DWI成像预测低血糖脑病的结局

目的 探讨低血糖脑病DWI成像和预后的关系.方法 回顾性分析4例严重低血糖患者的临床和磁共振资料. 结果 低血糖脑损害有高度的区域选择性,主要侵犯海马、大脑皮质、基底节区和胼胝体.MRI有特异性,表现为等或稍长T1、长T2异常信号,DWI呈高信号,部分病变可逆.结论 低血糖脑损害有很强的区域选择性.DWI像发现病变更早更敏感,对预后很有帮助.弥漫侵犯大脑皮质和(或)基底节区患者多预后差.     

可逆性胼胝体压部病变综合征一例

目的探讨可逆性胼胝体压部病变综合征的临床特点、磁共振(MRI)影像学特征、治疗方法及预后。方法分析1例可逆性胼胝体压部病变综合征临床资料并结合相关资料对此例胼胝体压部局灶性孤立病变进行分析。结果患者胼胝体压部椭圆形长T1、长T2信号,Flair及DWI高信号影,经抗病毒及对症处理后发病第14天病灶消失。结论可逆性胼胝体压部病变综合征临床特征以MRI发现胼胝体压部孤立病灶为特点,病因、发病机制尚不明确,有一定自愈性。     

2例可逆性脑病综合征的临床及影像学对比分析

目的 对比可逆性后部白质脑病综合征与可逆性胼胝体压部综合征的临床及影像学特点,以加深对这两种病的认识。方法 对比分析本院收治的可逆性后部白质脑病综合征与可逆性胼胝体压部综合征的临床表现及影像学特点。结果 该例可逆性后部白质脑病综合征的诱因为严重感染,主要临床表现为癫痫发作; 神经影像学以双侧大脑半球后部可逆性白质异常病变为特征。该例可逆性胼胝体压部综合征的诱因为低血糖,主要临床表现为精神症状及言语行为异常; 神经影像学以胼胝体压部的孤立性异常信号和病灶的可逆性消失为特征。结论 可逆性脑病综合征的诱因复杂、临床表现多样,有类似的病理基础,核磁共振成像均有特异性改变,且病灶均为可逆性改变,均为预后良好的可逆性脑病综合征,尽早正确治疗对减轻神经功能损害至关重要。     

可逆性胼胝体压部病变综合征的影像表现

目的：探讨可逆性胼胝体压部病变综合征的临床及影像特点。方法对我院收治的9例可逆性胼胝体压部病变综合征患者的临床及影像资料进行回顾性分析。结果9例患者中婴幼儿3例,儿童1例,成人5例;2例婴幼儿及1例儿童有发热等感染病史伴神经症状,1例婴幼儿以缺血缺氧性脑病入院,成人以头痛、发热、昏迷、意识障碍等为主入院,其中伴有癫痫病史2例。头颅MRI显示胼胝体压部类圆形（婴幼儿累及全胼胝体压部）稍长T1稍长T2信号,FLAIR序列呈高或稍高信号,DWI呈高信号;其中3例增强扫描未见强化;头颅CT显示欠佳。经对症治疗后,症状缓解,MRI复查示胼胝体压部异常信号消失。结论可逆性胼胝体压部病变综合征的临床无特异性,而M RI表现有一定特征性,可为临床的诊疗及预后提供指导。     

低血糖脑病的临床和神经影像学特点

目的 探讨低血糖脑病(HE)的临床和神经影像学特点.方法 回顾性分析49例HE患者的临床和神经影像学资料.结果 本组HE患者临床表现为意识障碍26例,精神行为异常19例,癫癎发作6例,言语不清、反应迟钝10例,偏瘫和单肢瘫5例,去脑强直发作3例.23例行头颅CT检查,除10例见有脑梗死和脑萎缩外余无异常改变.13例行MRI检查,7例异常,其中显示弥漫性皮质和海马受累者3例(2例同时波及基底节区,1例仅累及右侧大脑皮质,MRS示病变区乳酸峰无明显异常),胼胝体压部受损2例(1例患者10 d后病变恢复,1例伴内囊后肢受累),壳核和放射冠区白质受累各1例,表现为等或稍长T1、长T2异常信号,DWI呈高信号伴表观扩散系数(ADC)降低.结论 HE的临床表现多不典型;MRI有高度特异性,DWI序列对病变更敏感.     

胼胝体病变-肝豆状核变性的少见脑部影像学表现

目的研究肝豆状核变性患者胼胝体病变及其临床价值。方法收集3例肝豆状核变性患者的临床及影像资料,参照2001年第八届莱比锡肝豆状核变性国际会议制定的诊断评分系统评分。利用磁共振成像(MRI)技术检查胼胝体压部病变。结果 3例患者均存在胼胝体压部病变,但均无胼胝体病变所致的失连接综合征表现。头颅MRI技术提示3例患者胼胝体病变主要为长T2异常信号、FLAIR像稍高信号,其中1例DWI呈高信号。出现胼胝体病变的3例肝豆状核变性患者均病情较重、脑部损伤弥漫(尾状核、壳核、苍白球、丘脑、中脑及桥脑)。结论胼胝体病变为肝豆状核变性患者少见的影像学表现,若在有典型基底节病变的同时还伴有胼胝体病变则高度支持肝豆状核变性的诊断。胼胝体病变也提示患者病情较重、脑部损伤弥漫,预后相对较差。     

伴有胼胝体压部可逆性病灶的临床症状轻微的脑炎/脑病1例报道并文献复习

目的探讨伴有胼胝体压部可逆性病灶的临床症状轻微的脑炎/脑病的临床特点、治疗及预后、发病机制。方法报道1例伴有胼胝体压部可逆性病灶的临床症状轻微的脑炎患者的诊治过程,总结其临床特征并复习相关文献。结果患者表现为发热、头痛、呕吐等非特异性脑膜炎症状,合并出现抗利尿激素分泌不当导致的低钠血症,头颅MRI检查发现胼胝体压部有可逆性的DWI高信号的孤立病灶,经抗病毒及对症治疗,临床痊愈。结论伴有胼胝体压部可逆性病灶的临床症状轻微的脑炎/脑病以头颅MRI上发现胼胝体压部可逆性病灶为特点,临床症状轻微,容易合并低钠血症,预后良好,病因及发病机制尚不清楚。     

低血糖脑病的临床及脑部磁共振特征

目的探讨低血糖脑病的临床及脑部磁共振特征。方法回顾分析69例低血糖昏迷患者的临床、脑磁共振（MRI）成像资料。结果低血糖昏迷诱因较为复杂,常见的为进食减少、腹泻、上呼吸道感染、降糖药物应用不当等。临床表现复杂多样,除意识障碍外,还可表现为偏瘫、四肢瘫、凝视麻痹等,多数伴有Babinski征。69例患者中有18例出现脑MRIDWI异常高信号病灶,病灶主要累及海马、基底节、大脑皮质以及皮质下白质,多为对称性损害。3个月后随访,不伴有脑部MRI损害的患者预后良好率明显高于伴有脑部MRI损害的患者（94．12％对22．22％;P=0．0011）。伴有脑部MRI损害者有10例患者预后不良,其中9例（90％）发生于皮质受累患者。结论低血糖脑病临床表现不具有特异性,对于昏迷患者,应当考虑到低血糖的可能。降糖药物应用不当为低血糖脑病的主要诱发因素。脑部MRI要优于脑部CT检查,其中DWI序列对于检测低血糖所致的脑部损害有着非常重要的意义。皮质受累者预后不良。     

胼胝体压部可逆性病变的MRI诊断与临床分析

目的探讨胼胝体压部(splenium of the corpus callosum,SCC)可逆性病变的MRI表现及临床特点。方法回顾性分析8例脑MRI表现为单纯胼胝体压部可逆性病变患者的临床和影像学资料。结果 8例患者的SCC可逆性病变均为继发性,原发病分别为脑内感染5例,肝豆状核变性、低血糖脑病及脑外伤各1例。8例患者均急性起病,临床表现为发热、头痛5例,急性意识障碍2例,肌张力增高2例,颈强2例,均符合原发病的临床表现。8例均行脑MRI检查,均表现为T1低或等信号,T2及FLAIR序列高信号,DWI高信号(提示细胞源性水肿),其中4例行增强扫描未见强化。8例患者均于临床症状好转或消失后复查MRI提示病灶消失。结论 SCC可逆性病变在多种疾病中均可出现,无该病变相关的特异性临床表现,MRI表现提示病灶为细胞源性水肿可能。     

轻微型肝性脑病磁共振扩散加权成像和扩散张量成像的定量研究

目的通过磁共振扩散加权成像(DWI)和扩散张量成像(DTI)定量分析轻微型肝性脑病(MHE)患者脑功能的异常改变,探讨DWI和DTI在MHE中的应用价值。方法30例肝硬化患者经神经心理测试评分量表测试后,分为MHE组16例和无MHE单纯肝硬化组14例,同时选取15例健康志愿者为正常对照组。所有受试者均行DWI与DTI扫描,选取脑内8个部位为感兴趣区,计算各部位的表观扩散系数(ADC)值和各向异性分数(FA)值。结果18例肝硬化患者于T1WI图像上可见到双侧内囊、苍白球对称性高信号。额叶、枕叶白质、胼胝体膝部、胼胝体压部、内囊前肢、内囊后肢、尾状核头部由正常组、单纯肝硬化组至MHE组ADC值逐渐增加,且MHE组的ADC值较肝硬化组和正常组增加,差异有统计学意义(P<0.05);胼胝体膝部和压部的FA值由正常组、单纯肝硬化组至MHE组逐渐降低,差异有统计学意义(P<0.05)。结论DWI与DTI联合应用能够预测肝硬化患者MHE的进展程度,具有潜在的临床价值。     

DWI及SWI序列对弥漫性轴索损伤的诊断价值

目的探讨弥散加权（DWI）和磁敏感加权（SWI）序列在脑弥漫性轴索损伤（DAI）中的诊断价值。方法回顾性分析17例经临床和影像证实的急性DAI患者的MRI资料,包括常规T1WI、T2WI、液体衰减反转恢复（FLAIR）序列以及DWI和SWI序列,分别比较各序列对DAI非出血性和出血性病灶的检出数目,并分析其分布特点和信号特征。结果DAI病灶主要分布在白质、皮髓交界区、基底节、胼胝体、脑干及小脑等区域。DWI对非出血性DAI病灶的检出率最高,与其它序列的差异有统计学意义（P〈0．05）。而SWI对出血性DAI病灶的检出率最高,与其它序列的差异也均有统计学意义（P〈0．05）。结论DWI和SWI序列联合应用大大提高DAI病灶的检出率,为临床早期诊断提供更加可靠的影像学依据,应作为MRI检查DAI的常规和首选序列。     

Dynamic changes in magnetic resonance diffusion-weighted and fluid-attenuated images of cerebral fat embolism: a case report]

Cerebral fat embolism (CFE) is serious complication of a long-bone fracture. We reported magnetic resonance (MR) diffusion-weighted (DWI) and fluid attenuated inversion recovery (FLAIR) images in a patient suffered with CFE. A 26-year-old man with a right femoral bone fracture lapsed into a semicoma eight hours later. Eighteen hours after the depressed consciousness, DWI and FLAIR images on MR imaging showed multiple high-intensity spots in corona radiata, basal ganglia, thalamus, corpus callosum, brain stem and cerebellum. Thereby, he was diagnosed as CFE. These multiple lesions were more detectable on FLAIR images than DWI, particularly in posterior fossa. Eight days after the onset, follow-up DWI, FLAIR, and T 2-weighted MR image (T 2 WI) showed most of the lesions disappeared or shrunk. The resolution of the lesions suggests that most of the lesions were brain edema as a result of the unique pathophysiological condition of CFE. The remained lesions were diagnosed as cerebral infarctions. The consciousness of the patient improved alert. Three months later, follow-up MRI showed almost complete resolution of the abnormal intensities. Follow up DWI and FLAIR images observed in the patient indicated that many small lesions occurs throughout the whole brain without a preferential region, and many of the lesions can subside or attenuate in CFE.     

Diffusion-weighted MRI and 99mTc-HMPAO SPECT in delayed relapsing type of carbon monoxide poisoning: evidence of delayed cytotoxic edema

BACKGROUND: Carbon monoxide (CO) is a common cause of poisoning, and its sequelae include a progressive (25%) and a delayed relapsing form (75%). We report the diffusion-weighted MRI (DWI) findings in the delayed relapsing form of CO poisoning and characterize the types of edema. METHODS: From November 1, 2000 to June 1, 2003, 5 consecutive patients (2 men, 3 women, range of age: 54-67 years), who had the delayed relapsing type of CO poisoning, underwent DWI, conventional MRI, MR angiography and SPECT. CO poisoning was diagnosed by the presence of a typical clinical history, an abnormally increased level of serum carboxyhemoglobin and MRI findings. Apparent diffusion coefficient (ADC) values were measured in all of the abnormal lesions with visual inspection of DWI and T(2)-weighted echo-planar imaging. RESULTS: DWI showed high signal intensities in bilateral periventricular white matter, in the splenium of the corpus callosum, in internal capsules, and brainstem showing moderately decreased ADC values. In the globus pallidus, the ADC values were rather increased with low signal intensities on DWI. Brain SPECT showed decreased perfusion in bilateral white matter and some parts of the cerebral cortex, which correlated well with the DWI findings. CONCLUSIONS: We suggest that prominent, symmetric restricted diffusion can occur in periventricular white matter, brainstem, and corpus callosum after the delayed relapsing type of CO poisoning. Delayed cytotoxic edema can occur in this setting, which provides a new guidance for the pathogenesis of CO poisoning and the differential diagnosis of white matter diseases.     

Serial diffusion-weighted MRI and SPECT findings in a Creutzfeldt-Jakob disease patient with V180I mutation

We report serial changes of diffusion-weighted imaging (DWI) and single photon emission computed tomography (SPECT) in a patient with Creutzfeldt-Jakob disease with V180I mutation (CJD180). DWI abnormalities in our patient were more predominantly observed in the left cerebral cortex than left basal ganglia. Hemilateral abnormalities progressed over 5 months to involve the contralateral side with increasing DWI signals. At 6 months, SPECT showed hypoperfusion in the left parietal and frontal lobes and the hypoperfusion region spread to the bilateral basal ganglia, right parietal and frontal lobes. SPECT imaging revealed marked cerebral blood flow reduction, predominantly in the cerebral cortex corresponding to brain areas with high-intensity DWI signals. During the follow-up period of CJD180, DWI was more sensitive than conventional FLAIR and T2-weighted images (T2WI) to detect and monitor the progression of abnormal hyperintense lesions. We suggest that serial DWI and SPECT findings are useful for not only early diagnosis of CJD but also for monitoring disease progression.     

Diffusion-weighted imaging demonstrates transient cytotoxic edema involving the corpus callosum in a patient with diffuse brain injury

Reversible T2 hyperintense signal abnormality in the corpus callosum, although frequently seen after diffuse brain injury, has not been well clarified. With some accumulated evidence, we report a case of diffuse brain injury in a 24-year-old man. Magnetic resonance imaging (MRI) demonstrated T2 hyperintense signals in the trunk and the splenium of the corpus callosum 12 days postinjury. Echo-planar diffusion-weighted imaging was also performed on the same day, which revealed decreased diffusion (hyperintense signals) in the same site and almost the same size as T2 hyperintense signals. T1-weighted images were normal. Neuropsychological examination of the patient did not show callosal syndrome, namely hemialexia, unilateral agraphia and unilateral apraxia. Repeat MRI on day 20 demonstrated a signal decrease of both T2-weighted images and diffusion-weighted images (DWI) in the lesion. Follow-up MRI at 6 months showed complete resolution of the T2 signal abnormalities and of the corresponding decreased diffusion. Considering that diffusion-weighted imaging showed transient decreased diffusion, the lesion in the corpus callosum indicated the existence of cytotoxic edema. Also, transient DWI hyperintensity, namely cytotoxic edema, in the trunk and the splenium of the corpus callosum does not necessarily reveal callosal deficits.     

MRI sequence findings in sporadic Creutzfeldt–Jakob disease

MRI has had an important role in the diagnosis of Creutzfeldt–Jakob disease (CJD). The aim of our study was to compare the efficacy of different MRI sequences among six biopsy-proven patients with sporadic CJD (sCJD) and seven patients with probable sCJD. These 13 patients with CJD aged from 36 years to 75 years (mean age: 55.5 years) were evaluated with T1-weighted, T2-weighted, and fluid-attenuated inversion recovery (FLAIR) MRI and diffusion-weighted imaging (DWI). The characteristic MRI lesion pattern was found to be bilateral, symmetric and hyperintense signal changes in the basal ganglia and cortical regions. Two major lesion patterns were identified in all patients involving the cortex and basal ganglia. No signal abnormality was found in the thalamus. We found lesions in the cortex and basal ganglia in 7/13 patients (54%), isolated cortical involvement in 2/13 patients (15%), and isolated basal ganglia lesions in 4/13 patients (31%). The cortical involvement was widespread (in at least two regions) and usually included the frontal or occipital lobes (9/13, 69%) on DWI. Only one patient showed moderate high-signal intensity in the basal ganglia on T2-weighted MRI. T1-weighted MRI revealed no signal intensity abnormalities. We conclude that high signal changes in the basal ganglia and cerebral cortex on FLAIR and DWI are useful in the diagnosis of sCJD. Isolated cortical involvement on DWI and FLAIR should lead to a suspicion of CJD. DWI is the most sensitive MRI technique in the diagnosis of CJD, which supports an amendment to the clinical diagnostic criteria for sCJD to include findings from MRI.     

吸食海洛因致海绵状白质脑病的CT及MRI诊断

目的评价海洛因中毒所致的海绵状白质脑病的CT、MRI表现及诊断价值.方法搜集6例海洛因海绵状白质脑病的CT及MRI资料,全部患者均进行MRI检查,检查序列包括T1WI、T2WI、FLAIR序列,其中2例同时行颅脑CT扫描. 结果全部患者MRI显示对称性双侧小脑半球、大脑半球后部、内囊后肢、胼胝体压部、脑干等皮质下白质为主的多发性大片状长T1、长T2信号,加强后病灶无强化;2例行头颅CT检查显示两大脑半球皮质下白质、基底节及两侧小脑呈对称性广泛低密度灶,无占位效应.结论海洛因中毒所致的海绵状白质脑病具有特征性的MRI表现,MRI对本病的诊断具有重要价值.     

磁共振成像对肾上腺脑白质营养不良的诊断价值

报告４例肾上腺脑白质营养不良（ＡＬＤ）患者的磁共振成像（ＭＲＩ）表现。ＭＲＩ表现为双侧对称的白质异常信号，主要位于枕、顶、颞叶，视放射和胼胝体压部，Ｔ１加权为低信号，Ｔ２加权为高信号，有增强效应。多维成像和高对比强度使ＭＲＩ比ＣＴ有更强的敏感性，能明确病变的部位及其严重程度，故ＭＲＩ是诊断ＡＬＤ的有效手段。     

A case of Marchiafava-Bignami disease demonstrated by MR diffusion-weighted image]

A Case of Marchiafava-Bignami disease demonstrated by MR diffusion-weighted image (DWI) was reported. A 55-year-old male with chronic alcoholism demonstrated dysarthria, disorientation and apraxia of left-hand. Sagittal view on MRI showed a swelling of the corpus callosum. The body and splenium of the corpus callosum showed symmetrically iso-intensity in T1 WI and hyperintensity in T2 WI, and remarkable hyperintensity in fluid attenuated inversion recovery images. DWI showed a definite hyperintensity area on the corpus callosum and the apparent diffusion coefficient (ADC) map presented the decreased water self-diffusion. These findings differed from the other demyelinating diseases, such as multiple sclerosis. We considered these DWI findings were the initial changes on MBD which preceded the demyelination. To our knowledge, this is the first report of DWI that was used in a case of Marchiafava-Bignami disease.