磁共振波谱与洛文斯顿认知评定量表在脑卒中后认知功能评定中的相关性分析

目的 探讨脑卒中后认知障碍患者磁共振波谱（MRS）与洛文斯顿认知评定量表评分的相关性,分析其临床意义。 方法 采用简易精神状态检查量表(MMSE)筛查脑卒中认知障碍患者30例(认知障碍组)和脑卒中无明显认知障碍患者30例(卒中对照组),另选30例健康志愿者作为健康对照组。3组间性别、年龄、文化程度、病程等一般资料均相匹配,3组均行MRS检查及LOTCA评定,比较3组评定结果,分析MRS与LOTCA相关性。 结果 ①认知障碍组LOTCA总分及各项评分均低于卒中对照组和健康对照组(P<0.05),卒中对照组LOTCA总分及定向力、空间知觉、视运动组织、思维运作各项评分低于健康对照组(P<0.05),而视知觉和动作运用评分低于健康对照组,但差异无统计学意义（P>0.05）。②认知障碍组双侧海马区NAA/Cr低于卒中对照组和健康对照组(P<0.05),双侧海马区Cho/Cr高于卒中对照组和健康对照组(P<0.05),卒中对照组双侧海马区NAA/Cr低于健康对照组（P<0.05）,双侧海马区Cho/Cr高于健康对照组（P<0.05）。③左侧海马区NAA/Cr与LOTCA总分、各分项及注意力评分呈低至中度正相关(r＝0.376～0.661,P<0.05);右侧海马区NAA/Cr与LOTCA总分、各分项及注意力呈低至中度正相关(r＝0.396～0.691,P<0.05);左侧海马区Cho/Cr与LOTCA总分及各分项呈低至中度负相关(r＝-0.368～-0.619,P<0.05),与注意力无明显相关性(r＝-0.312,P>0.05);右侧海马区Cho/Cr与LOTCA总分及定向力、视知觉、视运动组织及思维运作呈低至中度负相关(r＝-0.391～-0.632,P<0.05),与空间知觉、动作运用及注意力无明显相关性(r＝-0.263,r＝-0.339,r＝-0.219,P>0.05)。 结论 MRS用于评定脑卒中患者的认知功能可有效鉴别认知障碍的存在,MRS与LOTCA评分具有相关性,两者结合能更全面和客观地评价认知功能障碍。     

帕金森病患者脑部氢质子MR波谱研究

目的应用氢质子磁共振波谱技术(1HMRS)检测帕金森病(PD)患者脑部代谢物变化。材料与方法搜集PD患者42例、健康体检者20例临床资料,进行头颅磁共振(MRI)和磁共振波谱(MRS)检查,测定中脑黑质、大脑苍白球、前额叶、海马区、楔回、背侧丘脑的脑代谢物N-乙酰天冬氨酸/肌酸(NAA/Cr)、N-乙酰天冬氨酸/胆碱化合物(NAA/Cho)、胆碱化合物/肌酸(Cho/Cr)比值;比较两组代谢物的差异性以及代谢物变化与UPDRS评分、病程的相关性。结果 (1)PD组NAA/Cr、NAA/Cho在双侧中脑黑质、苍白球、前额叶、海马区、楔回、背侧丘脑均显著低于对照组(P0.01);Cho/Cr在右侧海马区、右侧楔回、右背侧丘脑均高于对照组(P0.05)。(2)PD组双侧黑质(左r=–0.324,P=0.036,右r=–0.399,P=0.009)、右侧苍白球(r=–0.353,P=0.022)、左海马区(r=–0.388,P=0.011)、左楔回(r=–0.325,P=0.036)NAA/Cho与UPDRS呈负相关(均P0.05);(3)左侧苍白球Cho/Cr比值与病程呈正相关(r=0.327,P=0.034)。结论 PD患者脑部存在广泛神经元损害伴有部分胶质增生,脑代谢异常与临床病情严重程度正相关,并随病程的延长而逐渐加重。     

2型糖尿病患者认知功能及海马氢质子磁共振波谱研究

目的 探讨2型糖尿病(T2DM)患者与健康对照者(HC)认知功能与双侧海马代谢的异同.方法 应用多维度神经心理测试对比评估21例T2DM患者和19名HC的神经认知功能;并采用氢质子磁共振波谱(1H-MRS)检测双侧海马氮-乙酰天门冬氨酸复合物(NAA),胆碱复合物(Cho)与肌酸(Cr)的比值.结果 ①T2DM组听觉词语记忆测试-延迟回忆项(AVLT-delay recall)、听觉词语记忆测试-再认回忆项(AVLT-recognition)和画钟测试(CDT)成绩均显著地低于HC组(P均<0.05),并与糖化血红蛋白(HbAlc)呈负相关;②T2DM患者双侧海马NAA/Cr降低(均P<0.01),并以左侧为著(P<0.05);左侧海马Cho/Cr增高(P<0.05);③双侧海马代谢指标与T2DM患者BMI、FBG和HbAlc呈负相关;左侧海马NAA/Cr与AVLT-Delay Recall成绩正相关.结论 T2DM可引起海马代谢异常及多项认知功能损害,且左侧海马代谢异常可能与记忆损害密切相关.     

~1H-MRS和临床相关因素在新生儿脑白质弥漫性高信号诊断中的应用价值

目的运用单体素氢质子波谱技术(1H-MRS)观察新生儿脑白质弥漫性高信号(DEHSI)成像特点,探讨DEHSI的演变规律及诊断价值。材料与方法对95名新生儿运用点分辨波谱序列对其脑组织兴趣区所得代谢数据进行分析研究。结果生后年龄、胎龄、头围均与DEHSI评估之间呈显著负相关(r=-0.398、r=-0.390、r=-0.269,P值均0.05)。胎龄、生后年龄与NAA/Cr(r=0.386、r=0.328,P值均0.05),NAA/Cho(r=0.432、r=0.367,P值均0.05)呈正相关,与Cho/Cr(r=-0.204、r=-0.211,P值均0.05),MI/Cr(r=-0.243、r=-0.286,P值均0.05)呈负相关。此外,随着DEHSI的程度增加,NAA浓度,NAA/Cr和NAA/Cho比值下降(r=-0.320、r=-0.394、r=-0.565,P值均0.05),而Cho/Cr和MI/Cr增加(r=0.389、r=0.376,P值均0.05)。单因素方差分析:与正常组相比,轻度DEHSI组及中重度DEHSI组Cho/Cr和MI/Cr比值显著升高(P值均0.05),而NAA/Cr、NAA/Cho比值显著下降(P值均0.05)。结论生后年龄、胎龄、头围与DEHSI评估之间呈负相关;胎龄及生后年龄与新生儿脑组织代谢物水平有关;胎龄越大,胎儿越成熟,DEHSI分级越低,NAA浓度升高。     

脑星形细胞瘤磁共振波谱与肿瘤细胞Survivin、PCNA相关性研究

目的 探讨脑星形细胞瘤磁共振波谱(MRS)与肿瘤细胞的Survivin 蛋白、细胞核增殖抗原(PCNA)蛋白表达的相关性.方法 对照观察50例脑星形细胞瘤MRS检查结果与免疫组化方法测定术后标本的Survivin、PCNA蛋白表达,分析肿瘤实质内最大Cho/NAA、Cho/Cr和最小NAA/Cr值与肿瘤级别的关系,并分别与PCNA增殖指数(PI)、Survivin免疫活性指数(IRS)进行相关性分析.结果 高级别星形细胞瘤的Cho/Cr和Cho/NAA高于低级别星形细胞瘤和对照组,NAA/Cr低于低级别星形细胞瘤和对照组.Survivin的IRS和PCNA的PI随着肿瘤恶性度增加而升高.星形细胞瘤Cho/Cr与IRS显著正相关(r=0.745,P<0.01);星形细胞瘤Cho/NAA与IRS显著正相关(r=0.753,P<0.01).星形细胞瘤Cho/Cr与PI显著正相关(r=0.818,P<0.01);星形细胞瘤Cho/NAA与PI显著正相关(r=0.760,P<0.01).星形细胞瘤NAA/Cr与IRS呈负相关(r=-0.374,P<0.01),星形细胞瘤NAA/Cr与PI呈负相关(r=-0.436,P<0.01).结论 MRS基本反映着肿瘤细胞PCNA及Survivn表达情况,可在术前预测肿瘤凋亡抑制情况、增殖潜能、侵袭能力和预后,其中Cho/Cr,Cho/NAA较NAA/Cr更有意义.     

正常中年人海马MR波谱相关参数分析

目的应用氢质子磁共振波谱(1H-MRS)技术,分析正常中年人双侧海马在不同年龄组、不同部位各代谢物比值变化规律,为临床早期诊断及治疗海马相关性疾病提供参考依据。材料与方法从社区健康志愿者中选取符合标准者276名,按年龄分3组,A组:壮实期(41~48岁)90名,B组:稳健期(49~55岁)93名,C组:调整期(56~65岁)93名,行常规颅脑MR平扫、双侧海马MRS扫描,计算双侧海马头、体、尾部NAA/Cr、Cho/Cr、NAA/(Cho+Cr)值,分析不同性别间、左右侧别间、各年龄组间及同年龄组不同部位间各参数的差异及各参数与年龄的相关性。结果 NAA/Cr、Cho/Cr、NAA/(Cho+Cr)值在男女之间、左右侧别间差异无统计学意义(P0.05);各年龄组间相同部位差异有统计学意义(P0.05),NAA/Cr、NAA/(Cho+Cr)值A、B组均高于C组(P0.05),Cho/Cr值A组低于C组(P0.05);NAA/Cr、Cho/Cr值在同年龄组不同部位间差异有统计学意义(P0.05),NAA/Cr值在A、B、C组海马头、体部均高于尾部(P0.05),Cho/Cr值A、B组海马体部均高于尾部。NAA/Cr、NAA/(Cho+Cr)值与年龄呈负相关(r值分别为-0.486、-0.653,P0.05);Cho/Cr值与年龄呈正相关(r值为0.482,P0.05)。结论 ~1H-MRS能反映正常中年人海马不同部位代谢物相对含量的变化,为早期临床诊断及治疗海马相关性疾病提供参考依据。     

青中年维持性血液透析患者海马代谢异常的1H-MRS研究

目的:应用氢质子磁共振波谱技术(¹H-MRS)研究青中年维持性血液透析(MHD)患者海马代谢异常。方法:选择39例青中年MHD患者(透析组)及27例年龄、教育程度相匹配的健康志愿者(对照组)。所有受试者先行蒙特利尔认知评估(Mo-CA)及听觉词语测试(AVLT-H);进而行全脑3D结构像磁共振扫描,选取双侧海马为中心点,构建大小为1.0 cm×2.5 cm×1.0 cm的感兴趣区(ROI),进行单体素¹H-MRS扫描,获得双侧海马的NAA峰、Cho峰、Cr峰、NAA/Cr值、Cho/Cr值;同时采集透析组实验室指标,包括血红蛋白、红细胞压积、血肌酐、血尿素、白介素6及甲状旁腺激素;使用SPSS 19.0软件包对双侧海马波谱数据及实验室指标进行统计分析。结果:两组间MoCA得分、AVLT-H各子项得分均无显著性差异(P均>0.05)。较对照组相比,透析组左侧海马Cho峰增高(P=0.002)及NAA/Cr峰减低(P=0.006),右侧海马Cho峰增高(P=0.007)及Cho/Cr峰增高(P=0.006)。Pearson相关性分析显示:透析组右侧海马Cho/Cr峰与血尿素(r=0.522,P=0.001)及血肌酐(r=0.514,P=0.001)呈显著正相关。结论:青中年MHD患者虽无记忆及整体认知损伤,但存在双侧海马代谢异常改变,并与其血尿素及肌酐蓄积密切相关,可为后续进一步预防或干预中青年终末期肾病认知功能障碍进展提供影像学证据及监测指标。     

血管性痴呆不同中医证型磁共振波谱特点

目的:探讨血管性痴呆(VD)患者不同中医证型磁共振波谱(1H-MRS)检查特点。方法:对VD肾精亏虚、痰浊阻窍、瘀血阻络患者各15例,行头颅1H-MRS检查,测得N-乙酰天门冬氨酸(NAA)、乙酰胆碱(Cho)、肌酸(Cr)及NAA/Cr、Cho/Cr。结果:其中右侧丘脑中Cho/Cr及NAA/Cr3组比较未见明显差异。左侧丘脑中NAA/Cr肾精亏虚组低于瘀血阻络组(P0.05);3组Cho/Cr比较未见明显差异。右侧额叶中Cho/Cr痰浊阻窍组高于瘀血阻络组(P0.05);肾精亏虚证患者NAA/Cr比值明显低于痰浊阻窍组(P0.01)和瘀血阻络组(P0.05)。左侧额叶中Cho/Cr痰浊阻窍组高于瘀血阻络组(P0.05);肾精亏虚证患者NAA/Cr比值明显低于痰浊阻窍组(P0.05)和瘀血阻络组(P0.01)。右侧海马Cho/Cr痰浊阻窍组高于其他2组(P0.01);3组NAA/Cr比较未见明显差异。左侧海马中Cho/Cr及NAA/Cr3组比较未见明显差异。结论:肾精亏虚证、痰浊阻窍证及瘀血阻络证患者的1H-MRS有不同表现。其中,肾精亏虚证患者双侧额叶NAA/Cr水平较其他2组下降,可作为其诊断成立的依据之一。痰浊阻窍证患者双侧额叶及海马Cho/Cr较其瘀血阻络组有不同水平的升高,可作为鉴别诊断。     

孤独症患儿神经连接异常的影像特征

目的 联合应用弥散张量成像(DTI)和磁共振波谱(MRS)技术分析孤独症患儿大脑白质的结构和功能,探讨孤独症患儿神经连接异常的影像学特征。方法 对符合入选标准的2~9岁孤独症患儿(孤独症组,n= 14)和健康儿童(对照组,n= 8)分别进行DTI和MRS检测,以双侧额叶、胼胝体膝部及压部、海马、小脑白质为感兴趣区,利用GEAW 4.2工作站的Functool 2.6软件分别对DTI及MRS数据进行后处理分析,分别记录DTI的各向异性分数(FA)、表观弥散系数(ADC),MRS的代谢物N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酐(Cr)绝对浓度以及NAA/Cr、Cho/Cr比值。结果 与对照组相比,孤独症组左海马FA降低(F= 5.922, P = 0.033),左右海马Cr降低(F> 4.715,P < 0.05)。孤独症组左侧胼胝体膝部FA低于右侧( F = -2.335, P = 0.042),左侧胼胝体压部ADC明显高于右侧(F = 3.520, P < 0.01);左侧额叶NAA、Cho、Cr绝对浓度(| t| > 2.648, P < 0.05),胼胝体压部NAA绝对浓度( t= -3.076, P = 0.009),小脑Cho/Cr均低于右侧(t= -2.225, P = 0.044)。对照组左右半球相对脑区DTI和MRS检测值均无显著性差异(P > 0.05)。 结论 孤独症患儿额叶、海马、小脑、胼胝体膝部及压部存在局部代谢或功能的异常,提示孤独症患儿可能存在半球内尤其左侧大脑半球内神经连接不足,半球间神经连接不足。     

轻度阿尔茨海默病和血管性痴呆患者认知损害及与扣带回后部和海马氢质子磁共振波谱的相关性研究

目的分析轻度阿尔茨海默病(AD)和血管性痴呆(VD)患者的认知损害程度及与氢质子磁共振波谱(1H-MRS)的关系,探讨其对AD与VD的诊断和鉴别诊断的作用。方法 AD组28例、VD组30例、健康对照组22例,采用简易精神状态量表(MMSE)、蒙特利尔认知评估量表(Mo CA)进行认知功能评分;采用刺激回波序列进行检测,计算双侧海马和扣带回后部的N-乙酰天冬氨酸/肌酸(NAA/Cr)、肌醇/肌酸(MI/Cr)、胆碱/肌酸(Cho/Cr)、N-乙酰天冬氨酸/肌醇(NAA/MI)等的比值;比较各组间认知功能评分和各代谢物比值的差别,并进行相关分析。结果 (1)AD组和VD组的Mo CA总分、MMSE评分均低于对照组,差异有统计学意义(P<0.05);VD组汉密尔顿焦虑量表(HAMA)评分高于AD组和对照组(P<0.05);(2)AD组和VD组左侧海马、扣带回后部的NAA/Cr比值均低于对照组(P<0.05);AD组和VD组扣带回后部的Cho/Cr比值低于对照组;AD组和VD组左侧海马、扣带回后部的MI/Cr比值高于对照组(P<0.05);AD组和VD组左侧海马、扣带回后部的NAA/MI比值均低于对照组(P<0.05)。与VD组相比,AD组左侧海马、扣带回后部的NAA/Cr比值升高,差异有统计学意义(P<0.05),扣带回后部的Cho/Cr比值降低,差异有统计学意义(P<0.05),左侧海马、扣带回后部的MI/Cr比值升高,差异有统计学意义(P<0.05);(3)AD组和VD组的Mo CA总分、MMSE评分与左侧海马、扣带回后部的NAA/Cr存在正相关(P<0.05),AD组MMSE评分与扣带回后部的NAA/MI存在正相关(P<0.05),而VD组MMSE评分与扣带回后部的NAA/MI无相关性(P>0.05)。结论在认知损害程度方面轻度AD患者与VD患者具有相似性,且认知损害程度与左侧海马、扣带回后部的1H-MRS具有相关性,认知功能评分与1H-MRS结合可作为AD和VD早期诊断、鉴别诊断的重要工具。     

Parallel transport in diffeomorphisms distinguishes the time-dependent pattern of hippocampal surface deformation due to healthy aging and the dementia of the Alzheimer's type

Hippocampal surface structure was assessed at twice 2 years apart in 26 nondemented subjects (CDR 0), in 18 subjects with early dementia of Alzheimer type (DAT, CDR 0.5), and in 9 subjects who converted from the nondemented (CDR 0) to the demented (CDR 0.5) state using magnetic resonance (MR) imaging. We used parallel transport in diffeomorphisms under the large deformation diffeomorphic metric mapping framework to translate within-subject deformation of the hippocampal surface as represented in the MR images between the two time points in a global template coordinate system. We then performed hypothesis testing on the longitudinal variation of hippocampal shape in the global template. Both subjects with early DAT and converters showed greater rates of hippocampal deformation across time than nondemented controls within every subfield of the hippocampus. In a random field analysis, inward surface deformation across time occurred in a non-uniform manner across the hippocampal surface in subjects with early DAT relative to the nondemented controls. Also, compared to the controls, the lateral aspect of the left hippocampal tail showed inward surface deformation in the converters. Using surface deformation patterns as features in a linear discriminant analysis, we were able to respectively distinguish converters and patients with early DAT from healthy nondemented controls at classification rates of 0.77 and 0.87, which were obtained in the same training set using the leave-one-out cross validation approach.     

Changes in hippocampal volume and shape across time distinguish dementia of the Alzheimer type from healthy aging

Rates of hippocampal volume loss have been shown to distinguish subjects with dementia of the Alzheimer type (DAT) from nondemented controls. In this study, we obtained magnetic resonance scans in 18 subjects with very mild DAT (CDR 0.5) and 26 age-matched nondemented controls (CDR 0) 2 years apart. Large-deformation high-dimensional brain mapping was used to quantify and compare changes in hippocampal shape as well as volume in the two groups of subjects. Hippocampal volume loss over time was significantly greater in the CDR 0.5 subjects (left = 8.3%, right = 10.2%) than in the CDR 0 subjects (left = 4.0%, right = 5.5%) (ANOVA, F = 7.81, P = 0.0078). We used singular-value decomposition and logistic regression models to quantify hippocampal shape change across time within individuals, and this shape change in the CDR 0.5 and CDR 0 subjects was found to be significantly different (Wilks's lambda, P = 0.014). Further, at baseline, CDR 0.5 subjects, in comparison to CDR 0 subjects, showed inward deformation over 38% of the hippocampal surface; after 2 years this difference grew to 47%. Also, within the CDR 0 subjects, shape change between baseline and follow-up was largely confined to the head of the hippocampus and subiculum, while in the CDR 0.5 subjects, shape change involved the lateral body of the hippocampus as well as the head region and subiculum. These results suggest that different patterns of hippocampal shape change in time as well as different rates of hippocampal volume loss distinguish very mild DAT from healthy aging.     

海马体积对糖尿病认知功能障碍的诊断价值

目的 探讨海马体积对糖尿病认知功能障碍诊断价值。 方法 选择糖尿病合并认知功能障碍（DM+MCI）组20例、病例对照组（DM组）20例、空白对照组（CON组）25例,采用蒙特利尔认知评估（MoCA）量表测评各组认知功能,行磁共振海马成像。 结果 DM+MCI组年龄、空腹血糖、糖化血红蛋白、甘油三酯、总胆固醇、MOCA评分高于DM组及CON组（P<0.05）。DM+MCI组双侧海马的体积明显变小,与MOCA评分具有相关性。左侧海马体积诊断糖尿病认知功能障碍的ROC曲线下面积为0.793（P<0.05）。在最优截断点时,左侧海马体积为2.845 cm3时诊断糖尿病认知功能障碍的灵敏度为95%,特异度为65%,阳性预测值为65%,阴性预测值为35%。右侧海马体积诊断糖尿病认知功能障碍的ROC曲线下面积为0.817（P<0.05）。在最优截断点时,左侧海马体积为2.875 cm3时诊断糖尿病认知功能障碍的灵敏度为90%,特异度为65%,阳性预测值为65%,阴性预测值为35%。 结论 糖尿病认知功能障碍患者海马体积明显变小,其对糖尿病认知功能障碍的诊断有一定临床价值。       

Parahippocampal activation evoked by masked traumatic images in posttraumatic stress disorder: a functional MRI study

Posttraumatic stress disorder (PTSD) has been widely studied, but its neural mechanism is still unclear. The purpose of this study is to identify dysfunctional areas in PTSD throughout the whole brain to help to elucidate the neural mechanisms of PTSD. Sixteen patients with PTSD and sixteen healthy controls participated in this study. Traumatic images under perceptual threshold including scenes of earthquakes, traffic accidents, ambulances, emergency rooms, and crimes were presented to the participants, and brain activation was measured using functional MRI. Functional brain images of both groups were evaluated with random effect analysis for the whole brain. In the control group, activation in the ventral frontoparietal areas correlated significantly with presentation of the masked traumatic stimuli. In the PTSD group, activation was not observed in these areas, but significant activation correlated with the masked traumatic stimuli in the parahippocampal region including the left parahippocampal gyrus and tail of the left hippocampus. These results suggest that in PTSD patients activation in the ventral frontoparietal network associated with visual attention processing is attenuated, while the left hippocampal area associated with episodic and autobiographical memory is abnormally easily activated. This pattern of activation corresponds well to the clinical characteristics of PTSD, in which even slight traumatic stimuli tend to induce intrusive recollection or flashbacks, despite a general decrease in attention and ability to concentrate.     

Patterns of altered cortical perfusion and diminished subcortical integrity in posttraumatic stress disorder: An MRI study

Posttraumatic stress disorder (PTSD) accounts for a substantial proportion of casualties among surviving soldiers of the Iraq and Afghanistan wars. Currently, the assessment of PTSD is based exclusively on symptoms, making it difficult to obtain an accurate diagnosis. This study aimed to find potential imaging markers for PTSD using structural, perfusion, and diffusion magnetic resonance imaging (MRI) together. Seventeen male veterans with PTSD (45 ± 14 years old) and 15 age-matched male veterans without PTSD had measurements of regional cerebral blood flow (rCBF) using arterial spin labeling (ASL) perfusion MRI. A slightly larger group had also measurements of white matter integrity using diffusion tensor imaging (DTI) with computations of regional fractional anisotropy (FA). The same subjects also had structural MRI of the hippocampal subfields as reported recently (W. Zhen et al. Arch Gen Psych 2010;67(3):296–303). On ASL-MRI, subjects with PTSD had increased rCBF in primarily right parietal and superior temporal cortices. On DTI, subjects with PTSD had FA reduction in white matter regions of the prefrontal lobe, including areas near the anterior cingulate cortex and prefrontal cortex as well as in the posterior angular gyrus. In conclusion, PTSD is associated with a systematic pattern of physiological and structural abnormalities in predominantly frontal lobe and limbic brain regions. Structural, perfusion, and diffusion MRI together may provide a signature for a PTSD marker.     

抑郁症患者边缘系统异常的MRI和MRS分析

目的探讨抑郁症患者海马及杏仁核容积改变特点及海马的1HMRS表现.方法探讨22例抑郁症患者及13例健康志愿者两侧海马及杏仁核容积及海马的1HMRS表现.结果抑郁症患者及志愿者均显示两侧海马容积不对称(左侧小于右侧);抑郁症患者两侧海马容积比志愿者有明显减小,杏仁核容积明显不对称(右侧小于左侧);抑郁症患者海马容积缩小与病程缺乏相关性.双侧海马NAA/Cr低于对照组,差异有显著性(P＜0.05).结论海马及杏仁核容积异常和神经化学的改变可能构成抑郁症的神经生物学基础,也说明边缘系统在抑郁症的发病机制中起着重要作用.     

Functional implications of hippocampal volume and diffusivity in mild cognitive impairment

Hippocampal atrophy has been related to mild cognitive impairment (MCI) and early Alzheimer disease (AD), but the diagnostic significance of cross-sectionally determined hippocampal volumes is still ambiguous. Diffusion-Tensor-Imaging (DTI) in MCI patients revealed an association of microstructural changes in hippocampal areas with verbal memory decline. MRI volumetry and DTI were combined to investigate 18 MCI patients attending a memory clinic, and 18 carefully age- and gender-matched healthy controls. Neuropsychological testing, high resolution T1-weighted volume MRI scans, and DTI scans with regions-of-interest in hippocampal areas were applied. Left hippocampal volume was significantly lower (-11%, P = 0.02) in MCI patients than in control subjects. No significant differences were found for the right hippocampus (-4%). Mean diffusivity (MD) was significantly elevated in MCI patients vs. controls in left (+10%, P = 0.002) and right hippocampal areas (+13%, P = 0.02). Hippocampal volume and MD values were not significantly correlated. Combining left hippocampal volume and MD measures showed that lower left hippocampal volumes were associated with poor verbal memory performance particularly when co-occurring with high MD values. No comparable associations could be found regarding the right hippocampal formation and with respect to non-verbal memory function. The results demonstrate that microstructural abnormalities as revealed by DTI are very sensitive early indicators of hippocampal dysfunction. The combination of macro- and microstructural parameters in hippocampal areas could be promising in early detection of neurodegenerative processes.     

磁共振质子波谱无创性分析活体情况下阿尔茨海默 病人脑组织生化代谢改变

目的用磁共振质子波谱(MRS)的方法研究Alzheimer病(Alzheimerdisease,AD)内侧颞叶代谢的改变,试图为临床诊提供客观依据。方法对15例AD病人和15例正常老年人的内侧颞叶进行磁共振质子波谱(MRS)(采用STEAM序列)采集。并对代谢产物的变化与临床简易精神测量评分(MMSE)之间和与海马结构体积测量值之间进行相关性分析。结果AD病人NAA/Cr的降低与MMSE评分和海马体积呈正相关,mI/Cr的升高与MMSE评分和海马体积改变呈负相关。结论MRS能无创性检查AD脑部的代谢变化,1H-MRS所显示的AD的NAA降低和mI升高能提高中早期AD的诊断正确率。     

磁共振特征性追踪技术对肥厚型心肌病心肌应变的初步研究

目的采用心脏磁共振特征性追踪(cardiovascular magnetic resonance feature tracking,CMR-FT)技术对肥厚型心肌病患者的心功能及心肌节段应变进行分析,探讨CMR-FT对肥厚性心肌病患者早期运动异常检测的可行性。材料与方法对17例肥厚型心肌病患者及14名健康志愿者进行3.0 T SSFP电影序列扫描,使用CVI软件检测心功能,并对48个肥厚的心肌节段及健康志愿者中42个正常心肌节段进行特征性追踪(feature tracking,FT)后处理。结果肥厚型心肌病患者与健康志愿者左心功能参数(左心室舒张末期容积、左心室收缩末期容积及左心室射血分数)的差异无统计学意义(P均0.05),肥厚的心肌节段的圆周应变、长轴应变及峰值收缩期圆周应变、峰值收缩期长轴应变均低于正常的心肌节段[(-5.26±2.70)%vs(-11.68±2.06)%,(-7.92±5.07)%vs(-13.93±3.89)%,(-10.44±5.46)%vs(-18.43±2.99)%,(-12.29±8.17)%vs(-20.26±2.93)%,P均0.05]。结论对于心功能正常的肥厚性心肌病患者,CMR-FT技术能够早期检测出肥厚患者肥厚心肌节段应变的变化,提示心肌应变量的改变能够比左心室功能参数更早地发现心肌收缩功能异常。     

Is there a negative correlation between explicit memory and hippocampal volume?

The aim of this research was to study the relationship between explicit memory and hippocampal volume. Seventy healthy adults were administered one implicit memory test and one explicit memory (EM) test and underwent magnetic resonance imaging. The major finding was a negative correlation between the EM test and the right hippocampus/brain volume ratio (t = -0.25, P = 0.03) and the left hippocampus/brain volume ratio (t = -0.27, P = 0.02). This finding is not consistent with pathologic findings, which tend to show a relationship between decrease in memory performance and hippocampal atrophy. This discrepancy is discussed.