发作期^18F—FDG PET显像对癫痫灶的定位价值

为评价发作期１８Ｆ脱氧葡萄糖（ＦＤＧ）ＰＥＴ显像在癫痫灶定位中的价值，对１５２例癫痫患者进行了发作期１８ＦＦＤＧＰＥＴ检查，并与发作间期图像比较。结果１５２例发作间期示低代谢区患者发作期均呈高代谢，其中６５例（４２８％）为明显高代谢，８７例（５７２％）为相对高代谢。８０例高代谢灶局限于单叶，７２例多发高代谢灶患者中４９例位于相邻近区域。发作期结合发作间期检查，可排除非致痫灶性低代谢病变和癫痫发作过程中痫性活动的播散，提高癫痫灶定位的特异性。     

发作期SPECT脑血流灌注显像和VEEG在癫痫灶定位诊断中的一致性

目的 探讨癫痫发作期SPECT脑血流灌注显像和视频脑电图（VEEG）在致痫灶定位中的一致性.方法 选择VEEG监测异常的癫痫患者45例,当患者出现临床发作和（或）脑电图出现典型癫痫波时30 s内注入锝-双半胱乙酯（^99Tc^m-ECD）,30 min后行脑血流灌注断层显像.比较癫痫发作期SPECT脑血流灌注显像和VEEG在癫痫定位诊断中的一致性,对部分性发作和全面性-强直阵挛发作患者发作期SPECT和VEEG定位的一致性进行卡方检验.结果 45例癫痫患者中,发作期SPECT定位阳性率为93.3％（42/45）,均表现为高血流灌注灶,其中40例（95.2％）表现为单叶局限性高灌注,2例（4.8％）表现为多个病灶高灌注.VEEG监测结果为：31例患者VEEG表现为局灶性异常放电,明确定位达68.9％（31/45）,各导联同步对称性异常放电不能定位者占所有患者的31.1％（14/45）.比较二者定位结果发现,对于部分性发作的患者,发作期SPECT和VEEG定位的一致性为83.9％（26/31）;对于全面性-强直阵挛发作的患者,VEEG表现为各导联同步对称性异常放电,而发作期SPECT则显示为孤立高血流灌注灶,故二者定位无一致性.部分性发作和全面性-强直阵挛发作患者发作期SPECT和VEEG定位的一致性差异有统计学意义（χ^2=24.478,P＜0.05）.结论 发作期SPECT脑血流灌注显像和VEEG在癫痫灶定位诊断中的一致性与癫痫发作类型相关.对于部分性发作的癫痫患者二者联合定位可指导手术治疗;而对于全面性-强直阵挛发作患者,发作期SPECT脑血流灌注显像和VEEG联合定位无一致性,需借助于其他检查方法方可明确定位.     

^18F—FDG PET脑显像在癫痫图型，病灶定位及预后预测中的价值

目的 分析各种癫痫患者的^18F－脱氧葡萄糖（FDG）PET图像与致痫灶的关系,以期术前较准确地定位,选择手术适应证和预测疗效。方法 73例癫痫患者（男51例,女22例,平均年龄23．3岁）行FDG PET脑显像,并与同期脑电图和MRI结果进行比较,40例进行了手术疗效随访,其中8例术后复查了FDG PET,并比较FDG PET,视频脑电图（VEEG）,MRI对致痫灶术前定位的准确性及脑代谢改变的不同图型与手术疗效的关系,结果（1）72 例癫痫患者发作间期皮层局灶为低代谢表现,仅1例部分癫痫持续状态者表现出发作期的高代谢。（2）FDG PET病变定侧率高于VEEG,低代谢灶检出率高于MRI,（3）40例手术患者中,属于Engels疗效分级I,II级的30例手术切除部位应为确定的致痫灶,FDG PET＜VEEG与MRI定侧定位准确性分别为93．3％,73．3％,53．3％,经X2检验,差异有显著性（P＜0．05）,（4）单侧颞叶低代谢手术效果好;对部分双侧颞叶低代谢者,切除其代谢减低更严重的一侧,发作也会改善,颞叶外癫痫手术效果不如颞叶癫痫好,病灶局限者,手术效果优于伴有其他部位皮层代谢改变者：单侧多脑叶代谢改变者,半大脑切除术效果好;双侧大脑多脑叶弥漫性病变者,手术效果差。结论 FDG PET对癫痫灶定位的灵敏度和准确性优于VEEG和形态学影像技术。FDG PET的代谢图形可帮助临床医生确定病灶部位,选择手术适应证和预测疗效。     

脑灌注显像定位致痫灶与皮层脑电图、术中和病理所见比较

目的：探讨SPECT脑灌注显像定位致痫灶的价值。方法：选择拟手术治疗的药物难治性部分性癫痫和其他癫痫患者23例，在发作间期和发作期分别进行SPECT脑灌注显像，用皮层脑电图（EcoG)手术和术后病理检查进行验证。结果：用EcoG探查SPECT显示病灶区，23例皆存在典型的尖慢波和棘尖波发放，发作期的局灶性放射性增高区和EcoG所示的异常电话动范围更匹配。痫波起源于相应区域的大脑皮层，而不是增厚和粘连蛛网膜或肿瘤本身，结论：SPECT脑灌注显像有助于识别致痫灶的位置，大小，血运和功能状态，对术前制定治疗方案有一定的指导作用。     

癫痫不同时期脑血流灌注显像动态观察在致痫灶定位诊断中的应用

目的 探讨癫痫发作不同时期脑血流灌注显像的动态观察对致痫灶定位的价值.资料与方法 回顾性分析20例行2次及以上脑血流灌注显像癫痫患者的临床资料,观察癫痫发作不同时期致痫灶区脑血流灌注变化情况;对照术后病理及临床随访结果分析多时相显像对致痫灶的定位效能.结果 本组患者中,发作期、发作后及发作间期显像分别占34.1％、20...     

美解眠介入脑血流显像对癫痫病灶的定位研究

目的：研究美解眠介入SPECT脑血流显像对癫痫病灶的定位。材料和方法：将药物诱发脑电图技术与^99mTc—ECD SPECT脑血流显像相结合建立美解眠介入亚临床发作脑血流显像并对14例局限性癫痫患者(8例经外科手术切除癫痫病灶)进行了发作间期和亚临床发作期脑血流显像比较研究．结果：亚临床发作期癫痫病灶脑血流平均较间期增加12．65%．10／14例增加超过5%，8／14例增加超过10%．最多增加超过31%．图像比较以亚临床发作期病灶血流出现反转和填充较有意义．结论：本方法可克服发作期显像不易及时注入显像剂的缺陷。     

顽固性癫痫发作间期PET/CT的显像研究

目的探讨顽固性癫痫患者在发作间期PET／CT显像对癫痫灶定位的诊断价值,以指导手术治疗。资料与方法对28例顽固性癫痫患者,行发作间期的^18F—FDG PET／CT显像。对其中的21例癫痫灶较局限的患者行癫痫灶或颞前叶切除,术中行皮层脑电图（ECoG）或深部脑电图（DEEG）描记,以检测其特异性,术后进行随访。结果28例顽固性癫痫患者中,经PET／CT显像有25例显示出低代谢灶,敏感性为89．3％（25／28）。21例手术患者经随访1年以上,癫痫发作消失者18例。结论PET／CT脑显像对癫痫患者的术前定位具有重要价值。     

46例癫痫患者发作间期~(18)F-FDG PET显像结果分析

目的　探讨18F 脱氧葡萄糖 (FDG)PET对发作间期癫痫灶的诊断价值。方法　 4 6例癫痫患者于发作间期进行CT和 (或 )MRI、头皮EEG及18F FDGPET检查。结果　 4 6例患者中 86 95 %(40例 )PET显像有异常代谢灶 ,其中低代谢灶 3 1例 ,高代谢灶 9例。而CT和 (或 )MRI仅 5 6 5 2 % (2 6例 )异常 ,EEG 82 60 % (3 8例 )异常。 9例示局限性高代谢区患者 1周后在确认检查前后 12h均未发作的前提下再次行PET检查 ,结果发现其中 7例同一部位出现低代谢区 ,另 2例代谢也有所降低。结论　18F FDGPET对发作间期癫痫灶的诊断价值明显优于CT和 (或 )MRI和头皮EEG ,尤其在发作间期和发作期各检查 1次 ,或延长发作后检查时间 ,可提高灵敏度和特异性及诊断准确性。     

发作间期SPECT对难治性颞叶癫痫的诊断价值

目的:探讨难治性颞叶癫痫(TLE)单光子发射计算机断层(SPECT)的影像特征及定位诊断价值.方法:选择35例经临床手术证实的难治性TLE,术前均行发作间期SPECT脑血流灌注显像和常规MRI扫描.以临床定位结果做对照,观察难治性TLE的SPECT影像改变,分析发作间期脑血流灌注显像定位诊断颞叶致痫灶的临床应用价值.结果:难治性颞叶癫痫SPECT的影像特征为致痫灶侧前颞叶内侧和/或外侧皮质的血流灌注减低,对侧前颞叶的内侧皮质可出现轻度的灌注减低.常合并与患侧同侧的一处或以上脑区的灌注减低.SPECT致痫灶定位诊断的阳性率达77.14％00(27/35),尤其能检出52.94％ (9/17) MRI阴性TLE的致痫灶.结论:发作间期SPECT脑血流灌注显像能丰富难治性TLE的定位诊断信息,提高定位MRI阴性TLE患者致痫灶的比例.     

SPECT、EEG、MRI综合评价难治性癫痫灶定位的价值

目的:探讨SPECT、EEG和MRI综合评价难治性癲痫灶定位的临床价值.材料和方法:对41例拟手术的癫痫患者行发作期和发作间期脑血流灌注显像,其结果与EEG、MRI、病理结果及临床表现进行比较,并综合各项检查结果确定致痫灶.结果:41例患者均行手术,有29例患者SPECT、EEG和MRI病灶定位一致,术后发作次数明显减少或痊愈;12例患者三种检查病灶定位不完全一致,11例术后发作次数减少,1例无效.结论:三种检查手段综合评价对定位致痫灶有较高的临床应用价值.对手术前制定手术方案有较高的指导作用.     

癫痫发作期与发作间期脑血流灌注显像减影法定位致痫灶的价值

目的:研究癫痫发作期与发作间期脑血流灌注显像减影法定位致癫灶的价值.材料和方法:14例癫痫患者在癫痫发作期和发作间期分别进行脑血流灌注显像,两次所得图像进行空间匹配后相减得到减影像,并与EEG、MRI、手术结果及临床表现比较.结果:与发作间期相比,13/14例发作期局部脑血流有不同程度的增高,减影像可显示血流改变的具体部位及形态;1例发作期血流低于发作间期,但病灶区表现明显.手术后病灶病理诊断包括胶质细胞增生、疤痕组织及胶质细胞瘤.术后13例患者发作次数明显减少,1例效果不显著.结论:发作期与发作间期显像减影法定位致痫灶有较高的准确性,有助于术前制定合理的手术方案.     

18F-FDGPET/CT脑显像在癫发作期及发作间期致灶定位中的应用价值

 目的探讨¹⁸F-FDGPET/CT脑3D显像在癫发作期和发作间期致灶定位中的应用价值。方法癫患者60例均行24h头皮脑电图、MRI、¹⁸F-FDGPET/CT脑显像。25例行皮质脑电图(ECoG)或深部脑电图(DEEG)。PET/CT图像经过目测和半定量的方法进行分析。结果(1)60例中,¹⁸F-FDGPET/CT脑显像阳性者57例,检出率95%,其中患者处于发作间期56例,PET/CT表现为低代谢灶者53例,发作期4例,PET/CT上均表现为高代谢灶。(2)PET/CT显示80%为单发灶(48/60),15%为2个以上病灶(9/60)。单发灶中,66.7%位于颞叶(32/48),另33.3%位于颞叶外皮质(顶叶6例,额叶10例)。(3)PET/CT与皮质脑电图(ECoG)或深部脑电图(DEEG)符合率为96%(24/25)。(4)32例颞叶癫行前颞叶切除术,术后随访结果EngelⅠ～Ⅱ级者30例。非颞叶癫16例,行致灶皮质切除术,12例达EngelⅠ～Ⅱ级。3例未检出致灶,9例DEEG定位双侧致灶未行手术治疗。结论对于颅内有病灶癫及明确的颞叶癫患者,PET/CT与EEG以及MRI检查结果具有高度一致性;对于没有病灶及非颞叶癫患者,PET/CT是一种无创、敏感、有效的定位癫源灶的方法。     

Comparative analysis of MR imaging,Ictal SPECT and EEG in temporal lobe epilepsy: a prospective IAEA multi-center study

Background and purpose MR imaging, ictal single-photon emission CT (SPECT) and ictal EEG play important roles in the presurgical localization of epileptic foci. This multi-center study was established to investigate whether the complementary role of perfusion SPECT, MRI and EEG for presurgical localization of temporal lobe epilepsy could be confirmed in a prospective setting involving centers from India, Thailand, Italy and Argentina. Methods We studied 74 patients who underwent interictal and ictal EEG, interictal and ictal SPECT and MRI before surgery of the temporal lobe. In all but three patients, histology was reported. The clinical outcome was assessed using Engel’s classification. Sensitivity values of all imaging modalities were calculated, and the add-on value of SPECT was assessed. Results Outcome (Engel’s classification) in 74 patients was class I, 89%; class II, 7%; class III, 3%; and IV, 1%. Regarding the localization of seizure origin, sensitivity was 84% for ictal SPECT, 70% for ictal EEG, 86% for MRI, 55% for interictal SPECT and 40% for interictal EEG. Add-on value of ictal SPECT was shown by its ability to correctly localize 17/22 (77%) of the seizure foci missed by ictal EEG and 8/10 (80%) of the seizure foci not detected by MRI. Conclusions This prospective multi-center trial, involving centers from different parts of the world, confirms that ictal perfusion SPECT is an effective diagnostic modality for correctly identifying seizure origin in temporal lobe epilepsy, providing complementary information to ictal EEG and MRI. Part of this work was presented at the 2005 SNM meeting in Toronto, Canada.     

Limited value of interictal brain perfusion SPECT for detection of epileptic foci: High resolution SPECT studies in comparison with FDG-PET

Accurate localization of epileptic foci is important for pre-surgical evaluation of patients with medically intractable epilepsy, and F-18 FDG PET has been proved to be a valuable method for this purpose. To examine the clinical value with interictal brain perfusion SPECT, we performed brain perfusion SPECT of Tc-99m HMPAO by means of a high resolution SPECT camera, and compared the results with F-18 FDG PET images and MRI in 10 patients with medically intractable epilepsy. In 9 of 10 patients (90%), FDG PET images showed focal hypo-metabolism in the area corresponding with the results of electroencephalography (EEG). SPECT images, however, demonstrated hypo-perfused lesions which corresponded with hypo-metabolic lesions on FDG PET images in only 6 cases (60%). Although MRI showed abnormal findings in 8 cases, the lesions were not directly related to epileptic foci in 2 cases. In conclusion, FDG PET is a valuable tool for accurate localization of epileptic foci. Brain perfusion SPECT, however, may not always be paralleled to metabolism visualized on FDG PET images.     

Comparative analysis of MR imaging, positron emission tomography, and ictal single-photon emission CT in patients with neocortical epilepsy

BACKGROUND AND PURPOSE: MR imaging, positron emission tomography (PET), and single-photon emission CT (SPECT) play important roles in presurgical localization of epileptic foci. However, comparative study of these imaging methods for cases of neocortical epilepsy has been limited. The purpose of this study was to compare the sensitivities of these three imaging methods for presurgical localization of neocortical epileptogenic foci. METHODS: We studied 117 consecutive patients who underwent surgery for intractable neocortical epilepsy. The pathologic substrates were neuronal migration disorder (n = 77), tumor (n = 15), and others (n = 25). MR imaging was compared retrospectively with (18)F-fluorodeoxyglucose PET and ictal technetium-99m hexamethylpropyleneamine oxime SPECT regarding their capability to correctly localize the epileptogenic foci. The pathologic findings were used as the standard of reference. RESULTS: Overall, MR imaging, PET, and ictal SPECT correctly localized the lesions for 59.8%, 77.7%, and 70.3% of the patients, respectively, with a 38% concordance rate among the three methods. PET was most sensitive (71-100%) in detecting all substrates. MR imaging was as sensitive (100%) as PET in detecting tumor but was least sensitive (48.1%) in detecting neuronal migration disorder. Ictal SPECT was more sensitive (75.8%) than MR imaging in detecting neuronal migration disorder. Patients with imaging abnormalities achieved good outcomes in 81.4% of the cases, in contrast to 59.5% for those without imaging abnormalities (P <.05). CONCLUSION: PET and ictal SPECT were overall more sensitive than was MR imaging, despite the low concordance rate and variable sensitivity depending on substrates. The detection of abnormalities by MR imaging was associated with good outcome. PET or ictal SPECT can be well used as complementary tools, particularly in cases of negative MR imaging findings.     

The value of interictal brain SPECT in epilepsy patients without mesial-temporal sclerosis

PURPOSE: Most of the literature concerning interictal SPECT brain scanning in patients with seizures has involved the evaluation of those with temporal lobe epilepsy. The authors' aim was to determine the utility of interictal SPECT in patients with neocortical epilepsy. MATERIALS AND METHODS: Eighty-four patients with neocortical epilepsy were evaluated with 95 interictal SPECT scans and magnetic resonance imaging (MRI). RESULTS: Fifty-four percent of studies with normal MRI findings had SPECT images without regions of hypoperfusion. Sixty-one percent of patients with abnormal MRI results had matching defects visible on SPECT images. Fourteen scans (only 24%) had focal hypoperfusion by SPECT and no obvious matching MRI finding. CONCLUSIONS: Interictal SPECT, without a comparison ictal study, is of potentially limited value in localizing neocortical seizure foci. SPECT findings usually match MRI findings. Interictal SPECT, however, may still be of value in confirming abnormalities detected by ictal examination.     

Comparison of MR imaging with PET and ictal SPECT in 118 patients with intractable epilepsy.

BACKGROUND AND PURPOSE: MR imaging, PET, and ictal SPECT have been studied extensively as individual techniques in the localization of epileptogenic foci, but only a few comparative studies have been done. We evaluated the concordance rates of ictal video/EEG, MR imaging, PET, and ictal SPECT to compare the sensitivities of these imaging methods in the lateralization of epileptogenic foci. METHODS: The study included 118 consecutive patients who underwent surgery for medically intractable epilepsy and who were followed up for 12 months or more. MR imaging was compared retrospectively with ictal video/EEG, FDG-PET, ictal 99mTc-HMPAO SPECT, and invasive EEG as to their ability to localize the epileptogenic focus; the pathologic findings served as the standard of reference. RESULTS: MR imaging was concordant with video/EEG, PET, and ictal SPECT in 58%, 68%, and 58% of patients, respectively. With the pathologic diagnosis as the standard of reference, MR imaging, PET, and ictal SPECT correctly lateralized the lesion in 72%, 85%, and 73% of patients, respectively. Of the patients with good outcomes, MR imaging, PET, and ictal SPECT were correct in 77%, 86%, and 78%, respectively. In the good outcome group, MR imaging was concordant with PET and ictal SPECT in 73% and 62% of patients, respectively. Of 45 patients who underwent invasive EEG, MR imaging was concordant with the invasive study in 47%; PET in 58%; and ictal SPECT in 56%. Of 26 patients with normal MR findings, PET and ictal SPECT correctly lateralized the lesion in 80% and 55%, respectively. CONCLUSION: Overall concordance among the techniques is approximately two thirds or less in lateralizing epileptogenic foci. PET is the most sensitive, even though it provides a broad approximate nature of the epileptogenic zone, which is not adequate for precise surgical localization of epilepsy. PET and/or ictal SPECT may be used as complementary tools in cases of inconclusive lateralization with ictal video/EEG and MR imaging.