后海马中的保留功能似乎有助于在颞叶前切除后维持记忆编码。在另一项研究中，临床适用的 fMRI 言语记忆任务用于评估内侧颞叶和额叶中的记忆和相关语言功能的偏侧化指数是颞叶切除后言语记忆下降的最佳预测因子(图4) ，与语言 fMRI 和临床参数相比。需要复制这些发现来确定这种方法是否适合广泛使用。
Figure 4. Functional MRI for prediction of changes in verbal memory after temporal lobe surgery
图4。功能磁共振成像预测颞叶手术后言语记忆的变化
(A) Correlations between functional MRI activation in response to words remembered and postoperative verbal memory decline in patients with left TLE (n=23) and right TLE (n=27). In patients with both left TLE and right TLE, the surface-rendered whole-brain images (upper panel) show that left frontal activations were significantly correlated with greater postoperative verbal memory decline. No correlation was found in the right hemisphere in patients with left or right TLE. The sliced images (lower panel) show that predominantly left medial temporal lobe activations were significantly correlated with greater postoperative verbal memory decline in patients with left TLE. A similar correlation was not found for patients with right TLE. (B) Correlation of individual lateralisation indices for words remembered in the frontotemporal region (using an anatomical mask) in patients with left TLE (n=23) with change in list learning 4 months after left anterior temporal lobe resection (R2=0·43). Each circle represents one patient. The vertical red line shows the level of significant decline calculated by the reliable change index using control data. The horizontal dashed line shows a lateralisation index of 0·5 (left > right), with scores of ≥0·5 indicative of strong left lateralisation. Seven of eight patients who experienced a significant verbal memory decline had a lateralisation index of at least 0·5, which was the strongest predictor of postoperative verbal memory decline. TLE=temporal lobe epilepsy. Reproduced from Sidhu and colleagues,63 by permission of Wolters Kluwer Health.
(A)功能性磁共振成像激活对词汇记忆的反应与术后言语记忆下降的相关性在患者左(n = 23)和右(n = 27)。在左、右 TLE 患者中，表面呈现的全脑图像(上图)显示左额叶激活与术后语言记忆下降显著相关。在左右颞叶癫痫患者的右半球没有发现相关性。切片图像(下图)显示左侧颞叶内侧激活主要与左侧 TLE 患者术后语言记忆下降显著相关。右颞叶癫痫患者没有发现类似的相关性。(B)左颞叶前叶切除术后4个月(R2 = 0.43) ，左颞叶(n = 23)患者额颞区(使用解剖面具)记忆单词的个体偏侧化指数与列表学习变化的相关性。每个圆圈代表一个病人。垂直红线显示的水平显着下降的可靠变化指数计算使用控制数据。水平虚线显示偏侧化指数为0.5(左 > 右) ，分数≥0.5表示强烈的左侧化。8名患者中有7名经历了显著的言语记忆下降，其侧化指数至少为0.5，这是术后言语记忆下降的最强预测指标。TLE = 脑颞叶癫痫症。转载自 Sidhu 及其同事，经 Wolters Kluwer Health 许可，63。
fMRI with finger and foot tapping tasks can be used to identify the primary motor cortex, which is beneficial when planning intracranial EEG implantations and resections. fMRI generally gives results that are concordant with findings from cortical stimulation and high gamma electrocorticography.64 In patients with frontal lobe epilepsy, activation is reduced on the side of the focus after seizures. This finding implies that seizures affect motor circuitry, but does not suggest that the location of the primary area of activation is affected.65 Navigated transcranial magnetic stimulation has been used to map activations with a mean Euclidean separation from the direct site of invasive cortical stimulation of 11 mm (SD 4) for the hand and 16 mm (SD 7) for arm muscle representation areas, with locations within the same gyrus, thus giving an accuracy suitable for epilepsy surgical assessments.66 Resections close to motor cortex still need direct electrocortical stimulation mapping or for resections to be done while the patient is awake, or both, to minimise the risk of causing a lasting deficit.
功能性磁共振成像(fMRI)可以用手指和脚轻敲任务来识别初级运动皮质，这对计划颅内脑电图植入和切除是有益的。功能磁共振成像通常给出的结果与皮层刺激和高伽马皮层电图的结果一致。64在额叶癫痫患者中，癫痫发作后病灶侧的激活减少。这一发现意味着癫痫发作影响运动回路，但并不表明主要激活区域的位置受到影响。导航经颅磁力刺激已被用于绘制激活的平均欧几里得分离，手的直接侵入性皮层刺激部位为11mm (SD 4) ，手臂肌肉表征区域为16mm (SD 7) ，位于同一回路内，因此提供了适合癫痫手术评估的准确性。
Impaired brain function occurs not only if an eloquent area is damaged, but also if functional connectivity within and between eloquent areas is affected. Cognitive impairment has been reported in children with frontal lobe epilepsy in association with decreased functional frontal lobe connectivity, despite having intact fMRI activation in response to a working memory task, emphasising the effect of impaired functional networks on cognition.67 In adults with temporal lobe epilepsy, resting-state thalamo-temporal functional connectivity was associated with long-term memory performance, and thalamo-prefrontal functional connectivity was associated with short-term memory performance.68 A machine-learning-based analysis of resting-state functional connectivity has been proposed as a method to establish lateralisation of the seizure focus in temporal lobe epilepsy.69 Impaired connectivity in a network involving the anterior nucleus and pulvinar of the thalamus has been reported in temporal lobe epilepsy.70 Although fMRI studies of functional connectivity can be used to investigate the pathophysiology of epileptic networks, and hold promise for assisting with the prediction of epilepsy surgery outcome, the potential benefit for clinical studies of individual patients is not established.
脑功能受损不仅发生在雄辩区域受损的情况下，也发生在雄辩区域内部和之间的功能连接受到影响的情况下。尽管对工作记忆任务具有完整的 fMRI 激活，但额叶癫痫患儿的认知功能障碍与功能性额叶连通性降低相关，强调功能网络受损对认知的影响。在患有脑颞叶癫痫症的成年人中，静息状态下的丘脑-颞叶功能连接与长期记忆表现相关，丘脑-前额叶功能连接与短期记忆表现相关。基于机器学习的静息状态功能连接性分析已被提出作为建立癫痫发作焦点偏侧化脑颞叶癫痫症的一种方法。丘脑前核和脑颞叶癫痫症的网络连接受损已有报道。尽管功能连接性的 fMRI 研究可用于研究癫痫网络的病理生理学，并有望协助预测癫痫手术结果，但个体患者临床研究的潜在益处尚未确定。
fMRI can be used to identify eloquent cortex, but surgical damage to white matter connections must also be avoided to prevent postoperative neurological deficits. Tractography data derived from diffusion-weighted MRI, usually diffusion tensor imaging, enables the non-invasive in-vivo delineation of white matter tracts.
Most clinical research into white matter tracts in patients with epilepsy has focused on the optic radiation because damage to Meyer's loop during anterior temporal lobe resection can cause a visual field deficit that can preclude driving.71 The extent of resection and distance from Meyer's loop to the temporal pole on preoperative tractography are predictive of the risk of a visual field deficit,72 and tractography therefore can be used to assist with surgical planning and risk stratification.73 Display of tractography data during surgery with correction for brain shift using intraoperative MRI reduces the risk of a visual field deficit (figure 5).74, 75
Figure 5. Optic radiation tractography for surgical guidance
图5。光学放射性纤维束成像手术指导
(A) Optic radiation tractography data can be superimposed on the coronal fluid-attenuated inversion recovery MRI scan to show the relation with a cavernoma to aid surgical planning and (B) can also be displayed in three-dimensional renderings. Panels A and B reproduced from Winston and colleagues,74 by permission of John Wiley & Sons. (C) Tractography data can then be displayed on the operating microscope display in real time for surgical guidance. Panel C adapted from Winston and colleagues,75 by permission of Wolters Kluwer Health.
Delineation of the corticospinal tract in patients undergoing frontal lobe surgery is beneficial, particularly in children for whom fMRI is challenging. Localisation inferred by tractography gives similar results to invasive electrical stimulation mapping and can be used to predict the risk of postoperative motor deficits.76 Much work on the corticospinal tract has been done in patients with gliomas, which can readily be translated to patients with epilepsy.
More limited data are available on the arcuate fasciculus, which might be a result of a weaker association between damage and postoperative outcomes arising from the multiplicity of language pathways. Nevertheless, tractography might have a role in the assessment of paediatric patients for epilepsy surgery.77 Moreover, tractography of all three tracts with intraoperative MRI was beneficial in reducing the risk of deficits after ganglioglioma surgery in adults.78
弓形神经束的数据更为有限，这可能是由于语言通路的多样性导致损伤与术后结果之间的关联性较弱。尽管如此，纤维束成像可能在评估儿童癫痫手术患者中起作用[77]。此外，术中 MRI 对所有三个纤维束的纤维束成像有助于降低成人神经节胶质瘤手术后缺陷的风险
However, tractography has limitations. The tracts obtained are assumed to be a faithful representation of the underlying anatomy, but spatial resolution and modelling limitations result in inaccuracy. Different algorithms give varying results.79 Data derived from diffusion-weighted images are distorted compared with anatomical scans, and their use during surgery ideally involves correction for brain shift with intraoperative MRI. Although intraoperative MRI is helpful, cost and availability are restrictive. Future developments should include better diffusion models, automation of tractography, its use with standard neuronavigation systems, and correction for brain shift using alternative techniques such as ultrasound.
然而，纤维束成像有其局限性。所获得的束被认为是下层解剖的忠实表示，但是空间分辨率和模型的局限性导致了不准确性。不同的算法给出不同的结果。79弥散加权图像得出的数据与解剖扫描相比是扭曲的，并且它们在手术中的使用理想情况下包括术中 MRI 校正脑移位。虽然术中 MRI 是有帮助的，但成本和可用性是有限的。未来的发展应该包括更好的扩散模型，纤维束成像的自动化，与标准的神经导航系统一起使用，以及使用超声波等替代技术校正大脑移位。
If MRI does not show a structural lesion that is concordant with clinical and EEG data, further investigations are necessary to infer the localisation of the epileptic network (figure 1).4
如果 MRI 没有显示与临床和脑电图数据一致的结构性病变，则需要进一步的研究来推断癫痫网络的定位(图1)
PET imaging is an important investigation for non-invasively localising epileptogenic brain regions in MRI-negative focal epilepsies, in patients with more than one abnormality, or if MRI and ictal EEG are not concordant.
18F-FDG PET has been used for epilepsy surgery assessments since before the advent of MRI. The wide availability of the method in oncology centres, and its use as an interictal investigation, results in 18F-FDG PET generally being used in preference to ictal SPECT (see later) in the epilepsy surgery pathway.
Regional cerebral hypometabolism identified with 18F-FDG PET often has a wider distribution than that of the seizure focus, which can represent both the focus and projection areas of seizure activity (figure 6).80 This absence of specificity makes surgical decisions on the extent of resective surgery difficult. However, in a study of post-operative outcomes, patients who were seizure free after surgery had more of the hypometabolic area resected than did individuals who continued to experience seizures.81
Figure 6. 18F-fluorodeoxyglucose PET imaging for the localisation of epileptogenic brain regions in MRI-negative focal epilepsy
图6.18 F- 氟脱氧葡萄糖 PET 显像对 MRI 阴性局灶性癫痫致痫脑区的定位
18F-fluorodeoxyglucose PET scan showing left temporal hypometabolism in a 32-year-old man with normal MRI and left temporal lobe epilepsy (A, axial slice; B, coronal slice). (C) Results of a statistical voxel-based comparison of surface-rendered glucose uptake in the patient, compared with a set of control data (using Neurostat-3D SSP software). An area of hypometabolism (green) is evident in the left temporal lobe (right panel). The patient became seizure free after left temporal lobe resection. Reproduced from Rathore and colleagues,80 by permission of Elsevier.
The main advantage of clinical PET imaging for its future use is that it is versatile, allowing not only mapping of in-vivo processes, such as perfusion and metabolism, but also the quantification of the distribution of radiolabelled markers with concentrations in the nanomolar range. This versatility depends on the availability of a cyclotron and radiochemistry laboratory. For tracers labelled with 11C, which has a half-life of 20 min, the cyclotron and radiopharmacy laboratory has to be in the same location as the scanner, which greatly reduces the applicability outside a few centres. 18F has a half-life of 2 h, so production can be at a distant facility and the tracer shipped to the scanner.
临床 PET 成像用于未来使用的主要优点是它是多功能的，不仅允许对体内过程(如灌注和代谢)进行映射，而且还可以定量放射性标记标记物在纳摩尔范围内的浓度分布。这种多功能性取决于回旋加速器和放射化学实验室的可用性。对于用11C 标记的示踪剂，其半衰期为20分钟，回旋加速器和放射性制药实验室必须与扫描仪位于同一位置，这大大降低了几个中心之外的适用性。18F 的半衰期为2小时，因此生产可以在一个遥远的工厂进行，并将示踪剂运送到扫描仪上。
Several PET receptor ligands have been used to assess neurotransmitter systems involved in the pathophysiology of epilepsy. 11C-flumazenil PET imaging can be used to detect reductions in GABAA receptor binding, but with limited success in localisation of epileptic foci in patients with normal MRI.82 In a group of patients with difficult-to-treat focal epilepsies, reduced 11C-flumazenil binding was found in the temporal piriform cortex, which was associated with increased seizure frequency.83 This finding raised the possibility of the existence of a common network and that removal of the temporal piriform cortex might be relevant for achieving postoperative seizure freedom.83 18F-flumazenil is, in some centres, more widely available than 11C-flumazenil and thus might be more useful in understanding the clinical benefit of benzodiazepine receptor imaging.84
一些 PET 受体配体已被用于评估神经递质系统参与癫痫的病理生理学。11C- 氟马西尼 PET 成像可用于检测 GABAA 受体结合的减少，但在 MRI 正常的患者癫痫灶定位成功率有限。在一组难以治疗的局灶性癫痫患者中，颞梨状皮质11C- 氟马西尼结合减少，这与癫痫发作频率增加有关。这一发现提高了存在共同网络的可能性，并且切除颞梨状皮质可能与实现术后癫痫发作自由有关。在一些中心，18F- 氟马西尼比11C- 氟马西尼更广泛地获得，因此可能更有助于理解苯二氮卓受体成像的临床益处。84
α-11C-methyl-L-tryptophan was considered originally to be a marker of serotonin synthesis, but uptake of this tracer in PET imaging is now thought to be an indicator of altered excitatory aminoacid concentrations and inflammatory pathways. An increased uptake can be used to reliably identify an epileptogenic tuber in patients with tuberous sclerosis when more than one tuber is present.85 If replicated, this imaging method could be very useful in this context and in the identification of abnormalities in individuals with normal MRI.
Α-11C- 甲基 -L- 色氨酸最初被认为是5-羟色胺合成的标志物，但是在 PET 成像中该示踪剂的摄取现在被认为是兴奋性氨基酸浓度和炎症途径改变的指标。增加的摄取可以用来可靠地识别一个癫痫结节性硬化症患者的多个块茎存在。如果复制，这种成像方法可能是非常有用的，在这种情况下，并在鉴别异常的个人与正常的 MRI。
SPECT imaging can provide information about dynamic changes in cerebral perfusion before, during, and after a seizure. Timing of injection and duration of the seizure are important for correct interpretation of the SPECT images, because delayed injection can result in a variable pattern of blood flow changes as the seizure evolves and propagates. True ictal SPECT shows an area of hyperperfusion in the epileptogenic region, surrounded by an area of hypoperfusion that might be caused by shifting of blood flow to the seizure focus or might represent an inhibitory zone that limits the seizure spread.86 Limitations of ictal SPECT include the complex logistics needed, the fact that only one dataset representing cerebral blood flow is obtained, and timing issues. After intravenous injection, the tracer takes at least 40 s to reach the brain, cross the blood–brain barrier, and become fixed. Thus, with a short seizure of less than 30 s, the image of cerebral blood flow will inevitably be post-ictal rather than ictal, and even with a longer seizure, areas of propagation rather than onset will be visualised. Ictal SPECT in the presurgical assessment pathway is most useful in patients with refractory focal epilepsy who have MRI that is normal or discordant with clinical and EEG data, and to assist with formulation of a hypothesis of seizure onset localisation that can be tested with intracranial EEG. Ictal SPECT imaging would not usually be used to directly support a resection.
SPECT 显像可以提供癫痫发作前、发作中和发作后脑灌注动态变化的信息。注射的时机和癫痫发作的持续时间对正确解释 SPECT 图像很重要，因为延迟注射可能导致癫痫发作进展和传播时血流变化的可变模式。真正的发作性 SPECT 显示癫痫发作区域的高灌注区域，被可能由血流向癫痫发作焦点转移引起的低灌注区域包围，或者可能代表限制癫痫发作扩散的抑制区域。发作性 SPECT 的局限性包括所需的复杂物流，事实上只有一个代表脑血流量的数据集被获得，以及时间问题。在静脉注射后，示踪剂至少需要40秒才能到达大脑，穿过血脑屏障，并变得固定。因此，如果癫痫发作时间短于30秒，脑血流图像将不可避免地是发作后而不是发作，即使癫痫发作时间较长，也将显示传播区域而不是发作区域。术前评估途径中的发作性 SPECT 对于具有与临床和脑电图数据正常或不一致的 MRI 的难治性局灶性癫痫患者最有用，并且有助于制定可以用颅内脑电图测试的癫痫发作发作定位的假设。发作性 SPECT 显像通常不能直接用于支持手术切除。
Simultaneous scalp EEG-fMRI recordings can be used to map haemodynamic changes associated with interictal epileptic discharges with 30–40% sensitivity87 and might be useful for planning intracranial implantations,88 with widespread abnormalities taken as a warning sign of poor outcome from resection.89 If an individual has frequent seizures, an ictal EEG-fMRI recording can be obtained. Focal or widespread haemodynamic changes are often seen before the onset of seizures on scalp EEG recordings, suggesting that additional brain networks might be involved before seizure onset on scalp EEG,90 and highlighting the low sensitivity of scalp EEG.91 In generalised epilepsies, EEG-fMRI has shown involvement of cortico-subcortical networks during generalised spike wave discharges.92 The clinical role of scalp EEG-fMRI is that localisation of identified ictal and interictal networks can be useful during presurgical assessment, helping with the design of intracranial EEG sampling strategies and showing whether there is likely to be a poor outcome, which may dissuade the clinician from proceeding.
同时头皮脑电图-功能磁共振成像记录可用于绘制与发作间癫痫放电相关的血流动力学变化，敏感性为30-40% [87] ，并且可能有助于规划颅内植入[88] ，广泛的异常被认为是切除不良结果的警告标志[89]。如果个体癫痫发作频繁，可以获得发作性脑电图-功能磁共振成像记录。在头皮脑电图记录癫痫发作之前，常常可以看到局灶性或广泛的血流动力学改变，这表明额外的脑网络可能在头皮脑电图癫痫发作之前参与[90] ，并突出了头皮脑电图的低敏感性.91在全身性癫痫中，EEG-fMRI 显示皮质-皮层下网络参与了全身性的尖峰波放电[92]。头皮脑电图-fMRI 的临床作用是在术前评估期间确定发作和发作间网络的定位可能是有用的，有助于设计颅内脑电图采样策略，并显示是否可能存在不良的结果，这可能会阻止临床医生继续进行。
Simultaneous recording of intracranial EEG and fMRI is possible93 and can show haemodynamic alterations occurring before the first detected EEG changes, suggesting the presence of a distributed network and that the implanted electrodes are at a distance from the site of epileptic activity.94
同时记录颅内脑电图和功能磁共振成像是可能的[93] ，并且可以显示在第一次检测到的脑电图变化之前发生的血液动力学改变，表明存在分布式网络，并且植入的电极距离癫痫活动的部位
ESI, based on reconstruction of electrical activity derived from high-density scalp EEGs, can produce more prolonged recordings than is possible with EEG-fMRI or MEG and can be used to identify the irritative zone generating interictal epileptic activity. A large number of channels (eg, 128) are needed for high-quality ESI. The results need to be computed with the individual's MRI data. Inaccurate modelling of electromagnetic field propagation can result in errors. Comparison with subsequent intracranial EEGs has shown a median separation of 13–16 mm between the ESI and the intracranial contact showing maximum discharges.95 Resection of the interictal ESI maximum has been associated with a good surgical outcome,96 and the concordance of an ESI focus with an MRI lesion has been associated with a 92% chance of good seizure outcome after resection.97 If replicated, these findings suggest a role for ESI early in the epilepsy surgery pathway, with the possibility of other investigations becoming redundant.
MSI, based on a combination of magnetoencephalography (MEG) and MRI data, when used to map interictal epileptic activity, seems promising in retrospective studies, with higher seizure freedom rates if a computed dipole was concordant with other data than if dipoles were discordant or non-specific.98, 99 Electrical and magnetic source localisation are complementary and their combination improves the accuracy of source localisation and identification of propagated activity.100
In practical terms, EEG-fMRI, ESI, and MSI are used to map interictal epileptic activity, with a small chance of including ictal activity, the possibility being greater with ESI because more prolonged recordings are feasible. The roles of these techniques in the presurgical algorithm have not yet been established. For individuals with concordant MRI and ictal and interictal video EEG findings, further data are redundant. The patients who stand to benefit are those for whom there is not a clear surgical solution and who would need intracranial EEG to define the epileptogenic zone. Data from additional techniques can help to generate a hypothesis that can be tested with intracranial EEG and to identify patients in whom abnormalities are widespread and in whom invasive studies should not be done. Prospective studies to assess the role of these techniques in the presurgical algorithm will be challenging because the three techniques are not likely to be developed to a similar level in any one centre, and a multicentre study with at least 12 months of postoperative follow-up would be needed. Each method would probably show some usefulness, with all three contributing to localisation of seizure source in some cases, and any one technique being uniquely helpful in a subset of patients.
实际上，EEG-fMRI，ESI 和 MSI 用于绘制发作间期癫痫活动，包括发作活动的机会很小，ESI 的可能性更大，因为更长的记录是可行的。这些技术在术前算法中的作用尚未确定。对于具有一致 MRI 和发作期及发作间期视频脑电图表现的个体，进一步的数据是多余的。有可能受益的患者是那些没有明确的手术方案的患者，他们需要颅内脑电图来确定致痫区域。来自其他技术的数据可以帮助产生一个假设，可以用颅内脑电图进行检测，并确定哪些患者的异常是普遍存在的，哪些患者不应该进行侵入性研究。评估这些技术在术前算法中的作用的前瞻性研究将是具有挑战性的，因为这三种技术不太可能在任何一个中心发展到相似的水平，并且需要至少12个月的术后随访的多中心研究。每种方法都可能显示出一些有用性，在某些情况下，这三种方法都有助于癫痫发作源的定位，而且任何一种技术都对一部分患者有独特的帮助。
In 20–30% of candidates for epilepsy surgery, intracranial EEG is needed to define the epileptogenic zone.101 Increasingly, this is accomplished with stereotactic placement of several (ie, 12–20) depth electrodes (stereoelectroencephalography; SEEG). SEEG electrodes can be used to record from a 1 cm core around the cerebral entry point to the distal end (ie, target), which can be placed in the hippocampus, amygdala, or midline or inferior neocortex. Electrode implantation carries a risk of haemorrhage, neurological deficit, and infection.102 Preoperative planning of electrode trajectories using multimodal imaging, defining deep and superficial targets and skull entry points, can minimise implantation risk by ensuring that the electrodes avoid critical structures, particularly arteries and veins, and contact with other electrodes. Precise planning can also improve the efficiency of the recording by ensuring that electrode contacts sample grey rather than white matter. At present, standard clinical practice for planning electrode trajectories involves manual assessment of individual trajectories in series, which is a time-consuming and complex task that requires the integration of information across many imaging methods (figure 7). Optimisation of several parameters for each trajectory is necessary to reach the target, avoid critical structures, and obtain a suitable entry angle through the skull, and the different trajectories need to be adjusted to maximise grey matter sampling and avoid conflicts between electrodes. When placing a new electrode, adjustment of previously planned trajectories might be needed, making the planning process even more time-consuming.
在20-30% 的癫痫手术候选者中，需要颅内脑电图来确定致痫区域。101越来越多地通过立体定向放置几个(即12-20)深度电极(立体脑电图; SEEG)来完成。SEEG 电极可用于从大脑入口点周围的1厘米核心记录到远端(即目标) ，其可以放置在海马，杏仁核或中线或下新皮层中。电极植入具有出血，神经功能缺陷和感染的风险.102使用多模式成像对电极轨迹进行术前规划，确定深层和浅层目标以及颅骨入口点，可以通过确保电极避免关键结构，特别是动脉和静脉，并与其他电极接触来最小化植入风险。精确的计划也可以通过确保电极接触样品灰色而不是白色物质来提高记录的效率。目前，规划电极轨迹的标准临床实践涉及连续手动评估个体轨迹，这是一项耗时且复杂的任务，需要整合多种成像方法的信息(图7)。为了达到目标，避免关键结构，并通过头骨获得合适的进入角度，需要优化每个轨迹的几个参数，并且需要调整不同的轨迹以最大化灰质采样并避免电极之间的冲突。当放置一个新的电极时，可能需要调整先前计划的轨迹，使得计划过程更加耗时。
Figure 7. Integration of multimodal three-dimensional imaging in the epilepsy surgery pathway
图7。多模式三维成像在癫痫手术路径中的整合
Stereo-EEG implantation plan. Each electrode is depicted in a separate colour. All images are taken from the left posteriolateral direction. (A) Veins (blue) extracted from gadolinium-enhanced T1-weighted MRI and arteries (red) extracted from CT angiogram. (B) A lesion identified from T2-weighted FLAIR MRI (purple) and motor (green) and language (orange) regions identified from functional MRI. (C) The lesion and motor and language regions in (B) are shown on a volume-rendered T1-weighted MRI. FLAIR=fluid-attenuated inversion recovery.
立体脑电图植入计划。每个电极被描绘成一个单独的颜色。所有图像均从左后外侧方向拍摄。(A)从钆增强 T1加权 MRI 提取的静脉(蓝色)和从 CT 血管造影提取的动脉(红色)。(B)从功能性 MRI 鉴定的 T2加权 FLAIR MRI (紫色)和运动(绿色)和语言(橙色)区域鉴定的病变。(C)(B)中的病变和运动和语言区域显示在体积呈现的 T1加权 MRI 上。流体衰减反转恢复。
Recently, substantial progress has been made in the development of semi-automated computer-assisted planning software that markedly reduces the planning time by calculating quantitative measures of trajectory suitability. These measures can be used to select the best trajectory or to inform manual trajectory selection.103, 104, 105, 106 This planning requires the integration of multimodal imaging data, with each single method being combined together into a patient-specific three-dimensional map of the brain. The most crucial data are from CT to show the skull surface, T1-weighted MRI for the grey matter map, and magnetic resonance angiography, CT angiography, or T1-weighted MRI with gadolinium enhancement to show the arteries and veins. Different areas of interest indicated by fMRI, PET, or SPECT imaging can also be added to this three-dimensional map and included in the planning of different trajectories. Automatic solutions were recently assessed, showing the potential of these approaches in clinical settings.107
最近，在开发半自动计算机辅助规划软件方面取得了重大进展，该软件通过计算轨道适合性的定量测量，显著地减少了规划时间。这些措施可用于选择最佳轨迹或通知手动轨迹选择.103,104,105,106这一规划需要整合多模式成像数据，将每个单一方法结合在一起成为患者特定的大脑三维地图。最关键的数据来自于显示颅骨表面的 CT，用于灰质图的 T1加权 MRI，以及磁共振血管造影术、 CT 血管造影，或者用于显示动脉和静脉的 t1加权 MRI。功能磁共振成像、 PET 或 SPECT 成像显示的不同感兴趣区域也可以添加到这个三维地图中，并包括在不同轨迹的规划中。最近对自动化解决方案进行了评估，显示了这些方法在临床环境中的潜力
After intracranial electrodes have been placed, seizures can be documented with simultaneous videoing of the patient and EEG recording from the intracranial electrodes. Signals from the electrode contacts that record the earliest seizure activity are analysed, as is the subsequent spread of the activity. The area to be resected is decided after identification of the epileptogenic zone, taking into account the following: any structural lesion; the location of eloquent cortex, as inferred from fMRI and precisely located with electrical stimulation studies; crucial white matter tracts visualised with tractography; the major arteries and veins; and the location of any previous craniotomy and burr holes. Planning the surgical approach and the extent of the resection is particularly challenging if the epileptogenic zone is not located on the convexity of the cerebral hemisphere or if there is no evident lesion. The use of multimodal three-dimensional imaging to assist this planning has substantial promise, but one must keep in mind that all imaging and registration has the potential for some error and does not obviate the need for expert surgical technique.
在放置颅内电极后，可以同时记录病人的癫痫发作和颅内电极的脑电图记录。分析记录最早癫痫发作活动的电极接触信号，以及随后癫痫活动的传播。要切除的区域是在确定致痫区域之后决定的，考虑到以下因素: 任何结构性损伤; 雄辩的皮层的位置，如从 fMRI 推断的并精确定位于电刺激研究; 用纤维束成像显示的关键白质束; 主要动脉和静脉; 以及任何以前的开颅术和钻孔的位置。如果癫痫发作区域不在大脑半球的凸面上，或者没有明显的病变，则规划手术入路和切除范围尤其具有挑战性。使用多模式三维成像来协助这个计划有很大的希望，但是必须记住，所有的成像和注册都有可能出现一些错误，并不排除对专家手术技术的需要。
Over the next decade, we anticipate increased availability of 7 T clinical MRI scanners with enhanced sensitivity and improved imaging technology, and development of new magnetic resonance contrasts and analyses that will improve detection of subtle lesions that underlie refractory focal epilepsies and that might be amenable to surgical treatment. With the implementation of uniform protocols for acquisition and processing, we expect that computerised analysis of the much larger datasets than are acquired at present will become standard, to achieve data reduction and detection of suspicious areas of focal abnormality for review by clinicians. Greater sensitivity is likely to be accompanied by reduced specificity; thus, thorough assessment of the relevance of possible abnormalities will be essential. High-field MRI of ex-vivo cerebral resection specimens will allow detailed MRI–histological correlation and has the potential to inform optimisation of MRI sequences for in-vivo use and identification and prediction of the nature of abnormalities. Integration of several structural and functional imaging datasets will become routine and will inform clinical decision making in the presurgical pathway, so that the risk–benefit ratio can be quantified and optimised for individual patients.
在未来十年，我们预计7 t 临床 MRI 扫描仪的可用性将增加，其灵敏度和成像技术将得到提高，新的磁共振对比和分析的发展将改善难治性局灶性癫痫的微妙病变的检测，并可能适合手术治疗。随着采集和处理统一协议的实施，我们预计对比目前获得的大得多的数据集的计算机化分析将成为标准，以实现数据减少和检测可疑的焦点异常区域，供临床医生审查。更高的敏感性可能伴随着特异性的降低; 因此，彻底评估可能的异常的相关性将是至关重要的。体外脑切除标本的高场 MRI 将允许详细的 MRI 组织学相关性，并有可能为体内使用的 MRI 序列的优化以及异常性质的识别和预测提供信息。整合几个结构和功能成像数据集将成为常规，并将通知临床决策在手术前途径，以便风险-收益比可以量化和优化个体患者。
We searched PubMed for English language articles published between Jan 1, 2005, and Nov 1, 2015, with the search terms “epilep*” and one or more of “MRI”, “fMRI”, “functional MRI”, “PET”, “SPECT”, “MEG”, “electric* source imaging”, “EEG”, “DTI”, “diffusion MRI”, and “surgery”. We also included key earlier references from the authors' files. We selected reports for inclusion in this paper that we judged to be most relevant to clinical practice.
我们搜索了 PubMed 在2005年1月1日至2015年11月1日期间发表的英文文章，搜索词“ pilep *”和一个或多个“ MRI”，“ fMRI”，“功能性 MRI”，“ PET”，“ SPECT”，“ MEG”，“电 * 源成像”，“ EEG”，“ DTI”，“扩散 MRI”和“手术”。我们还包括了作者文件中早期的关键引用。我们选择报告纳入本文，我们认为是最相关的临床实践。
Contributors
投稿人
JSD, GPW, MJK, and SO did the literature searches, interpretation, writing, and editing of this Review.
JSD、 GPW、 MJK 和 SO 对本评论进行了文献检索、解释、撰写和编辑。
Declaration of interests
利益申报书
JSD has received personal fees from Eisai and non-financial support from Medtronic and has a patent pending for computer-assisted planning for neurosurgery. MJK has received personal fees from General Electric for PET tracer development, and from UCB, BIAL, and Eisai for antiepileptic drug development. SO has received grants from General Electric, Siemens, IXICO, MIRADA Medical, and IcoMetrix, and has a patent pending for computer-assisted planning for neurosurgery. GPW declares no competing interests.
JSD 从卫材公司收取个人费用，从美敦力公司获得非财政支持，并拥有一项正在申请的神经外科计算机辅助规划专利。MJK 收到了来自通用电气 PET 示踪剂开发的个人费用，以及来自 UCB、 BIAL 和 Eisai 的抗癫痫药物开发的个人费用。SO 公司获得了通用电气、西门子、 IXICO、米拉达医疗集团(miRADA Medical)和 IcoMetrix 公司的资助，并获得了神经外科计算机辅助规划的专利。GPW 宣布没有竞争利益。
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