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.     

脑外伤后综合征的SPECT显像初步观察

脑外伤后综合征发病机理尚不十分清楚，本研究通过４２例临床诊断为脑外伤后综合征患者的脑ＳＰＥＣＴ显像和其他辅助诊断技术及病理资料等，探讨其发病机理。结果发现４２例患者中有３３例ＳＰＥＣＴ显像呈异常表现，占７８．６％。３３例脑ＳＰＥＣＴ显像异常患者中１３例呈多发性放射性减低灶，这提示脑外伤后综合征的发病有其病理、生理基础，而且和脑血流灌注关系密切。并且提示脑外伤后，脑实质的损害还有可能为弥漫性的，并不     

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.     

99 Tcm-ECD SPECT显像定位致

目的探讨99Tcm-双半胱乙酯(ECD) SPECT显像对原发性癫致灶定位的价值.方法经临床和头皮脑电图(EEG)诊断为癫的34例患者行SPECT发作间期及发作期局部脑血流(rCBF)显像,以确定致灶.结果 22例患者发作间期rCBF显像出现rCBF灌注减低,28例发作期显示血流灌注增加,两期吻合的部位确定为致灶,据此行伽玛刀治疗.结论 SPECT对致灶定位有很大价值.     

~(99)Tc~m-ECDSPECT显像定位致灶的价值

目的　探讨99Tcm 双半胱乙酯 (ECD)SPECT显像对原发性癫致灶定位的价值。方法　经临床和头皮脑电图 (EEG)诊断为癫的 3 4例患者行SPECT发作间期及发作期局部脑血流(rCBF)显像 ,以确定致灶。结果　 2 2例患者发作间期rCBF显像出现rCBF灌注减低 ,2 8例发作期显示血流灌注增加 ,两期吻合的部位确定为致灶 ,据此行伽玛刀治疗。结论　SPECT对致灶定位有很大价值。     

脑SPECT显像对高压氧治疗脑外伤后脑缺血疗效判断的价值

目的探讨SPECT脑血流灌注显像对高压氧（HBO）治疗脑外伤继发脑缺血患者疗效判断的价值。方法将65例脑外伤继发脑缺血患者按随机数字表法分为HBO治疗组和常规治疗组,在治疗前后分别进行脑血流灌注SPECT显像,应用计算机感兴趣区（ROI）技术,在横断面图像上采用局部镜像比值（Ra）法判断脑缺血病灶,Ra≤0．9视为异常。对治疗前后的脑血流灌注减低区Ra值进行比较。数据间的比较行t检验。结果HBO治疗组治疗前后局部脑血流（rCBF）减低区Ra值分别为0．58±0．11和0．82±0．12（t=7．327,P〈0．01）,常规治疗组治疗前后rCBF减低区Ra值分别为0．61±0．13和0．73±0．12（t=2．153,P=0．038）;HBO治疗组和常规治疗组缺血灶rCBF增加值分别为0．24±0．08和0．12±0．06（t=2．571,P=0．015）。结论SPECT脑血流灌注显像可灵敏地反映HBO治疗脑外伤后脑缺血前后rCBF变化,可用于HBO治疗疗效的评价。     

橄榄桥脑小脑萎缩SPECT脑显像和MRI对比研究

目的 评价SPECT脑血流灌注显像在橄榄桥脑小脑萎缩（OPCA）诊断中的价值。方法 对20例OPCA患者行SPECT脑血流灌注显像和头颅MRI检查,并对各项检查结果进行比较。结果 OPCA患者的SPECT显像异常表现为脑局部血流低灌注,以脑干、脑小及基底节为主,也可累及大脑各叶;与MRI比较,SPECT显示病变范围更广泛;SPECT和MRI的异常率分别为95％和75％。结论 SPECT脑血流灌注显像为诊断OPCA提供了新方法,灵敏度优于MRI;SPECT与MRI相结合,有助于提高OPCA诊断的准确性。     

评价99Tcm-ECD脑血流灌注显像检测中毒性脑病局部脑血流变化的价值

目的核素脑血流灌注显像观察了中毒性脑病患者的局部脑血流灌注减低的范围和程度,并且分析局部脑血流与计算机体层摄影术及临床症状的关系.方法采用99m锝-双半胱乙酯单光子发射型计算机断层扫描脑灌注显像检测46例中毒性脑病(包括一氧化碳中毒性脑病30例、一氧化碳中毒后迟发性脑病14例和硫化氢中毒性脑病2例)的局部脑血流改变.结果中毒性脑病患者局部脑血流的异常表现全部为脑皮层的血流灌注减低.单侧局限性脑血流灌注减低14例(30%),双侧局限性减低17例(37%),双侧弥漫性减低12例(26%)及阴性3例(7%).局部脑血流异常病变范围和程度与病情轻重关系密切.中毒性脑病与中毒后迟发性脑病2组患者的局部脑血流病变部位和范围的分布有显著区别(χ2=13.94,P＜0.005).观察了8例治疗前后局部脑血流变化提示局部脑血流变化可以较准确反应临床病情变化.18例(39%)同期作了计算机体层摄影术或磁共振成像检查,15例计算机体层摄影术结果阳性,其中只有6例脑皮层双侧或单侧局部密度减低,并且计算机体层摄影术或磁共振改变与临床病情无密切关系.结论 99m锝-双半胱乙酯的局部脑血流对判断中毒性脑病的病变范围、病变程度以及观察疗效有十分重要的价值.     

脑SPECT血流灌注显像对老年人Alzheimer病和多发性梗塞痴呆的诊断研究

目的：本文旨在研究脑SPECT血流灌注显像对老年人阿尔海默氏病和多发性梗塞痴呆的诊断价值。材料和方法：对6例阿尔海默氏病及6例多发性梗塞痴呆患者进行脑SPECT血流灌注显像，使用放射性药物为^99m锝-六甲基丙叉二胺肟(^99mTc—HMPAO),SPECT结果与MRI、CT相比较。结果：阿尔海默氏病表现为大脑皮质血流灌注的广泛减低，以颞，顶叶较为明显．个别病例一侧大脑皮质灌注减低较对侧明显者伴有同侧基底节或对侧小脑的低灌注，可能与“神经机能联系不能”有关。多发性梗塞痴呆患者，呈不规则、局灶性大脑皮质灌注减低；伴有基底节或小脑的低灌注，与阿尔海默氏病的脑SPECT图像有明显区别。结论：脑SPECT血流灌注显像对阿尔海默氏病与多发性梗塞痴呆的诊断与鉴别诊断有重要价值。     

脑SPECT灌注显像在老年人脑血管疾病中的应用

目的：旨在研究脑SPECT血流灌注显像对老年脑血管疾病的诊断价值。材料和方法：对132例脑血管疾病患者进行脑SPECT血流灌注显像，并将SPECT结果与MRI、CT相比较。结果：脑梗塞患者96．1％有阳性发现，有些灌注减低灶较MRI，CT显示的范围大．可能由于包括了梗塞区及周围缺血半影区的缘故。对神经机能联系不能征象进行了观察．短暂性脑缺血发作患者在发作间期有61.9%阳性．病灶与发作期临床症状相符。脑供血不足、脑动脉硬化、脑出血的阳性率分别为64.3%、80%．95.5%。结论：脑SPECT灌注显像为老年人脑血管疾病的诊断提供了客观依据，有重要应用价值。     

Radionuclide brain perfusion studies in suspected brain death

The radionuclide brain perfusion study (RPS) has been suggested as a method of confirming suspected brain death. The hospital records and RPSs of 34 patients referred were reviewed because brain death was suspected. In every case but one the RPS showed absent or drastically reduced cerebral blood flow. No patient survived more than five days, and 25 survived less than 24 hours. These findings are consistent with the results of previous reports of a total of 248 patients; only one of 248 survived and was discharged from the hospital after having had a positive RPS. The RPS is highly accurate in confirming brain death.     

放射性脑损伤和脑肿瘤复发的鉴别诊断

放射性脑损伤是放射治疗的严重的并发症,其与脑肿瘤复发的鉴别诊断非常困难,目前主要依靠影像学诊断,核磁共振弥散加权像、磁共振波谱、正电子发射型计算机体层显像、单光子发射计算机体层显像等被认为对于鉴别诊断有一定的帮助,但其敏感性和特异性还有待于进一步研究。最终确诊依赖标本的组织学检查。     

弥漫性脑损伤后脑缺血的实验研究

目的　运用大鼠弥漫性脑损伤 (DBI)模型研究脑外伤后脑缺血缺氧的形态学改变。　方法　采用Marmarou的DBI模型 ,光镜下观察微血管改变并测量顶叶皮质内微血管的截面积及微血管周的水肿面积 ;电镜下观察血脑屏障结构的形态学改变并半定量测定毛细血管周围的水肿范围。　结果　光镜下可见外伤后 2 ,6 ,2 4h微血管管径变窄 ,平均微血管截面积分别为 (41.77± 2 7.37) μm2 、(45 .0 9± 2 4 .75 ) μm2 、(49.38± 2 5 .13) μm2 ,均小于对照组 [(6 2 .0 7± 2 8.4 5 ) μm2 ](P <0 .0 5 )。伤后 6 ,2 4h微血管周围存在明显水肿。电镜下 2 ,6 ,2 4h血脑屏障结构有明显损害 ;微血管有痉挛、受压变窄及淤血三种改变。　结论　弥漫性脑损伤后存在明显的脑缺血缺氧的病理形态学改变。     

99mTc HM-PAO brain perfusion SPECT in brain death

Diagnosis of brain death must be certain to allow discontinuation of artificial ventilation and organ transplantation. Brain death is present when all functions of the brain stem have irreversibly ceased. Clinical and electrophysiological criteria may be misinterpreted due to drug intoxication, hypothermia or technical artefacts. Thus, if clinical assessment is suboptimal, reliable early confirmatory tests may be required for demonstrating absence of intracranial blood flow. We have easily carried out and interpreted^99mTc HM-PAO SPECT in a consecutive series of 40 comatose patients with brain damage, without discontinuing therapy. Brain death was diagnosed in 7 patients, by recognising absence of brain perfusion, as shown by no intracranial radionuclide uptake. In patients in whom perfusion was seen on brain scans, HM-PAO SPECT improved assessment of the extent of injury, which in general was larger than suggested by CT.     

大鼠二次脑损伤模型的建立

目的　建立弥漫性脑损伤 (diffusebrianinjury ,DBI)合并缺血性二次脑损伤 (secondarybrianinsult ,SBI)大鼠模型。　方法　在Marmarou模型基础上结扎双侧颈总动脉 30min ,制成缺血性SBI模型 ,观察大鼠神经损伤严重程度评分 (NSS)、脑组织含水量及室上区皮层损伤神经元数改变。　结果　合并SBI组大鼠死亡率 ( 4 8.1 % )约为单纯DBI组 ( 2 6 .2 % )的 2倍 (P <0 .0 5) ;合并SBI组在损伤 2 4h后NSS明显高于单纯DBI组 (P <0 .0 5) ;单纯DBI 1h后脑含水量明显升高 ,于 2 4h达高峰 ,随后逐渐下降 ,1 6 8h降至正常 ,而合并SBI后除 1h组外 ,其余时间组脑含水量均明显高于同时间单纯DBI组 (P <0 .0 5) ,且峰值提前至 1 2h ,1 6 8h仍未恢复正常 ;单纯DBI 6h后皮层神经元明显损伤 (P <0 .0 5) ,1 2h达高峰 ,1 6 8h恢复正常 ,而合并SBI组神经元损伤数 1 2h后还增加 ,2 4h达高峰 ,1 6 8h仍未恢复正常 (P <0 .0 5)。　结论　此模型可以复制SBI的重要临床特征 ,对SBI的基础研究有重要价值。     

Extra-axial brain tumors

Meningiomas, schwannomas, metastases, maldevelopmental cysts, epidermoids, dermoids and bone tumors represent the vast majority of extra-axial brain tumors. The location of extra-axial brain tumors affects treatment planning and predicts their prognosis. Computed tomography and particularly magnetic resonance imaging are used for diagnosis and localization. In this article, the imaging findings of the extra-axial brain tumors are discussed.

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This revised version was published online in March 2005 with corrections to the author's name.     

脑组织氧监测技术在颅脑外伤中的应用

对颅脑损伤所致的缺血、缺氧不良影响已日益受到重视。无论足原发性颅腑损伤,还足继发性颅脑损伤,脑的缺血、缺氧均是影响预后的一个决定件和共同性因素。脑氧监洲技术作为神经科学领域中的新兴技术,与传统的监洲方法相比,有着明显的优越性。其意义不仅在于能早期发现脑缺血、缺氧,准确判断预后,还能及时根据病情变化,指导调整治疗方案,最大限度地改善预后。     

Intra-axial brain tumours

The radiological diagnosis and differential diagnosis of intra-axial tumours no longer relies on CT scan and routine MR sequences alone. Standard multiplanar imaging has to be combined with fMRI to allow the exact anatomic location of the lesion and precise determination of the extension of the tumour. Perfusion and diffusion MR is becoming more and more important in the differential diagnosis of cerebral mass lesions and in the grading and typing of gliomas. More sophisticated techniques such as diffusion tensor imaging and spectroscopy will further enhance the value of the radiological studies.     

Treatment options in high-grade brain tumors: brain brachytherapy.

The extremely poor prognosis of high-grade brain tumors (glioblastoma multiforme and anaplastic astrocytomas) has been well documented in the literature. Almost 90% of patients die within 18 months after therapy, most commonly because of local persistence of the tumor, which may be controlled if a sufficient amount of irradiation can be delivered. Currently, postoperative radiation therapy offers the best median survival rate. However, the response to external-beam radiation therapy has reached a plateau because of the intolerance of healthy brain tissue to excessive irradiation. To treat these tumors, brachytherapy (interstitial implantation of radioactive sources) can be used with debulking surgery. This therapy is becoming an effective alternative to conventional external-beam radiation therapy, since it allows a higher dose to be delivered to the tumor bed without damaging the surrounding healthy brain tissue. With continual refinements of the technique, brachytherapy, performed by a skilled brachytherapy team, offers an opportunity to improve patient survival.     

Intra-axial brain tumors

Neuroradiology plays a key role in the diagnosis of brain tumors. Computed tomography (CT) and specially magnetic resonance imaging (MRI) allow accurate anatomic depiction of intracerebral lesions. The implementation of native and contrast studies allows the characterization of the various lesions encountered in the majority of cases. In this review the imaging aspects on CT and MRI of the most common primary intra-axial brain tumors will be discussed.