^123I—IomazenilSPECT脑受体显像对癫痫灶定位的价值

目的探讨１２３ＩＩｏｍａｚｅｎｉｌＳＰＥＣＴ脑受体显像对癫痫灶定位诊断的价值。方法对４０例癫痫病人进行１２３ＩＩｏｍａｚｅｎｉｌＳＰＥＣＴ脑受体显像，并与录像脑电图强化监测（Ｖｉｄｅｏ／ＥＥＧ）、９９ｍＴｃ六甲基丙二胺肟（ＨＭＰＡＯ）ＳＰＥＣＴ脑血流显像和ＭＲＩ检查结果进行对比分析。结果以Ｖｉｄｅｏ／ＥＥＧ癫痫灶检出率９５％（３８／４０）为参照标准，６５８％（２５／３８）癫痫病人脑受体显像异常，表现为局部放射性稀疏，与Ｖｉｄｅｏ／ＥＥＧ定位符合２０例；脑血流显像和ＭＲＩ癫痫灶检出率分别为５５３％（２１／３８）和４７４％（１８／３８），与Ｖｉｄｅｏ／ＥＥＧ定位符合分别为１５例和１６例。１２３ＩＩｏｍａｚｅｎｉｌ脑受体显像联合ＭＲＩ检查，癫痫灶检出率为８４２％（３２／３８）。４例ＭＲＩ、脑血流和受体显像正常患者１８Ｆ脱氧葡萄糖（ＦＤＧ）ＰＥＴ显像全部异常，并均与Ｖｉｄｅｏ／ＥＥＧ定位符合。结论１２３ＩＩｏｍａｚｅｎｉｌＳＰＥＣＴ脑受体显像是癫痫病灶定位的有效方法，与ＭＲＩ配合，能提高病灶检出率。     

脑SPECT显像在癫痫中的应用

目的：本文主要研究脑ＳＰＥＣＴ在癫痫应用中的作用和地位。材料和方法：对８１例癫痫患者进行了１０２次发作间期脑ＳＰＥＣＴ血流灌注显像，并与ＥＥＧ、脑ＣＴ、ＭＲＩ比较。结果：８１例ＳＰＥＣＴ检查中６６例显示异常，检出率８１．４％（６６／８１），ＥＥＧ、ＭＲＩ、ＣＴ阳性率分别为８２．９８％（３９／４７）、３８．２４％（１３／３４）、４５．９５％（１７／３７）。结论：ＳＰＥＣＴ显像在癫痫诊断和定位方面与ＥＥＧ、ＭＲＩ、ＣＴ相比具有优势，且有助于癫痫病灶局部血流变化与临床症状、疗效及其他影响因素之间关系的研究。     

SPECT脑血流显像定位诊断癫痫病灶的临床应用──与CT、皮质脑电图及病理检查对比分析

对１４２例癫痫病人进行间歇期ＳＰＥＣＴ局部脑血流显像，并与脑ＣＴ、ＭＲＩ、ＥＥＧ、皮质脑电图（ＥＣｏＧ）及手术病理结果进行比较。结果表明，ＳＰＥＣＴ阳性率最高（７５．４％），ＣＴ和ＭＲＩ分别为５２．０％和５６．７％．ＳＰＥＣＴ能准确定位癫痫灶，与埋藏式ＥＣｏＧ或术中ＥＣｏＧ标测结果（ｎ＝５１）的符合率达９２．０％。致痫灶的病理改变多为隐匿性脑血管畸形、胶质增生、局灶性神经元固缩、变性及排列紊乱等。研究表明ＳＰＥＣＴ局部脑血流显像是诊断癫痫病灶的有效方法，灵敏度优于ＣＴ和ＭＲＩ，定位价值优于ＥＥＧ，对于制订癫痫的手术治疗方案有一定帮助。     

SPECT脑血流显像定位诊断癫痫病灶的临床应用—与CT,皮质脑电图…

对１４２例癫痫病人进行间歇期ＳＰＥＣＴ局部脑血流显像，并与脑ＣＴ、ＭＲＩ、ＥＥＧ、皮质脑电图及手术病理结果进行比较。研究表明ＳＰＥＣＴ局部脑血液显像是诊断癫痫病灶的有效方法，灵敏度优于ＣＴ和ＭＲＩ，定位价值优于ＥＥＧ，对于制订癫痫的手术治疗方案有一定帮助。     

癫痫发作期和发作间期~（99m）Tc－ECD脑断层显像

癫痫发作期和发作间期~（９９ｍ）Ｔｃ－ＥＣＤ脑断层显像［英］／ＧｒｕｎｗａｌｄＦ…∥ＪＮｕｃＩＭｅｄ．－１９９４，３５（１２）．－１８９６～１９０１方法：１６例患者行２３次脑ＳＰＥＣＴ（ＣＥＲＡＳＰＥＣＴ）显像研究，其中８次为发作期显像，１５次为发作?..     

SPECT和PET对脑肿瘤的诊断

ＣＴ和ＭＲＩ已成为现代脑肿瘤检查的重要形态学检查内容,ＳＰＥＣＴ和ＰＥＴ利用不同的药物对肿瘤内部的生化及代谢活动进行显像,从而可得到ＣＴ,ＭＲＩ解剖结构显像以外的代谢等功能性信息,用于ＳＰＥＣＴ脑肿瘤显像的药物有＾２０１Ｔｌ和＾９９ｍＴｃ标记的ＭＩＢＩ、ＤＭＳＡ（Ｖ）、Ｔｅｔｒｏｆｏｓｍｉｎ,＾１２３Ｉ标记的ＩＭＴ,＾１１Ｉｎ标记的生长抑素受体类药物（Ｏｃｔｒｅｏｔｉｄｅ）等。针对肿瘤的葡萄糖代谢     

发作间期SPECT脑灌注显像在癫痫手术定位中的价值

本研究分析了８６例癫痫患者ＳＰＥＣＴ局部脑血流（ｒＣＢＦ）显像、ＥＥＧ和ＣＴ或ＭＲＩ与术中皮层脑电图（ＥＣｏＧ）的关系,以探讨ＳＰＥＣＴ脑血流灌注显像对癫痫灶定位的作用。资料与方法１临床资料。受检者共８６例,男５７例,女２９例,年龄２５～４９岁;...     

儿童良性部分性癫痫SPECT显像特点

目的探讨儿童良性部分性癫痫（ＢＰＥ）的ＳＰＥＣＴ显像特点。方法２１例ＢＰＥ患儿，在ＥＥＧ监测下，分别在觉醒期（棘波发放间期）和睡眠期（棘波发放期）进行ＳＰＥＣＴ显像，减影处理后重建断层影像。用脑血流功能变化率（ＢＦＣＲ％）数学模型进行定量分析。结果ＥＥＧ监测显示患儿觉醒期背景活动基本正常，睡眠期棘波发放频率明显增多。ＳＰＥＣＴ共见１１７个痫灶，平均每例５６±１６个。ＳＰＥＣＴ显像特点为：①多灶性镜像分布；②主要位于Ｒｏｌａｎｄｉｃ区；③“环形征”；④觉醒期的多处放射性减低区，睡眠期放射性明显填充。ＳＰＥＣＴ与ＥＥＧ的符合率为９３１％（１０９／１１７）。痫灶的ＢＦＣＲ％皆高于对应正常局部脑自然变化的范围（９９％可信区间）。棘波发放频率和ＢＦＣＲ％之间无相关性（ｒ＝０４５，Ｐ＞００５）。结论ＢＰＥ痫灶异常放电时，可致局部脑血流灌注和功能异常     

Gd—DTPAMRI在心绞痛中的作用

目的：探讨Ｇｄ－ＤＴＰＡ增强ＭＲＩ在心绞痛中的作用。材料和方法：２２例心绞痛作Ｇｄ－ＤＴＰＡ增强前后ＭＲＩ检查,其中１６例作冠状动脉造影检查,１１例作ＳＰＥＣＴ检查。结果：增强ＭＲＩ上,１８例（８２％）可见局部异常强化信号,其部位与临床ＥＣＧ吻合,与ＣＡ、ＳＰＥＣＴ所示心肌缺血部位一致。在ＭＲＩ上的异常强化信号与冠状动脉狭窄、ＳＰＥＣＴ显示灌注缺损密切有关。结论：Ｇｄ－ＤＴＰＡＭＲＩ为心绞痛的诊断提供有价值的依据。     

~(99)Tc~m-ECD SPECT显像观察脑血流量随年龄的变化

用Ｐａｔｌａｋ Ｐｌｏｔ法及99Ｔｃｍ 双半胱乙酯(ＥＣＤ)对 65例脑ＣＴ、ＭＲＩ检查无异常者进行脑血流断层显像 ,观察平均脑血流量 (ｍＣＢＦ)和局部脑血流量 (ｒＣＢＦ)随年龄增长的变化特点。一、资料和方法1 临床资料。对 65例ＣＴ、ＭＲＩ检查无异常发现者进行了99Ｔｃｍ ＥＣＤＳＰＥＣＴ脑血流断层显像。男 3 4例 ,女 3 1例 ,年龄 1～ 79(平均 3 0 5 )岁。均经临床检查除外精神、神经系统疾病。2 方法。ＥＣＤ由江苏省原子医学研究所提供 ,99Ｔｃｍ 由中国原子能科学研究院提供。显像仪器为ＧＥＳｔａｒｃａｍ 3 2 0 0ｉＳＰＥＣ…     

Correlation of MRI hippocampal volume analysis,video/EEG monitoring and inter- and postictal single photon emission tomography in refractory focal epilepsy

The effectiveness of surgery in patients with refractory complex partial seizures depends on accurate localisation of the epileptogenic zone. To assess the correlation between magnetic resonance imaging (MRI) hippocampal volume measurements, Tc 99m-hexamethyl-propyleneamineoxime inter- and postictal single photon emission computed tomography (SPECT) and clinico-electrophysiological (video/EEG) localisation of the epileptogenic zone we prospectively studied 16 consecutive patients with refractory complex partial seizures and no significant abnormality on standard MRI. Each test was interpreted blindly by independent observers. Eight patients (50%) had asymmetrical hippocampal volumes indicative of unilateral atrophy; correlation with the video/EEG and postical SPECT changes was very high (100% with definitive video/EEG localisation, 75% with interictal EEG and 83% with postictal SPECT). Moreover, the left/right hippocampal ratio was able to differentiate temporal from extratemporal video/EEG localisations. Postictal SPECT showed regional lateralised changes in 9 (64%) of 14 technically satisfactory studies. Disagreement between the video/EEG and postictal SPECT was seen with two extratemporal and one bitemporal foci.     

Ictal SPECT in neocortical epilepsies: clinical usefulness and factors affecting the pattern of hyperperfusion

Introduction: The aims of this analysis were to: (1) determine the value of ictal SPECT in the localization of neocortical epileptogenic foci, (2) evaluate the relationships between the results of ictal SPECT and other potential affecting factors, and (3) compare traditional visual analysis and the subtraction method.Methods: We retrospectively analyzed 81 consecutive patients with neocortical epilepsy who underwent epilepsy surgery and achieved a favourable surgical outcome, including 36 patients with normal MRI. Side-by-side visual analysis and subtraction images were classified as correctly localizing,correctly lateralizing, or non-localizing/non-lateralizing images according to the resected lobe.Results: Side-by-side visual analysis and subtraction SPECT correctly localized the epileptogenic lobe in 58.9% and 63.0% of patients, respectively. The two methods were complementary and the diagnostic sensitivity of ictal SPECT using the two methods was 79.0%. Ictal SPECT using the visual method correctly localized the epileptogenic lobe more frequently in patients with a localizing pattern of ictal scalp EEG at the time of radioligand injection. When using subtraction images, an injection delay of less than 20 s after seizure onset was significantly correlated with correct localization. The subtraction method was superior to the visual method for localizing frontal lobe epilepsy (FLE) and parietal lobe epilepsy (PLE), and in patients with non-localizing/non-lateralizing EEG at onset.Conclusions: Ictal SPECT analyses using visual and subtraction methods are useful and complementary for the localization of the epileptogenic foci of neocortical epilepsy. Early radioligand injection and ictal EEG patterns are related to ictal SPECT localization. The subtraction method may be more useful in some epileptic syndromes.     

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.     

Sensitivity and specificity of quantitative difference SPECT analysis in seizure localization.

True ictal SPECT can accurately demonstrate perfusion increases in the epileptogenic area but often requires dedicated personnel waiting at the bedside to accomplish the injection. We investigated the value of perfusion changes as measured by ictal or immediate postictal SPECT in localizing the epileptogenic region in refractory partial epilepsy. METHODS: Quantitative perfusion difference images were calculated by registering, normalizing and subtracting ictal (or immediate postictal) from interictal SPECT for 53 patients with refractory epilepsy. Perfusion difference SPECT results were compared with visually interpreted SPECT, scalp electroencephalography (EEG), MRI, PET and intracranial EEG. RESULTS: In 43 patients (81%), discrete areas of increased perfusion (with ictal injections) or decreased perfusion (with postictal injections) were noted. Interictal scalp EEG was localizing in 28 patients (53%), ictal scalp EEG was localizing in 35 patients (66%) and intracranial EEG was localizing in 22 patients (85%) (of 26 patients who underwent invasive study). MRI was localizing in 34 patients (64%), PET was localizing in 32 of 45 patients (71%), interictal SPECT was localizing in 26 patients (49%) and peri-ictal SPECT (visual interpretation) was localizing in 30 patients (57%). By comparison with an intracranial EEG standard of localization, SPECT subtraction analysis had 86% sensitivity and 75% specificity. CONCLUSION: Our data provide evidence that SPECT perfusion difference analysis has higher sensitivity and specificity than any other noninvasive localizing criterion and can localize epileptogenic regions with accuracy comparable with that of intracranial EEG. To obtain these results, one must apply knowledge of the timing of the ictal injection relative to seizure occurrence.     

Evaluation of focal epilepsy: a SPECT scanning comparison of 123-I-iomazenil versus HM-PAO.

PURPOSE: To establish whether regional disturbances of the benzodiazepine receptor distribution in focal epilepsies can be detected by SPECT using 123-I-Iomazenil. PATIENTS AND METHODS: Benzodiazepine receptor imaging was carried out in 10 patients interictally. To be eligible for this study the patients had to have a history of focal seizures and no evidence of routine imaging abnormalities as in CT or MR. The patients were selected on the basis of a regional decreased blood flow in HMPAO SPECT that correlated with the site of a stable unifocal EEG abnormality. Benzodiazepine receptor imaging was performed after intravenous administration of approximately 110 MBq 123-I-Iomazenil using SPECT. RESULTS: A regional reduced activity was found on sequential SPECT series after 30 and 90 min post injection in the receptor study. The brain region with a reduced receptor density was concordant to the pathologic finding in HMPAO SPECT in all patients. CONCLUSION: For the evaluation of patients with focal epilepsies lomazenil SPECT offers several advantages over HMPAO SPECT. Iomazenil binds specifically to the benzodiazepine receptor complex whereas the exact binding sites of HMPAO are still unknown. In contrast to HMPAO, lomazenil can be used for sequential SPECT examinations that may detect dynamic changes of the receptor complex. For the purpose of benzodiazepine receptor imaging, lomazenil is a suitable ligand in patients with focal epilepsies.     

Presurgical evaluation of refractory temporal lobe epilepsy: Comparison of MR imaging,PET and ictal SPECT in localization of the epileptogenic substrate

Purpose

To compare the sensitivities of MRI, FDG-PET and ictal/SPECT in localization of the epileptogenic substrate in patients with refractory temporal lobe epilepsy.

Patients and methods

This study included 137 patients who received surgical treatment for intractable epilepsy. MRI, FDGPET and ictal ^99mTc-HMPAO SPECT were retrospectively reviewed regarding their sensitivity in lateralization of the epileptogenic zone compared to video/EEG, pathological results and surgical outcome.

Results

104 MR-positive and 33 MR-negative patients were enrolled. In the MR-positive group, MRI, PET and ictal/SPECT were concordant to video/EEG in 72%, 83% and 73%, respectively. When compared to pathological diagnosis, they correctly lateralized the epileptogenic zone in 70%, 87%, and 73%, respectively. In patients with good surgical outcome, they correctly localized the epileptogenic zone in 79%, 88%, and 78%, respectively. In the MR-negative group, PET and ictal/SPECT were concordant with video/EEG in 82% and 58%, respectively and matching with pathological diagnosis in 85% and 56%, respectively.

Conclusion

PET is the most sensitive method in lateralization of the epileptogenic substrate. The use of MRI, PET and ictal/SPECT as a multimodality approach improves lateralization of the affected zone particularly in cases with negative MR findings and distinguishes patients who will benefit from surgery.     

MRI-based correction for partial-volume effect improves detectability of intractable epileptogenic foci on 123I-iomazenil brain SPECT images.

(123)I-Iomazenil brain SPECT has been used for the detection of epileptogenic foci, especially when surgical intervention is considered. Although epileptogenic foci exhibit a decrease in (123)I-iomazenil accumulation, normal cerebral cortices often exhibit similar findings because of thin cortical ribbons, gray matter atrophy, or pathologic brain structures. In the present study, we created (123)I-iomazenil SPECT images corrected for gray matter volume using MRI and tested whether the detectability of the epileptogenic foci improved. METHODS: Seven patients (1 male patient and 6 female patients; mean age +/- SD, 34 +/- 17 y) with intractable epilepsy were surgically treated by resecting the cerebral cortex after surface electroencephalography. Histopathologic examination of the resected specimens and a good outcome after surgery indicated that the resected lesions were epileptogenic foci. These patients underwent (123)I-iomazenil SPECT and 3-dimensional T1-weighted MRI examinations before their operations. Each SPECT image was coregistered to the corresponding MR image, and its partial-volume effect (PVE) was corrected on a voxel-by-voxel basis with a smoothed gray matter distribution image. Four nuclear medicine physicians visually evaluated the (123)I-iomazenil SPECT images with and without the PVE correction. The SPECT count ratio of the suspected focus to the contralateral cerebral cortex was evaluated as an asymmetry index (%) based on the volume of interest. RESULTS: The sensitivity, specificity, and accuracy of focus detection by visual assessment were higher after PVE correction (88%, 99%, and 98%, respectively) than before correction (50%, 92%, and 87%, respectively). The mean asymmetry index for the surgically resected lesions was significantly higher on the PVE-corrected SPECT images (22%) than on the PVE-uncorrected ones (16%) (P = 0.006). CONCLUSION: MRI-based PVE correction for (123)I-iomazenil brain SPECT improves the sensitivity and specificity of the detection of cortical epileptogenic foci in patients with intractable epilepsy.     

SPECT imaging of GABAA/benzodiazepine receptors and cerebral perfusion in mild cognitive impairment

Purpose

The involvement of neocortical and limbic GABA_A/benzodiazepine (BZD) receptors in Alzheimer’s disease (AD) is controversial and mainly reported in advanced stages. The status of these receptors in the very early stages of AD is unclear and has not been explored in vivo. Our aims were to investigate in vivo the integrity of cerebral cortical GABA_A/BZD receptors in subjects with amnestic mild cognitive impairment (MCI) and to compare possible receptor changes to those in cerebral perfusion.

Methods

[¹²³I]Iomazenil and [^99mTc]HMPAO SPECT images were acquired in 16 patients with amnestic MCI and in 14 normal elderly control subjects (only [¹²³I]iomazenil imaging in 5, only [^99mTc]HMPAO imaging in 4, and both [¹²³I]iomazenil and [^99mTc]HMPAO imaging in 5). Region of interest (ROI) analysis and voxel-based analysis were performed with cerebellar normalization.

Results

Neither ROI analysis nor voxel-based analysis showed significant [¹²³I]iomazenil binding changes in MCI patients compared to control subjects, either as a whole group or when considering only those patients with MCI that converted to AD within 2 years of clinical follow-up. In contrast, the ROI analysis revealed significant hypoperfusion of the precuneus and posterior cingulate cortex in the whole group of MCI patients and in MCI converters as compared to control subjects. Voxel-based analysis showed similar results.

Conclusion

These results indicate that in the very early stages of AD, neocortical and limbic neurons/synapses expressing GABA_A/BZD receptors are essentially preserved. They suggest that in MCI patients functional changes precede neuronal/synaptic loss in neocortical posterior regions and that [^99mTc]HMPAO rCBF imaging is more sensitive than [¹²³I]iomazenil GABA_A/BZD receptor imaging in detecting prodromal AD.     

The usefulness of repeated ictal SPET for the localization of epileptogenic zones in intractable epilepsy

This study investigated whether repeated ictal single-photon emission tomography (SPET) is helpful in the localization of epileptogenic zones and whether it can provide information confirming that an area of increased perfusion is really the culprit epileptogenic lesion. Fifty-four repeated ictal SPET studies were performed in 24 patients with ambiguous or unexpected findings on the first ictal SPET study. These patients were enrolled from among 502 patients with intractable epilepsy in whom pre-operative localization of epileptogenic zones was attempted with a view to possible surgical resection. Video monitoring of ictal behaviour and EEGs was performed in all patients. Repeated ictal SPET was performed using technetium-99m hexamethylpropylene amine oxime (HMPAO) when there was no prominently hyperperfused area or when unexpected findings were obtained during the first study. Two ictal SPET studies were performed in 19 patients, three studies in four patients and four studies in one patient. The average delay between ictal onset and injection was 28 s for the first study and 22 s for the second, third and fourth studies. Using interictal SPET, ictal-interictal subtraction images were acquired and co-registered with the population magnetic resonance imaging (MRI) template. Invasive study and surgery were performed in 18 patients, and in these cases the surgical outcome was known. In the other six patients, epileptogenic foci were determined using MRI, positron emission tomography (PET) and ictal EEG findings. Two patients were found to have mesial temporal lobe epilepsy, two lateral temporal lobe epilepsy, eight frontal lobe epilepsy, three parietal lobe epilepsy and one occipital lobe epilepsy. The other eight had multifocal epilepsy. The first study was normal in 12 patients (group I) and indicated certain zones to be epileptogenic in the other 12 (group II). Among group I, the correct epileptogenic zone or lateralization was revealed at the repeated study in nine patients, while in the other three it was not. Among group II, six patients showed the same results at the second study, thus confirming that the initially identified zones were of epileptogenic significance. In the other six patients, different areas were identified on the first and second studies, and repeated ictal SPET corroborated multifocality of the ictal EEG findings in five. These results indicate that repeated ictal SPET is useful because it can yield new or additional information about the epileptogenic zones and can confirm that a region of interest is an epileptogenic zone or that the epilepsy is of multifocal origin.     

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.