PET脑代谢-脑血流联合显像对肢体远隔缺血预适应治疗缺血性脑血管病疗效的评估价值

目的探讨正电子发射型断层扫描(PET)脑代谢-脑血流联合显像应用于肢体远隔缺血预适应(LRIC治疗缺血性脑血管病(ICVD)疗效的评估价值。方法回顾性分析2012年1月至2015年1月首都医科大学宣武医院神经外科收治的25例ICVD患者的~(18)F-FDG脑代谢和~(13)N-Ammonia脑血流PET显像结果,比较治疗前后PET影像以及脑代谢值、脑血流值、脑代谢减低率和脑血流减低率的变化。结果对于脑血流和/或脑代谢轻度受损的ICVD患者来说,LRIC的治疗基本有效,部分病灶脑代谢值或脑血流值恢复正常,治疗前后脑代谢值和脑血流值对比,差异有统计学意义(P 0. 05),特别是部分单纯轻度脑血流受损的ICVD患者,经过LRIC治疗后,病灶脑血流值均与健侧对比,差异无统计学意义(P0. 05);对于脑血流和/或脑代谢中度和部分重度受损的患者来说,多数病灶脑代谢和脑血流有所改善;对于部分脑血流和/或脑代谢严重受损的患者来说,LRIC治疗效果不明显。结论 PET脑代谢-脑血流联合显像是评价LRIC治疗ICVD疗效的良好方法,并具有较好的应用前景。     

轻度阿尔茨海默病患者脑代谢与脑血流影像变化

目的:观察轻度阿尔茨海默病患者脑18F-FDG PET影像特征,并与99Tcm-ECD SPECT脑血流显像进行对比.方法:选择2003-04/2004-05在首都医科大学附属宣武医院神经内科门诊就诊的阿尔茨海默病患者30例.其中轻度阿尔茨海默病患者15例,男6例,女9例;中重度阿尔茨海默病患者15例,男5例,女10例.选择同期来本院体检的健康体检者7例和阿尔茨海默病患者的配偶3例为正常对照组,全部受检者均行PET脑显像.9例正常人和9例轻度阿尔茨海默病患者于PET检查后1周内行99Tcm-ECD SPECT脑血流显像.利用计算机感兴趣区分析程度求出脑代谢比值和脑血流比值.结果:按意向处理分析,轻度、中重度阿尔茨海默病患者及正常对照组,均进入结果分析.①轻度阿尔茨海默病患者的脑代谢比值(左顶叶:1.08±0.02,左颢叶:1.04±0.06,右顶叶:1.09±0.06,右颞叶:1.07±0.07)和中重度阿尔茨海默病患者的脑代谢比值(左顶叶:0.93±0.05,左颞叶:0.98±0.05,左额叶:1.15±0.10,右顶叶:0.95±0.05,右颞叶:1.01±0.09,右额叶:1.05±0.08)均明显低于正常对照组[(左顶叶:1.21±0.15,左颞叶:1.19±0.11,左额叶:1.31±0.13,右顶叶:1.25±0.12,右颞叶:1.22±0.10,右额叶:1.34±0.14),(t=2.04～5.71,P＜0.05～0.01)].②轻度阿尔茨海默病患者的脑血流比值(左顶叶:0.81±0.04,左颞叶:0.79±0 12,右顶叶:0.86±0.10,右颞叶:0.83±0.08)均明显低于正常对照组[(0.90±0.06,0.89±0.09,0.87±0.07,0.93±0.08,0.91±0.07,0.92±0.08),(t=2 08～2.82,P＜0.05)].③15例中重度脑血流比值患者的PET显像,12例表现为双侧顶叶或双侧颞顶叶对称性放射性摄取减低[80%(12/50)],3例表现为单侧颞顶叶放射性减低[20%(3/15)].15例轻度阿尔茨海默病患者的PET显像,13例表现为单侧顶叶、单侧颞叶或单侧放射性摄取减低[87%(13/15)],2例表现为双侧顶叶放射性减低[13%(2/15)].9例轻度阿尔茨海默病患者的SPECT显像,6例出现单侧放射性摄取减低,3例患者的SPECT显像未见阳性发现.结论:轻度阿尔茨海默病患者既有脑代谢减低也有脑血流减低,脑葡萄糖乔代谢影像特征是以单侧顶叶、颞叶或颞顶叶小范围的代谢减低为主要表现,这种损害并不累及额叶,SPECT脑血流灌注显像可用于轻度阿尔茨海默病辅助诊断,其主要影像特征是出现单侧顶叶、颞叶或颞顶叶血流灌注减低,损害部位与PET显像发现的代谢减低区基本一致;但是应用SPECT脑血流灌注显像探测轻度阿尔茨海默病的灵敏度低于PET代谢显像,当SPECT显像阴性而临床可疑轻度阿尔茨海默病时,应进一步行PET显像.     

SPECT对缺血性脑血管病远隔缺血预适应的疗效评价研究

目的探讨单光子发射计算机断层(SPECT)显像对缺血性脑血管病(ICVD)患者在远隔缺血预适应疗效评价中的应用价值。方法 50例单侧颅内外动脉重度狭窄或闭塞的缺血性脑血管病患者,远隔缺血预适应(RIPC)治疗前后分别行SPECT脑血流灌注和脑葡萄糖代谢显像,分析RIPC治疗前后脑血流灌注及脑葡萄糖代谢显像病灶数量、脑血流量及脑代谢率的差异。结果 50例ICVD患者RIPC治疗后脑血流灌注异常病灶数量减少,47例(94.0%)血流灌注有不同程度增高;3例(6.0%)脑血流灌注增高患者有不同程度减低。50例ICVD患者RIPC治疗后脑葡萄糖代谢异常病灶数量增加,40例代谢减低的患者有34例(68.0%)不同程度代谢增高;10例代谢增高的患者有6例(12.0%)不同程度代谢减低。50例ICVD患者RIPC治疗前后SPECT显像比较,患侧额、顶、颞、枕叶、基底节和丘脑的血流灌注显著增高(P0.05);额、颞、枕叶、基底节和丘脑的葡萄糖代谢显著增高(P0.01),顶叶葡萄糖代谢增高无显著性差异(P0.05)。结论 SPECT脑血流灌注及脑葡萄糖代谢显像对评价RIPC治疗ICVD的疗效有重要价值。     

轻度阿尔茨海默病的PET与SPECT特征与对比

目的研究轻度阿尔茨海默病(AD)18F-FDG PET与99Tcm-ECD SPECT影像特征,并进行对比.方法受检者分为两组,正常对照组10例,轻度AD组 15例.利用ROI技术获得受检者的脑代谢比值(RARmetab)和脑血流比值(RARflow).结果与正常老年人比较,AD病人的RARmetab和RARflow减低,经统计学t检验均有显著性差异.结论轻度AD葡萄糖代谢影像特征是出现单侧顶叶、颞叶或颞顶叶代谢减低,额叶代谢保留在正常水平.SPECT脑血流显像特征与PET相似,但其灵敏度低于PET.     

轻度阿尔茨海默病患者脑代谢与脑血流影像变化

目的：观察轻度阿尔茨海默病患者脑^18F-FDG PET影像特征，并与^99Tc^m-ECD SPECT脑血流显像进行对比。方法：选择2003-04／2004-05在首都医科大学附属宣武医院神经内科门诊就诊的阿尔茨海默病患者30例。其中轻度阿尔茨海默病患者15例，男6例，女9例；中重度阿尔茨海默病患者15例，男5例，女10例。选择同期来本院体检的健康体检者7例和阿尔茨海默病患者的配偶3例为正常对照组，全部受检者均行PET脑显像、9例正常人和9例轻度阿尔茨海默病患者于PET检查后1周内行^99Tc^m-ECD SPECT脑血流显像。利用计算机感兴趣区分析程度求出脑代谢比值和脑血流比值结果：按意向处理分析，轻度、中重度阿尔茨海默病患者及正常对照组，均进入结果分析。①轻度阿尔茨海默病患者的脑代谢比值(左顶叶：1．08&;#177;0．02，左颞叶：1．04&;#177;0．06，右顶叶：1．09&;#177;0．06，右颞叶：1．07&;#177;0．07)和中重度阿尔茨海默病患者的脑代谢比值(左顶叶：0．93&;#177;0．05，左颞叶：0．98&;#177;0．05．左额叶：1．15&;#177;0．10．右顶叶：0．95&;#177;0．05，右颞叶：1．01&;#177;0．09，右额叶：1．05&;#177;O．08)均明显低于正常对照组[(左顶叶：1．2l&;#177;0．15．左颞叶：1．19&;#177;0．11．左额叶：1．31&;#177;0．13，右顶叶：1．25&;#177;0．12，右颞叶：1．22&;#177;0.10，右额叶：1．34&;#177;0．14)，(t=2．04-5．71，P&;lt;0．05-0．01)]、②轻度阿尔茨海默病患者的脑血流比值(左顶叶：0．8l&;#177;004，左颞叶：0．79&;#177;0．12，右顶叶：0．86&;#177;0．10，右颞叶：0．83&;#177;008)均明显低于正常对照组[(0．90&;#177;O．06，0．89&;#177;0．09，0．87&;#177;0．07，0．93&;#177;0．08．0．91&;#177;0.07．0．92&;#177;0．08)，(t=2．08-2．82，P&;lt;0.05)].③15例中重度脑血流比值患者的PET显像，12例表现为双侧顶叶或双侧颞顶叶对称性放射性摄取减低[80％(12／50)]，3例表现为单侧颞顶叶放射性减低[20％(3／15)115例轻度阿尔茨海默病患者的PET显像，13例表现为单侧顶叶、单侧颞叶或单侧放射性摄取减低[87％(13／15)]，2例表现为双侧顶叶放射性减低[13％(2／15)]。9例轻度阿尔茨海默病患者的SPECT显像，6例出现单侧放射性摄取减低，3例患者的SPECT显像未见阳性发现。结论：轻度阿尔茨海默病患者既有脑代谢减低也有脑血流减低．脑葡萄糖代谢影像特征是以单侧顶叶、颞叶或颞顶叶小范围的代谢减低为主要表现，这种损害并不累及额叶，SPECT脑血流灌注显像可用于轻度阿尔茨海默病辅助诊断，其主要影像特征是出现单侧顶叶、颞叶或颞顶叶血流灌注减低，损害部位与PET显像发现的代谢减低区基本一致；但是应用sPEcT脑血流灌注显像探测轻度阿尔茨海默病的灵敏度低于PET代谢显像，当sPEcT显像阴性而临床可疑轻度阿尔茨海默病时，应进一步行PET显像。     

缺血性脑血管疾病早期脑血流量和葡萄糖利用之间的关系

目的：通过比较脑血流灌注和脑葡萄糖代谢显像,观察在缺血性脑血管疾病中缺血程度与该部位葡萄糖代谢之间的关系。方法：对46例患有不同程度大脑中动脉狭窄的病人及15例正常对照组进行99Tcm-乙撑双半胱胺酸二乙酯（99Tcm-ECD）灌注显像和氟-18-脱氧葡萄糖（18F-FDG）细胞代谢符合线路显像进行比较分析。结果：病变部位呈现脑血流灌注减低而脑葡萄糖代谢增高的不匹配,差异有显著性（P〈0.05）。结论：缺血性脑血管病早期缺血部位血流灌注减低而葡萄糖摄取增高,并不代表神经元对葡萄糖的利用增高。     

成人颞叶癫痫患者发作间期18F-FDG PET/CT脑代谢显像与术后疗效的关系

目的:探讨成人颞叶癫痫患者发作间期18F-FDG PET/CT脑代谢显像与术后疗效的关系。方法:回顾性分析2013年8月-2018年3月于北部战区总医院接受发作间期18F-FDG PET/CT脑代谢显像,且颞叶均为阳性表现,并于我院神经外科接受手术治疗的颞叶癫痫患者62例,其中女22例,男40例,年龄范围18~58岁,平均(31.48±10.48)岁,按照病灶的数目(单发/多发)、侧别(单侧大脑半球/双侧大脑半球)将PET/CT图像分为单侧单发低代谢病灶组(病灶仅存在于单侧大脑半球颞叶中)、单侧多发低代谢病灶组(病灶存在于颞叶及其他同侧非颞叶中)、双侧多发低代谢病灶组(病灶分布于双侧颞叶或一侧颞叶与对侧非颞叶中),术后随访12~55(30.50±13.42)月,中位随访时间28.5月,根据Engel分级分为疗效满意组(EngelⅠ)45例和疗效不满意组(EngelⅡ+EngelⅢ+EngelⅣ)17例,对两组患者PET/CT图像中病灶的数目、侧别进行单因素分析,并对有统计学意义的因素进行Logistic回归分析,总结出18F-FDG PET/CT图像的代谢改变图型与成人颞叶癫痫患者术后预后的关系。结果:18F-FDG PET/CT脑代谢显像显示病灶的数目、侧别单因素分析结果均具有统计学意义,P值分别为0.001、0.02,进而进行Logistic回归分析,结果显示病变的数目与预后具有很强的相关性(OR=7.219,95%CI:0.339~8.676,P=0.008),而病变的侧别与预后不具有相关性(OR=1.714,95%CI:1.691~30.809,P=0.515)。结论:18F-FDG PET/CT脑代谢显像可用于预测成人颞叶癫痫患者的术后疗效,单发低代谢病灶的患者手术疗效较好,低代谢病灶的数目是手术预后疗效的独立预测因素。     

脑葡萄糖代谢显像诊断缺血性脑血管病

目的通过比较脑血流灌注显像和脑葡萄糖代谢显像,观察脑葡萄糖代谢显像在缺血性脑血管病诊断中的价值.方法对43例缺血性脑血管病患者和5例正常人的脑18氟-脱氧葡萄糖(18F-FDG)符合线路显像与99锝m-双半胱氨酸乙酯(99Tcm-ECD)脑血流灌注显像进行对比分析.结果脑葡萄糖代谢显像的灵敏度、特异度分别为71.81%、95.71%,脑血流灌注显像的灵敏度、特异度分别为57.45%(P＜0.01)、92.86%(P＞0.05).结论在诊断缺血性脑血管病中脑葡萄糖代谢显像较脑血流灌注显像更灵敏,故可用于早期诊断缺血性脑血管病.     

发作间期18F-FDG联合13N-NH3·H2O PET脑显像在颞叶内侧癫痫术前定位中的价值

目的：探讨发作间期18F-FDG联合13N-NH3·H2O PET脑显像在颞叶内侧癫痫术前定位中的价值。方法：收集行头部MRI、18F-FDG及13N-NH3·H2O PET/CT检查并经术中深部脑电图（DEEG）及皮层脑电图（ECoG）证实的颞叶内侧癫痫患者17例。所有PET图像采用感兴趣区（ROI）分析,对18F-FDG及13N-NH3·H2O PET显像结果进行比较。结果：18F-FDG PET显像对癫痫灶准确定侧12例（70.6%）,准确定位5例（29.4%）;13N-NH3·H2O PET显像准确定侧9例（52.9%）,准确定位4例（23.5%）。两种显像方法对癫痫灶定侧性能具有中度一致性（Kappa=0.638,P=0.005）,定侧准确性经McNemar检验,差异无统计学意义（P>0.05）。综合分析两种显像结果对癫痫灶准确定位8例（47.1%）。结论：发作间期18F-FDG PET显像对颞叶内侧癫痫有较高的定侧准确性,13N-NH3·H2O PET显像亦可以有效定侧颞叶癫痫。联合两种显像剂显像,优势互补,定位准确性明显提高,且癫痫灶低代谢、高灌注的表现使诊断特异性增加,更有助于颞叶癫痫灶的准确定位。     

~(18)F-FDGPET/CT脑显像鉴别帕金森病和多系统萎缩的临床价值

目的探讨~(18)F-FDG PET/CT脑显像对帕金森病(PD)和多系统萎缩(MSA)的鉴别诊断价值。方法回顾性分析临床诊断为PD(15例)和MSA(11例)的~(18)F-FDG PET/CT脑显像资料,首先对患者的脑代谢表现进行定性分析,然后使用Neuro Q软件进行定量分析其代谢模式差异。结果 15例PD患者~(18)F-FDG PET/CT脑显像,定性分析显示13例(86.7%)表现为皮层代谢减低;3例(20%)单侧壳核代谢减低,15例均未显示小脑代谢减低;定量分析显示全部患者均表现为大脑皮层受累,8例(53.3%)单侧壳核代谢减低,2例(13.3%)双侧壳核代谢减低,15例均未显示小脑代谢减低。11例MSA患者~(18)F-FDG PET/CT脑显像,定性分析显示全部患者表现为皮层代谢减低,4例(36.4%)壳核代谢减低;3例(27.3%)小脑代谢减低;定量分析显示全部患者表现为大脑皮层受累以及双侧壳核代谢减低;5例(45.5%)双侧小脑代谢减低。结论 ~(18)F-FDG PET/CT脑显像PD和MSA患者的基底节和小脑代谢模式存在差异,有助于临床进行鉴别诊断。     

一体化PET/MR评估脑血流量的研究进展

一体化PET/MR技术具有一次扫描可同时获得PET和MRI图像的独特优势,目前已逐步应用于临床。准确定量分析脑血流量（CBF）对研究脑血管病、脑肿瘤、癫痫等脑部重大疾病的发病机制及临床转归具有重要价值。一体化PET/MR可实现无创、简便、准确获得动脉输入函数,从而精准定量CBF。本文对一体化PET/MR评估CBF的研究进展进行综述。     

一体化18F-FDG PET/MR血流代谢显像评估慢性单侧头颈动脉狭窄

目的 观察一体化¹⁸F-PET/MR血流代谢显像评估单侧头颈动脉狭窄的价值。方法 纳入68例慢性单侧头颈动脉狭窄患者,记录其美国国立卫生研究院卒中量表（NIHSS）及改良Rankin量表（mRS）评分;采用一体化PET/MR同步采集MR结构像、动脉自旋标记图像和¹⁸F-FDG PET图像,基于血流、代谢图像获取并比较幕上病变侧血流减低区、代谢减低区、血流代谢同步减低区及其各项指标,分析其与临床神经功能评分的相关性。结果 68例患者中,与血流减低区比较血流代谢同步减低区脑血流量（CBF）更低（P<0.001）、不对称指数（AI）更高（P<0.001）;血流代谢同步减低区与代谢减低区标准摄取值比值（SUVR）差异无统计学意义（P=0.548）,但前者AI更高（P<0.001）。同步减低区体积比与NIHSS、mRS均呈正相关（r_s=0.507、0.467,P均<0.001）,SUVR AI与NIHSS、mRS均呈正相关（r_s=0.337、0.317,P均<0.05）。结论 一体化PET/MR可检出慢性单侧头颈动脉狭窄患者脑血流和脑葡萄糖代谢异常。     

允许性高碳酸血症机械通气对新生猪脑血流的影响

目的 探讨允许性高碳酸血症(PHC)对急性呼吸衰竭新生猪机械通气时脑血流及组织代谢的影响.方法 18只新生猪随机(随机数字法)分为PHC组、标准碳酸血症(NC)组、健康对照组(Control);PHC(PaCO250～60 mmHg)与NC组(PaCO2 35～45 mmHg)以胎粪致急性呼吸衰竭,机械通气;每组6只.应用彩色微球示踪技术,测定脑组织血流速度(CBF),脑组织氧代谢率(CMRO2)、脑组织糖代谢率(CMRGlu)、脑组织乳酸生成率(CLP).结果 NC组新生猪在机械通气6 h,12 h时点CBF较Control组显著降低(P＜0.05);12 h时点CMRGlu及CLP较Control组升高,CMRO2较Control组降低;CBF/CMRGlu及CBF/CLP比值在6 h及12 h均较Control组降低(P＜0.05).NC组CBF/CMRO2与Control组相比,差异具有统计学意义(P＞0.05).PHC组在6 h CBF较Control组降低;12h时点,PHC组CBF与Control组相比,差异无统计学意义;PHC组各时点CMRO2,CMRGlu,CLP与Control组相比,差异均无统计学意义.CBF/CMRGlu及CBF/CLP比值在机械通气6 h,12 h时点,PHC组低于Control组,但与NC组相比,下降程度已减少(P＜0.05);PHC组CBF/CMRO2与Control组相比,差异无统计学意义.结论 急性呼吸衰竭新生猪予正常碳酸血症水平机械通气时,CBF降低,存在脑血流-代谢调节障碍.PHC可减轻CBF下降,改善急性呼吸衰竭新生猪在正压通气时的脑血流-代谢调节障碍.

Abstract：

Objective To investigate the effects of permissive hypercapnia (PHC) strategy used in ventilated newborn swine with respiratory failure on cerebral blood flow (CBF) and tissue metabolism. Method Eighteen newborn swine were randomly (random number) divided into 3 groups (n = 6): PHC, normocapnia (NC) and normal control groups. In PHC (PaCO2 50～60 mmHg) and NC (PaCO2 35 ～ 45 mmHg) groups, newborn swine were ventilated for treating respiratory failure induced by meconium aspiration. CBF was measured by using colored microsphere tracking technique. Cerebral oxygen metabolism rate (CMRO2), cerebral glucose metabolism rate (CMRGlu), and cerebral lactate production (CLP) were measured. Results After ventilation for 6 hours and 12hours, CBF in NC group decreased more significantly than those did in control group, and CMRGlu and CLP increased more significantly than those did in control group. In NC group, CMRO2 decreased more prominently than it did in control group 12 hours later. The CBF/CMRGlu and CBF/CLP ratios in NC group were lower than those in control(P＜0.05). There was no significant difference in CBF/CMRO2 ratio between NC and control groups. After ventilation for 6 hours, CBF in PHC group was lower than those in control group. But after ventilation for 12hours, CBF in PHC group increased and there was no significant difference in CBF between PHC group and control group (P＞O.05). There were no significant differences in CMRGlu, CLP and CMRO2 between PHC group and control group. The CBF/CMRGlu and CBF/CLP ratios in PHC group were lower than those in control, but higher then those in NC group (P＜0.05). There was no significant difference in CBF/CMRO2 ratio between PHC and control groups. Conclusions The reduction of cerebral blood flow and the disturbance of CBF autoregulation disturbance occur in ventilated newborn swine with hypoxemia respiratory failure. PHC may attenuate the reduction in CBF and the disturbance of CBF autoregulation.     

核素显像及磁共振灌注成像在诊断缺血性脑血管病中的对比研究

目的比较脑葡萄糖代谢显像、脑血流灌注显像及磁共振灌注成像三种检查方法在诊断缺血性脑血管病中的价值。方法对78例缺血性脑血管病患者和26例单侧脑血管病变患者的脑葡萄糖代谢显像、脑血流灌注显像及磁共振灌注成像进行对比分析。结果所有患者用脑葡萄糖代谢显像、脑血流灌注显像及磁共振灌注成像三种检查方法检出的阳性率分别为97.44%、94.87%和82.05%,脑葡萄糖代谢显像、脑血流灌注显像与灌注加权磁共振成像结果比较均有显著性差异(P值分别为0.012、0.002)。26例单侧血管病变患者用三种检查方法检出的阳性率分别为96.15%、92.31%、92.31%,三者无显著性差异(P=0.552)。结论脑葡萄糖代谢显像、脑血流灌注显像对诊断缺血性脑血管病较敏感,在诊断单侧血管病变中三种检查方法均较敏感。     

氙CT评价颈内和大脑中动脉狭窄或闭塞的脑血流研究

目的探讨颈内/大脑中动脉慢性狭窄、闭塞患者的氙CT脑血流成像表现及其临床应用价值。方法20例颈内/大脑中动脉慢性重度狭窄或闭塞患者行氙CT脑血流成像检查,2例行乙酰唑胺负荷试验。计算出脑血流图,进行定性和定量分析。结果20例颈内/大脑中动脉慢性重度狭窄或闭塞患者,10例单侧ICA/MCA重度狭窄或闭塞患者,7例发现病变侧CBF轻度下降,但无显著性差异(P>0.05)。10例单侧ICA/MCA闭塞,对侧重度狭窄患者,9例CBF图发现异常改变,表现为闭塞侧CBF下降较狭窄侧降低明显(P<0.05);闭塞侧CBF值与单侧病变患者的正常侧比较有显著性差异(P<0.05)。2例行乙酰唑胺负荷试验患者,负荷后CBF降低较负荷前明显。结论氙CT检查能够显示颈内/大脑中动脉慢性重度狭窄或闭塞脑血流情况,有利于临床的诊断和治疗。     

Quantification of pain-induced changes in cerebral blood flow by perfusion MRI

The purpose of this study was to assess if the functional activation caused by painful stimuli could be detected with arterial spin labeling (ASL), which is a non-invasive magnetic resonance imaging (MRI) technique for measuring cerebral blood flow (CBF). Because ASL directly measures blood flow, it is well suited to pain conditions that are difficult to assess with current functional MRI, such as chronic pain. However, the use of ASL in neuroimaging has been hampered by its low sensitivity. Recent improvements in MRI technology, namely increased magnetic field strengths and phased array receiver coils, should enable ASL to measure the small changes in CBF associated with pain. In this study, healthy volunteers underwent two ASL imaging sessions, during which a painful thermal stimulus was applied to the left hand. The results demonstrated that the ASL technique measured changes in regional CBF in brain regions that have been previously identified with pain perception. These included bilateral CBF changes in the insula, secondary somatosensory, and cingulate cortices, as well as the supplementary motor area (SMA). Also observed were contralateral primary somatosensory and ipsilateral thalamic CBF changes. The average change in CBF for all regions of interest was 3.68 ml/100 g/min, ranging from 2.97 ml/100 g/min in ipsilateral thalamus to 4.91 ml/100 g/min in contralateral insula. The average resting global CBF was 54 ± 9.7 ml/100 g/min, and there was no change in global CBF due to the noxious thermal stimulus.     

肝移植术后脑病患者围手术期脑氧代谢的特点

目的 观察肝移植患者围手术期脑氧代谢指标变化的规律,分析术后并发脑病者的脑氧代谢特点及与术后脑病发生的关系.方法 观察并追踪肝移植患者30例,根据术后是否发生脑病分为两组,分别于术前、无肝25 min及新肝30 min、新肝3 h、新肝24 h抽取桡动脉和左颈静脉血进行血气分析,计算动脉血氧含量(CaO2)、颈静脉血氧含量(CjvO2)、动脉-颈静脉血氧含量差(Ca-jvO2)、脑氧摄取率(CERO2)、脑血流量/脑氧代谢率比值(CBF/CMRO2)等脑氧代谢指标,同时测定血糖、乳酸含量.结果 30例肝移植患者中有11例(占36.7%)术后出现了脑病症状.脑病组术中红细胞输入量、出血量和去甲肾上腺素用量均高于非脑病组.两组脑氧代谢指标整体变化趋势一致,CaO2、Ca-jvO2在无肝25 min、新肝30 min、新肝3 h时,CERO2在新肝30 min、新肝3 h时均较术前显著降低[CaO2(ml/L):脑病组132.4±23.5、125.9±17.6、133.4±11.1比148.5±28.8,非脑病组135.7±22.4、130.5±20.0、139.9±21.2比148.9±28.2;Ca-jvO2(ml/L):脑病组42.9±13.2、31.4±12.3、32.3±6.5比52.9±23.5,非脑病组33.0±14.1、26.6±9.1,30.6±10.3比50.2±23.2;CERO2:脑病组(24.9±9.7)%、(24.4±5.5)%比(35.4±11.5)%,非脑病组(20.6±7.3)%、(21.9±7.0)%比(33.4±13.1)%,均P<0.05],在新肝24 h时恢复至术前水平;颈静脉血氧饱和度(SjvO2)、CBF/CMRO2比值在新肝30 min、新肝3 h时均较术前显著增高(SjvO2:脑病组0.838±0.105、0.835±0.065比0.709±0.125,非脑病组0.854±0.074、0.824±0.074比0.713±0.138;CBF/CMRO2比值:脑病组37.8±16.6、31.9±6.8比20.9±6.7,非脑病组37.8±14.1、35.7±13.7比24.3±14.0,均P<0.05),在新肝24 h时恢复至术前水平.两组血糖、乳酸含量整体变化趋势一致,血糖在无肝期至新肝24 h均较术前显著升高;乳酸含量在无肝期至新肝3 h显著高于术前,至新肝24 h时恢复至术前水平.结论 肝移植围手术期脑氧代谢发生异常变化,但脑病组并无特异性.肝移植术后脑病的发生是多因素的,预防和治疗上要综合考虑.

Abstract：

Objective To investigate the feature of cerebral oxygen metabolism during peri-operative stage of orthotopic liver transplantation(OLT),in order to identify the difference between the patients with or without complicating encephalopathy after OLT,and the relationship between the cerebral oxygen metabolism and encephalopathy after OLT.Methods Thirty patients undergoing OLT were studied.The patients were divided into two groups according to occurrence or not of encephalopathy after OLT:encephalopathy group and non-encephalopathy group. Blood samples were taken from radial artery and jugular vein simultaneously for blood gas analysis before operation,25 minutes after onset of anhepatic phase,30 minutes after graft reperfusion,3 hours after graft reperfusion,and 24 hours after graft reperfusion.Cerebral arterial oxygen content(CaO2),oxygen content of jugular vein blood(CjvO2),cerebral arterial-venous oxygen content difference(Ca-jvO2),cerebral oxygen extraction ratio(CERO2)and cerebral blood flow/cerebral metabolic rate of oxygen ratio(CBF/CMRO2)were calculated,and the levels of blood glucose and lactic acid were recorded.Results There were 11 patients(36.7%)complicated by encephalopathy after OLT.The quantity of red blood cell infusion,blood loss and the dosage of noradrenalin in encephalopathy group were significantly larger compared with non-encephalopathy group.The overall tendency of change in cerebral oxygen metabolism index was about the same for both groups,while CaO2 and Ca-jvO2 at 25 minutes after onset of anhepatic phase,30 minutes after graft reperfusion and 3 hours after graft reperfusion,and CERO2 at 30 minutes after graft reperfusion and 3 hours after graft reperfusion were significantly decreased compared with those before operation(CaO2(ml/L)in encephalopathy group:132.4±23.5,125.9±17.6,133.4±11.1 vs.148.5±28.8,in non-encephalopathy group:135.7±22.4,130.5±20.0,139.9±21.2 vs.148.9±28.2; Ca-jvO2(ml/L)in encephalopathy group: 42.9±13.2,31.4±12.3,32.3±6.5 vs.52.9±23.5,in non-encephalopathy group:33.0±14.1,26.6±9.1,30.6±10.3 vs.50.2±23.2; CERO2 in encephalopathy group:(24.9±9.7)%,(24.4±5.5)%vs.(35.4±11.5)%,in non-encephalopathy group:(20.6±7.3)%,(21.9±7.0)%vs.(33.4±13.1)%,all P<0.05],and they returned to the levels before operation at 24 hours after graft reperfusion.Jugular venous oxygen saturation(SjvO2)and CBF/CMRO2 ratio were significantly increased at 30 minutes after graft reperfusion and 3 hours after graft reperfusion compared with the levels before operation [SjvO2 in encephalopathy group:0.838±0.105,0.835±0.065 vs.0.709±0.125,in non-encephalopathy group:0.854±0.074,0.824±0.074 vs.0.713±0.138;CBF/CMRO2 ratio in encephalopathy groupl 37.8±16.6,31.9±6.8 vs.20.9±6.7,in non-encephalopathy group:37.8±14.1,35.7±13.7 vs.24.3±14.0,all P<0.05],and they returned to the levels before operation at 24 hours after graft reperfusion.The overall tendency of change in blood glucose and lactic acid was about the same in both groups,while the levels of blood glucose increased significantly from anhepatic phase to 24 hours after graft reperfusion compared with the levels before operation,and the levels of lactic acid increased significantly from anhepatic phase to 3 hours after graft reperfusion compared with the levels before operation and returned to the levels before operation at 24 hours after graft reperfusion.Conclusion There are significant changes in the features of cerebral oxygen metabolism during OLT,but there is no difference between encephalopathy group and non-encephalopathy group.The occurrence of encephalopathy can be attributed to many factors,so the prevention and treatment should be comprehensive considered.     

蝙蝠脑血流的磁共振脑灌注成像测量

目的 建立一种能定量测量蝙蝠脑血流(CBF)的连续动脉血标记磁共振灌注成像方法.方法 采用 spiral快采样方式以降低磁场不均匀性对成像结果的影响,并同时提高CBF测量的时间分辨率.以所建立的方法测量棕果蝠和几内亚长翼蝠的脑血流.结果 在异氟醚麻醉下,棕果蝠丘脑和皮层的脑血流分别为(1.51±0.21)ml/(min·g)和(0.75±0.29)ml/(min·g);而几内亚长翼蝠丘脑和皮层的脑血流分别为(2.30±0.36)ml/(min·g)和(1.17±0.17)ml/(min·g).结论 蝙蝠丘脑和皮层中局部脑血流的不同可能反应了麻醉状态下这两个脑区中代谢水平的高低.     

Changes in arterial and cerebral venous blood gases, cerebral blood flow and cerebral oxygen consumption at different stages of thioacetamide-induced hepatogenic encephalopathy in rat

Rats were subjected to repeated intraperitoneal administrations of thioacetamide (TAA) in order to produce the following stages of hepatogenic encephalopathy (HE): the early stage, characterized by activation of brain metabolism (Group 1), the precomatose stage with impairment of brain metabolism (Group 2) and the stage of recovery (Group 3). A decrease of cerebral blood flow (CBF) of 50%, related to a drop of systemic arterial pressure and to increased hematocrit, were observed in groups 1 and 2 but not in group 3. However, the cerebral oxygen consumption (CMRO2), calculated from arterial venous difference in oxygen content and taking into account CBF, was markedly decreased in group 2, but remained unchanged in group 1. This reflects the state of cerebral metabolism at these stages. The results underscore the necessity of simultaneous monitoring of CBF and blood gases for distinguishing between the particular stages of HE revealed by biochemical tests.