磁共振扩散张量成像在缺血缺氧脑病患儿中的临床应用

目的探讨磁共振扩散张量成像(DTI)在缺血缺氧脑病患儿中的应用价值。方法前瞻性纳入2016-12—2018-12于河南中医药大学第一附属医院行MRI头颅平扫及DTI检查的年龄2岁患儿40例,所有患儿在围生期均有缺氧缺血脑病史,根据最终随访结果分为脑瘫组及非脑瘫组各20例。测量双侧大脑脚、内囊前肢、内囊膝部、内囊后肢、半卵圆中心、皮质脊髓束、下纵束、丘脑后辐射、额叶白质、顶叶白质、胼胝体膝部、胼胝体体部及胼胝体压部的FA值。结果 2组间双侧大脑脚、内囊后肢、半卵圆中心、皮质脊髓束、下纵束、丘脑后辐射、顶叶白质、胼胝体膝部、胼胝体体部、胼胝体压部FA值差异均有统计学意义(P0.05),而双侧内囊前肢、内囊膝部、额叶白质FA值差异无统计学意义(P0.05)。结论 DTI可以定量评估缺血缺氧脑病患儿的损伤程度,有助于早期评估病情及预测预后。     

儿童孤独症的脑扩散张量成像研究

目的 研究孤独症儿童脑扩散张量成像的异常.方法 对24例孤独症儿童(孤独症组)和10名正常儿童(正常对照组)进行脑扩散张量成像扫描,测量并比较两组的双侧胼胝体膝部、压部和双侧内囊后肢表观扩散系数(ADC值)和各向异性分数(FA值),分析孤独症儿童各被检测部位ADC值、FA值与孤独症治疗评估量表(ATEC)得分的相关性.结果 (1)孤独症组双侧内囊后肢[左右侧分别为(6.8±0.3)×10-9 mm2/s和(6.7±0.4)×10-9 mm2/s]、左侧胼胝体膝部[(8.0±0.5)×10-9 mm2/s]ADC值高于对照组[分别为(6.6±0.2)×10-9 mm2/s,(6.6±0.4)×10-9 mm2/s,(7.4±0.5)×10-9 mm2/s;P＜0.05～0.01];孤独症组右侧胼胝体压部(0.73±0.14)FA值低于正常对照组(0.84±0.07;P＜0.05),孤独症组右侧胼胝体膝部(0.75±0.07)FA值高于正常对照组(0.68±0.17;P＜0.05).(2)孤独症组右侧胼胝体压部ADC值与ATEC健康/行为评分呈正相关(r=0.490),右侧胼胝体压部FA值与ATEC说话/语言评分呈负相关(r=-0.453),右胼胝体膝部FA值与社交评分呈正相关(r=0.427),均P＜0.05.(3)孤独症组内囊后肢、胼胝体膝部FA值左右侧的差异有统计学意义(P＜0.05).结论 孤独症儿童胼胝体神经纤维连接存在异常.     

MRI正常额叶癫(癎)患者的MR扩散张量成像研究

目的应用MR扩散张量成像（DTI）技术探讨MRI正常的额叶癫痢患者与运动相关白质是否存在隐匿性病变。方法对临床确诊的16例MRI正常的额叶癫痫患者发作间期和30例健康志愿者行常规MRI和DTI检查,定量测量额叶皮层下白质、胼胝体膝部和压部、内囊前肢和后肢及外囊的平均扩散系数（DCavg）和部分各向异性（FA）值,并进行统计学分析。结果MRI正常的额叶癫痴患者额叶皮层下白质、胼胝体膝部区域的DCavg值显著高于正常人（P〈0．01）,皮层下白质的FA值显著低于正常人（P〈0．01）,胼胝体膝部的FA与正常人无差异。结论MRI正常的额叶癫痫患者存在额叶隐匿性损害DTI为发现致痢灶提供理论依据,具有临床应用价值。     

磁共振扩散张量成像对轻型颅脑损伤的临床诊断价值

目的探讨磁共振(MR)扩散张量成像(DTI)在轻型颅脑损伤患者诊断中的价值。方法选择轻型颅脑损伤患者(病例组)和健康志愿者(对照组)各40例,病例组再分为有/无认知功能障碍亚组(分别为22例和18例),分别行MR DTI扫描,对病例组进行里蒙德脑震荡后综合征问卷(RPQ)评分,比较两组额叶白质、颞叶白质、内囊、胼胝体的部分异向性(FA)和表观扩散系数(ADC),并比较病例组有和无认知功能障碍患者的上述各项指标。结果病例组和对照组MRI常规扫描和DTI扫描均未见异常信号;病例组和对照组两侧额叶白质、颞叶白质、内囊、胼胝体膝部、压部的ADC值差异均无统计学意义(P0.05);病例组两侧额叶白质、颞叶白质、内囊及胼胝体压部的FA值均低于对照组(P0.05),RPQ评分高于对照组;病例组有认知功能障碍亚组两侧额叶、颞叶FA值低于无认知功能障碍亚组(P0.05)。结论轻型颅脑损伤患者存在脑组织损伤,FA值是判断脑组织损伤的敏感指标,DTI检查为轻型颅脑损伤的临床诊断提供了有力的依据。     

轻度创伤性脑损伤后脑组织微环境变化:多模态磁共振成像研究

目的探讨弥散张量成像(DTI)联合磁共振波谱(MRS)及磁敏感加权成像(SWI)的功能磁共振成像方法,在评估轻度创伤性脑损伤(mTBI)脑组织代谢及微结构变化的应用价值,为临床制定相应的治疗方案提供影像学参考。方法纳入21例mTBI患者和16例健康志愿者,mTBI患者在伤后4～72 h内接受T1WI、T2WI、FLAIR、DTI、MRS及SWI序列扫描,通过各序列图像及参数值评估mTBI患者伤侧脑组织和对照组内囊前肢、内囊后肢、胼胝体膝部、胼胝体压部、扣带回、半卵圆中心、额叶白质及视辐射的差异。结果两组FA值比较,仅胼胝体压部差异有统计学意义(P0.01)。mTBI组胼胝体膝部NAA/Cr值低于对照组,差异有统计学意义(P0.01)。mTBI组内囊后肢和胼胝体膝部Cho/Cr值均高于对照组,差异均有统计学意义(P0.05或0.01)。结论 FA值及NAA、Cho、Cr值能测定mTBI后脑组织水分子扩散及代谢情况,DTI联合MRS及SWI可以作为一项客观指标,定量评估mTBI患者的病情及预后。     

皮质下缺血性血管性痴呆患者脑白质损害的磁共振弥散张量成像研究

目的:应用磁共振弥散张量成像技术(DTI)观察皮质下缺血性血管性痴呆(SIVD)患者脑白质损害程度,探讨DTI对SIVD白质损害的评估及与阿尔茨海默病(AD)鉴别诊断价值。方法:研究对象分为3组,分别是健康老年人(NC)、皮质下缺血性血管性痴呆(SIVD)患者、AD患者,每组各20例。行常规MR I和DTI扫描后,测定相同感兴趣区(RO I)的各向异性分数(FA)值和表观扩散系数(ADC)值进行比较。结果:SIVD组下额枕束、胼胝体膝部、胼胝体压部、上纵束等部位FA值下降,ADC值升高,与NC、AD组比较差异有统计学意义(P<0.05)。与NC组比较,AD组前额叶、颞叶、海马、下额枕束、胼胝体膝部和扣带束等部位FA值降低,颞叶、海马等部位ADC值升高,两组差异具有显著性(P<0.05);结论:DTI可以用来评估痴呆患者白质损害的程度,SIVD患者以下额枕束、胼胝体膝部、胼胝体压部、上纵束等部位受累为主,可作为与AD鉴别的客观指标。     

左侧颞叶癫痫患者颞叶以外白质的磁共振扩散张量成像分析

目的 探讨左侧颞叶癫痫患者颞叶以外白质磁共振扩散张量成像(DTI)的影像学特征。方法 选取2020年12月至2022年5月贵州医科大学第二附属医院收治的30例左侧颞叶癫痫患者作为观察组,并选取同期30例正常志愿者作为对照组,2组患者均进行DTI扫描,收集丘脑、内囊、外囊、放射冠及半卵圆中心白质区域的平均扩散率(MD)和部分各向异性(FA)值,分析颞叶以外白质区域MD和FA值与癫痫严重程度的相关性。结果 观察组患者丘脑、内囊、外囊、放射冠及半卵圆中心区域MD值高于对照组(P<0.05),而FA值低于对照组(P<0.05)。癫痫患者颞叶以外白质区域MD值与癫痫严重程度呈正相关(P<0.05),FA值呈负相关(P<0.05)。结论 DTI各参数能反映颞叶癫痫患者非病灶区纤维束的变化,这些区域神经纤维束的变化可能与癫痫的严重程度密切相关。     

脊髓小脑共济失调2型患者的磁共振弥散张量成像特点及部分相关性分析

目的研究脊髓小脑共济失调2型(SCA2)患者磁共振弥散张量成像(DTI)特点及其与病程、CAG重复序列的相关性。方法选择10例经基因检测证实为SCA2的患者作为病例组,并得出CAG重复次数,10例健康志愿者作为对照组,分别进行DTI检查,测量感兴趣部位的ADC值和FA值,并进行两样本参数的t检验比较两组间的不同。分析有统计学意义的部位(阳性部位)的ADC值和FA值与病程及CAG重复次数的相关性;分析CAG重复序列与发病年龄的相关性。结果 (1)病例组的延髓、小脑白质、小脑中脚、脑桥、黑质、壳核、苍白球、内囊前肢8个部位的ADC值显著高于正常对照组;延髓、小脑白质、小脑中脚、脑桥、壳核、内囊前肢、内囊膝部、内囊后肢、胼胝体膝部、胼胝体压部、大脑白质11个部位的FA值显著低于正常对照组。(2)CAG重复序列与阳性部位的ADC值无相关性,与小脑白质、壳核的FA值成负相关,与其余阳性部位的FA值无相关性。CAG重复序列与发病年龄成明显负相关。结论 (1)通过对脑组织中的某些部位进行ADC值、FA值测量能够有效的辅助SCA2诊断,其中以延髓、小脑中脚、脑桥处的测量最为准确。(2)CAG重复序列与发病年龄明显相关。     

三叉神经痛的磁共振扩散张量成像研究

目的 研究血管压迫三叉神经桥池段的扩散张量成像(DTI)表现及临床应用价值.方法 对60例经手术证实的因责任血管压迫引起三叉神经痛(TN)患者(TN组)和50例健康志愿者(对照组)行常规MRI和横轴面DTI成像,测量其表观扩散系数(ADC)值、部分各向异性分数(FA)值. 结果 对照组的三叉神经的ADC值为(1.76±0.98)×10-3 mm2/s,FA值为0.40±0.18,左侧与右侧三叉神经桥池段的ADC值和FA值差异均无统计学意义(P>0.05);对照组与TN组中B组(轻度压迫组)、C(重度压迫组)、D组(受压变形并萎缩)3组比较,ADC、FA值差异均存在统计学意义(P均<0.05);压迫部位ADC值增高28例,不变4例,平均ADC值明显高于对照组(P<0.05);压迫部位FA值下降15例.不变11例,增高5例,平均FA值明显低于对照组(P<0.05). 结论 DTI对判断血管压迫三叉神经有一定价值,三叉神经压迫程度越大,ADC值越高,FA值越低.     

精神分裂症首次发病患者的脑扩散张量成像研究

目的 利用磁共振扩散张量成像(DTI)技术研究未经药物治疗的精神分裂症首次发病(以下简称首发)患者主要脑区白质纤维束的异常.方法 选取26例首发精神分裂症患者(患者组)和20名健康志愿者(对照组)行脑DTI扫描(两组均为右利手),测量胼胝体膝部、压部、双侧额叶白质、扣带束前部及海马头的部分各向异性(FA)值.结果 (1)对照组左侧扣带束FA值(0.428±0.067)大于右侧(0.375±0.079;P＜0.05).(2)患者组两侧相对应感兴趣区FA值差异均无统计学意义(P＞0.05).(3)患者组左右侧胼胝体压部FA值(均为0.734±0.085)、左右侧扣带束前部FA值(0.300±0.068和0.306 4±0.062)均低于对照组(0.785±0.045,0.428±0.067,0.375±0.079;均P＜0.05).结论 首发精神分裂症患者存在双侧扣带束、胼胝体压部白质纤维束的受损,支持脑内连接异常假说.     

胼胝体和扣带回弥散张量成像改变对皮质下缺血性血管性痴呆患者认知功能障碍的影响

目的应用磁共振弥散张量成像(DTI)技术,探讨皮质下缺血性血管性痴呆(SIVD)患者胼胝体和扣带回弥散张量参数改变与认知功能的关系。方法对60例SIVD患者和40例年龄匹配的非痴呆对照者,采用测定感兴趣区弥散张量参数的方法,比较其纤维束完整性差异及与MMSE的关系。结果 (1)与对照组比较,SIVD组胼胝体膝部、双侧扣带回的FA值显著下降及ADC值显著升高,而胼胝体压部的FA值和ADC值无显著性差异。(2)胼胝体膝部、双侧扣带回的FA值与MMSE评分呈明显正相关。结论胼胝体和扣带回弥散张量改变有助于SIVD患者认知功能障碍的早期预测。     

创伤后应激障碍患者扣带束及胼胝体纤维束FA值的初步研究

目的探讨创伤后应激障碍患者(PTSD)是否存在连合纤维束胼胝体及联络纤维扣带纤维束的超微结构异常。方法1.5T的MR成像仪下对12例PTSD患者及12名正常对照进行磁共振弥散张量成像(DTI),测量受试者胼胝体膝部、体部、压部、及双侧扣带水平部、后部等感兴趣区内主要白质纤维束的各向异性分数(FA)值,并进行组间比较。结果患者组双侧(左侧、右侧)扣带束水平部、胼胝体压部的FA值较对照组明显降低,差异均有统计学意义(t分别为3.26、-4.13、2.84,P均小于0.05)。结论PTSD患者的边缘系统纤维束可能存在结构异常。     

轻度认知功能障碍与脑白质弥散张量成像的相关性研究

目的通过磁共振弥散张量成像研究不同区域脑白质损害与轻度认知功能(MCI)的关系。方法纳入2015年7月至2016年2月我院的住院患者56例为研究对象,其中MCI组34例,认知功能正常组22例。所有研究对象进行一般情况检查,完成神经心理学量表检测。通过头颅磁共振弥散张量成像(DTI)检查对不同脑区白质纤维进行部分各向异性(FA)值测量。结果 MCI组患者与认知功能正常组相比,右侧额叶FA值(0.335±0.068)、左侧颞叶白质FA值(0.391±0.032)及胼胝体膝部FA值(0.658±0.053)降低,差异具有统计学意义(P0.05)。将上述FA值和MMSE、Mo CA量表中各认知域进行典型相关分析,结果显示右侧额叶白质FA值与注意与计算力呈正相关,左侧颞叶白质和胼胝体膝部FA值与记忆力呈正相关(P0.05)。结论 MCI患者注意与计算力的障碍可能与右侧额叶白质损害有关,而左侧颞叶白质及胼胝体膝部白质的损害可能导致早期的记忆障碍。DTI可能成为超早期识别与诊断MCI的新方法。     

Quantification of age- and gender-related changes in diffusion tensor imaging indices in deep grey matter of the normal human brain

This study aimed to demonstrate age-related and gender-related changes in diffusion tensor imaging (DTI) indices of deep grey matter (GM) nuclei of the normal human brain. DTI was performed on 142 subjects (age: 10-52 years). Regions of interest were placed on the caudate nucleus (CN), putamen, globus pallidus, frontal white matter (WM), occipital WM, anterior and posterior limb of internal capsule, genu of the corpus callosum and splenium in all participants. The quadratic regression model was used to describe age-related and gender-related changes in DTI indices for GM and WM. We observed increased fractional anisotropy (FA) values with age up to adulthood in GM, and a rise up to the third decade of life followed by a decrease in FA for WM. We observed higher FA values in males compared to females in CN and all WM regions. Decreased mean diffusivity with age was observed in GM and WM irrespective of gender. This normative data may be valuable in the diagnosis of neurodegenerative diseases.     

Assessing sequence and relationship of regional maturation in corpus callosum and internal capsule in preterm and term newborns by diffusion-tensor imaging

BackgroundDiffusion-tensor imaging (DTI) can be used to investigate water diffusion in living tissue.ObjectiveTo investigate sequence and relationship of regional maturation in corpus callosum (CC) and internal capsule (IC) in preterm and term.MethodsDTI was performed on 11 preterm infants at less than 37 weeks of corrected gestational age (group I), 21 preterm infants at equivalent-term (group II), 11 term infants during neonatal period (group III). Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in: anterior limb of IC (ALIC), posterior limb of IC (PLIC), genu and splenium of CC.ResultsFA in splenium was more than that in other regions except genu of group I. Differences of FA between genu and PLIC were significant only in group III. ADC in genu was more than that in other regions but in splenium of groups I and II. Differences of ADC between splenium and ALIC were insignificant except group II. Higher FA and lower ADC in PLIC were gotten compared with those in ALIC. Correlations of FA and of ADC existed in CC and IC.ConclusionMaturation sequence was splenium followed by genu, then by PLIC and last by ALIC in term at neonatal period. Genu's maturation in preterm at equivalent-term was hindered. Regional maturation's correlations existed in CC and IC.     

胼胝体网络连接性与脑白质疏松认知功能损害的相关性

目的 通过弥散张量成像（diffusion tensor imaging,DTI）研究脑白质疏松（leukoaraiosis,LA）患者胼 胝体网络连接性改变,并探讨其与认知功能损害的关系。 方法 本研究为前瞻性单中心研究。纳入30例法泽卡斯量表（Fazekas scale）评分为2～3级的LA患 者及20例头部磁共振成像正常的对照组。依据是否存在认知功能损害将LA组再分为认知正常与轻 度认知功能损害2个亚组。所有被研究对象均进行脑血管危险因素登记、血液生化检查、认知功能 评估筛查及3.0T头部磁共振成像检查及DTI检查。认知评估采用中文版蒙特利尔认知评估（Montreal Cognitive Assessment,MoCA）量表及简易智力状况检查（Mini-mental State Examination,MMSE）量表。使 用PANDA软件处理DTI数据,提取胼胝体膝部、体部及压部的部分各向异性（fractional anisotropy,FA） 和平均扩散系数（mean diffusivity,MD）数值。采用Pearson相关分析研究DTI数据变化与认知功能损害 的关系。 结果 LA组与对照组的性别、年龄、受教育情况、脑血管病常规危险因素及血生化之间差异无 显著性,P >0.05。LA组的MMSE及MoCA分值低于对照组,P值分别为0.002和0.008。LA组胝体膝部 （P =0.000）、体部（P =0.000）、压部（P =0.026）3个部位的FA值均低于对照组,而MD值高于对照组,P 值分别为0.013、0.006及0.007。LA组MMSE及MoCA分值降低与胼胝体膝部、体部、压部的FA下降均成 正相关,但相关系数从膝部（r =0.78）到压部（r =0.41）呈现逐渐递减趋势。 结论 LA存在胼胝体网络连接性改变,胼胝体FA下降与认知功能损害密切相关。     

Extratemporal white matter abnormalities in mesial temporal lobe epilepsy demonstrated with diffusion tensor imaging

PURPOSE: Recent studies have demonstrated bilateral white matter abnormalities in temporal lobe epilepsy (TLE) patients with unilateral mesial temporal sclerosis (MTS). The purpose of this project was to determine whether abnormalities of water diffusion are seen in extratemporal white matter of patients with TLE and pathologically confirmed MTS and to determine whether these findings are associated with worse surgical outcome. METHODS: Eleven patients with TLE and unilateral MTS confirmed in surgical specimens and 14 controls were studied by using cerebrospinal fluid-suppressed diffusion tensor imaging (DTI) and T2 relaxometry. RESULTS: Hippocampal T2 signal for patients was significantly elevated both ipsilateral (p<0.001) and contralateral (p=0.006) to MTS. DTI demonstrated reduced fractional anisotropy of the genu of the corpus callosum (p=0.003) and external capsule (p=0.02) and elevated mean diffusivity of the genu (p=0.005), splenium (p=0.03), and external capsule (p<0.001). For both the genu and external capsule, parallel diffusion of patients was not different from that of controls (genu, p=0.81; external capsule, p=0.45), whereas perpendicular diffusion was elevated (genu, p=0.001; external capsule, p<0.001). With mean postsurgical follow-up of 18.5 months, eight of 11 patients were entirely seizure free and the remaining three had all experienced a worthwhile reduction in seizure frequency. CONCLUSIONS: Our findings suggest that although patients with TLE and MTS have extensive bilateral and extratemporal pathology, these findings may not be associated with a worse postsurgical outcome.     

A comparative diffusion tensor imaging study of corpus callosum subregion integrity in bipolar disorder and schizophrenia

Structural magnetic resonance imaging (MRI) studies have provided evidence for corpus callosum (CC) white matter abnormalities in bipolar disorder (BD) and schizophrenia (SZ). These findings include alterations in shape, volume, white matter intensity and structural integrity compared to healthy control populations. Although CC alterations are implicated in both SZ and BD, no study of which we are aware has investigated callosal subregion differences between these two patient populations. We used diffusion tensor imaging (DTI) to assess CC integrity in patients with BD (n=16), SZ (n=19) and healthy controls (HC) (n=24). Fractional anisotropy (FA) of CC subregions was measured using region of interest (ROI) analysis and compared in the three groups. Significant group differences of FA values were revealed in five CC subregions, including the anterior genu, middle genu, posterior genu, posterior body and anterior splenium. FA values of the same subregions were significantly reduced in patients with SZ compared with HC. FA values were also significantly reduced in patients with BD compared to the HC group in the same subregions, excepting the middle genu. No significant difference was found between patient groups in any region. Most of the alterations in CC subregions were present in both the BD and SZ groups. These results imply an overlap in potential pathology, possibly relating to risk factors common to both disorders. The one region that differed between patient groups, the middle genu area, may serve as an illness marker and is perhaps involved in the different cognitive impairments observed in BD and SZ.     

A voxel-based diffusion tensor imaging study of temporal white matter in patients with schizophrenia

Diffusion tensor imaging (DTI) is a relatively new technique used to detect changes in the anisotropic diffusion of white matter. The study of the disruption of brain connectivity may increase our understanding of cognitive deficits associated with schizophrenia. Here we analysed DTI data in 25 patients with DSM-IV schizophrenia and 24 healthy controls. Two complementary measures, fractional anisotropy (FA) and the apparent diffusion coefficient (ADC), were considered and analysed using voxel-based morphometry. Declarative memory functions were also investigated and their associations with DTI data were analysed. FA was significantly reduced, and the ADC increased in the left sub-gyral white matter of the temporal lobe, which involves the posterior part of the fornix. In the schizophrenic group, females had lower FA than males in the genu of the corpus callosum. Memory functions correlate with FA values. These data provide further evidence for the disruption of white matter connectivity in the left medial temporal lobe, and for its contribution to the declarative memory deficit in schizophrenia.