沃勒变性在中枢神经系统的MRI表现

目的：回顾沃勒变性及继发跨神经元退变的病理学改变，分析其在中枢神经系统的MRI表现。方法：根据沃勒变性的影像学标准，选择1995-1999年经MRI确诊的沃勒变性患20例，年龄16-70岁，平均52岁。其中脑梗死11例，脑出血4例，创伤手术后2例，肿瘤术后1例，脑膜瘤1例，脑白质病1例。回顾性分析其MRI表现。结果：20例患原发病灶位于幕上，16例于原发病灶同侧出现条带样连续或不连续长T1或等T1、长T2改变，位于皮质脊髓束通路。FLAIR及DWI扫描均显示高信号病灶。3例仅见原发灶同侧大脑脚萎缩，但未见异常信号。7例见局限性胼胝体萎缩，T2加权像信号略显增高。2例患出现交叉性小脑萎缩，示皮质脑桥小脑通路退变。结论：对中枢神经系统的沃勒变性和继发跨神经元退变描述的是分子水平的病理学变化，因变性是沿着已知的神经通路的、且存在特定信号改变，故MRI可在活体中对其进行观察和诊断。     

脑锥体束Wallerian变性的临床及影像分析

目的观察并总结脑锥体束Wallerian变性的临床及影像表现。方法搜集64例脑损害后出现脑锥体束Wal-lerian变性患者的临床及影像资料,分析并总结。结果脑损害后发生的脑锥体束Wallerian变性临床表现为继发性对侧肢体无力,肢体远端症状较近端明显,CT表现为与病灶同侧的锥体束呈稍低密度影,MRI表现为与病灶同侧的锥体束呈等T1或长T1长T2信号,T2-Flair序列呈高信号,DWI早期呈高信号,后期呈等信号,晚期出现脑干同侧的局限性萎缩。结论脑损害累及锥体束可导致锥体束Wallerian变性,临床表现需与脑梗死所致肢体无力鉴别,影像表现有特征性。     

颅内表皮样囊肿20例

目的探讨颅内表皮样囊肿(EC)的临床与头颅MRI影像表现,以便提高诊断率。方法经手术病理证实的20例EC的MRI表现。全部患者均进行了常规平扫序列T_1WI、T_2WI、液体衰减反转恢复序列(FLAIR)及弥散加权成像(DWI)、钆对比剂增强扫描(CE-MRI)检查。结果 20例肿瘤脑桥小脑角池12例(左侧7例,右侧5例),桥前池3例,脑实质内2例(右侧枕叶1例,左侧额叶1例,病灶均发生于皮质区或皮质下区),左侧外侧裂池1例,枕大池1例,四脑室1例。其中4例病灶同时受累桥前池、鞍上池、侧裂池及环池等多个脑池间隙;全部病灶均呈囊性改变;13例长T_1WI、长T_2WI信号,4例T_1WI、T_2WI为混杂信号,3例T_1WI、T_2WI均为高信号;11例T_2FLAIR序列检查结果均呈混杂信号,其内可见散在的絮状稍高信号影,6例为低信号,3例为稍高信号;DWI序列检查结果为19例高信号,1例低信号。结论 EC的MRI表现具有特征性,尤其是FLAIR及DWI序列MRI表现有助于对该病的明确诊断。     

继发于脑桥缺血性卒中的双侧小脑中脚Wallerian变性

正Wallerian变性系轴索顺行性崩解及其所属髓鞘变性的过程,是继发于神经元胞体和近端轴索损伤的退行性变,最常累及皮质脊髓束和皮质脑桥束,累及脑桥-小脑通路者并不少见,但鲜为人所熟知。脑桥小脑束起源于对侧脑桥核(位于脑桥基底部),接受皮质脑桥束的传入,在脑桥上部水平交叉过中线,经小脑中脚达小脑皮质。当损害发生在一侧脑桥时,同侧脑桥核、     

脑桥出血继发肥大性下橄榄核变性的影像分析

目的分析脑桥出血继发肥大性下橄榄核变性(hypertrophic olivary degeneration,HOD)的MRI影像学特点,以期提高对HOD的诊断水平。方法回顾性分析6例脑干出血后继发HOD的MRI表现,均行MRI常规序列和DWI、SWI序列扫描。结果 MRI表现为同侧或双侧下橄榄核体积增大或无明显变化,T1WI呈等或稍低信号,T2WI呈稍高或高信号,FLAIR呈等或稍高信号,DWI呈等信号,ADC图呈稍高信号,SWI无异常信号,对出血病灶显示最好。结论 MRI能非常清楚地显示下橄榄核的变性改变,但需结合临床病史、症状与体征才能对HOD作出明确诊断。     

MRI在颅内胚胎发育不良性神经上皮瘤诊断中的价值

目的探讨胚胎发育不良性神经上皮瘤(DNT)的MRI影像表现与临床病理特点,提高对胚胎发育不良性神经上皮瘤的认识。方法回顾性分析8例手术病理证实的胚胎发育不良性神经上皮瘤患者的MRI表现与临床病理特点。结果 8例患者中,男3例,女5例,均有癫痫病史;病灶累及大脑半球皮层及皮层下,其中颞叶5例、额叶2例、颞顶叶1例;MRI表现为长T_1、稍长T_2信号,其中1例T1WI高低混杂信号;4例病灶呈类三角形,3例病灶内多发小囊变,1例病灶呈类圆形。7例病灶周无水肿。增强后6例病灶无强化,2例病灶轻度强化。病理学显示肿瘤主要由少突胶质细胞样细胞、神经元和星形细胞组成。临床上该病好发于儿童或年轻人。结论 DNT属于良性肿瘤,其MRI表现具有一定特征,结合临床及影像表现,应考虑到本病的可能性。     

脱髓鞘假瘤五例临床分析

目的回顾分析5例经病理学证实的脱髓鞘假瘤患者的临床表现、影像学和病理学特点、治疗及预后。方法与结果共5例经术后病理学证实的脱髓鞘假瘤患者,均为男性,临床主要表现为肢体无力(3例),头晕和记忆力减退(2例),癫发作(1例);头部MRI显示占位效应,呈T_1WI低信号、T_2WI和FLAIR成像高信号,增强扫描病灶多呈强化征象,其中3例为开环状强化;手术全切除(4例)或部分切除(1例)病变;术后病理学提示炎性脱髓鞘改变;1例复发后死亡,4例预后较好。结论脱髓鞘假瘤是表现为占位效应的炎性脱髓鞘病变,应注意与中枢神经系统肿瘤相鉴别,以避免不必要的手术治疗和放射治疗。     

Wallerian变性

正Waller于1850年率先描述动物周围神经离断后,远端轴索及其髓鞘顺行性改变,称为Wallerian变性(WD)。中枢神经系统Wallerian变性系神经元胞体损害或轴突离断后,远端和部分近端轴索及其髓鞘变性、崩解过程。任何导致皮质和皮质下神经纤维通路功能障碍的病变,如缺血性或出血性卒中、肿瘤、脱髓鞘病变、颅脑创伤、手术等均可以导致Wallerian变性。皮质     

脑损害后锥体束Wallerian变性的磁共振诊断分析

目的探讨脑损害后锥体束Wallerian变性的磁共振诊断价值。方法回顾性分析155例脑损害后锥体束Wallerian变性患者磁共振资料。结果脑损害后锥体束Wallerian变性在磁共振上直接征象为与病灶同侧沿锥体束走行路径条状等T1或长T1长T2信号,T2Flair序列常呈高信号,间接征象为与脑损害同侧的脑干萎缩。结论磁共振可明确显示脑损害后锥体束Wallerian变性,不同于腔隙性脑梗死。     

进行性皮质下胶质细胞增生症:不应忽视的神经变性痴呆

进行性皮质下胶质细胞增生症是临床少见的神经变性痴呆,病理学特点主要是额叶、颞叶等部位星形胶质细胞增生;临床表现为人格改变、进行性痴呆、构音障碍和肌阵挛等;头部MRI可见与神经胶质增生相关的T_2WI高信号。由于临床表现和辅助检查缺乏特异性,明确诊断主要依靠尸体解剖。神经影像学与特征性病理改变相结合必将为进行性皮质下胶质细胞增生症的生前诊断带来希望。     

Retrospective case-analysis of the magnetic resonance imaging characteristics in the brain of patients with Wilson disease

BACKGROUND:Wilson disease (WD)damages liver,brain,kidney,cornea and nervous system severely.It is manifested in four ways:brain,liver,kidney and bone muscle.Whether or not magnetic resonance imagling (MRI)can clearly display the diseased region and range in brain of patient with WD,which provides imageological evidence for clinical practice,is unclear.OBJECTIVE:To observe the charactedstics of MRI of brain in patient with SD,and analyze the correlation of diseased region with clinical symptoms.DESIGN:Retrospective case-analysis.SETTING:Department of Radiology,Second Hospital Affiliated to the General Hospital of Chinese PLA.PARTICIPANTS:Thirty-one patients,including 18 males and 13 females,with WD admitted to the Department of Neurology,Second Hospital Affiliated to the General Hospital of Chinese PLA between January 1999and December 2005 were retrieved.The involved patients presented serum copper oxidase (sCP) activity decreasling and/or caruloplasmin Ievel decreasling and/or urinary copper content increasling;typical extrapyramidal symptoms and/or physical sign;abnormality showed by slit-lamp examination,Kayser-Fleischer rling positive.METHODS:①All the involved patients underwent MRI examination.A GE 1.5T imagling equipment was used.Spin-echo sequence was adopted to perform T2 and T1-weighed image at transverse axis level.Partial cases subjected to head scannling at coronal and/or sagittal level.Gd-DTPA With dosage of 0.1 mmol/kg was the strongest in 4 cases.②MRI characteristics of patients with dliferent clinical symptoms were observed.MAIN OUTCOME MEASURES:MRI detection results of patients with WD and MRI characteristics of patients with different clinical symptoms.RESULTS:Thirty-one patients with WD participated in the result analysis.①Imageological examination results:WD lnvolved many regions in the brain:dorsal caudate putamen(n=28),thalamencephalon(n=25),mesencaphalon(n=25),globus pallidus(n=23),pons(n=21),posterlor limb of intemal capsule(n=16),dentate nucleus(n=16),caudata nucleus(n=15)and cerebral cortex(n=11).MRI presented hypo-intensity signal on T2-weighted image and T1-weighted image or isointensity signal on T1-weighted image in 24 patients,characteristic hypo-intensity signal of globus pallidus in 4 patients,mixed signal of hyper-and hypo-intensity in 2 patients,hypo-intensity signal of globus pallidus,pars anterior pedunculi carebd and pontine tegmentum on T1-weighted image in 1 patient.Pathological changes distdbuted in symmetry and focus of infection mostly presented mottling,lamellar or strip.Different degrses of cerebral cortex atrophy,especially subtentodal cerebellar atrophy,ware found in 20 patients.Four patients subjected to enhancement scannling,but no clear imaqling was found.③MRI characteristics of patients with different symptoms:Abnormal signal of dorsal caudate putamen was found in 28 patients with dystonia,21 patients with dysarthda and 16 patients with bradykinesia;Abnormal signal of mesencaphalon was found in 22 patients with trepidation,among which,18 presented abnormal signal of pons;Abnormal signal of caudate nucleus and lenticular nucleus was found in 15 patients with dysphagia;Abnormal signal of dentate nucleus was found in 16 patients with carebellar ataxia;Different degrees of changes in cerebral atrophy were found in 14 patients with detedoratling memory and dementia.CONCLUSION:MRI can clearly display the characteristics of diseased regions in brain of patient with WD.Diseased regions reflected by MRI have obvious differences in patients with different clinical neurosigns.     

肝型和无症状型肝豆状核变性颅脑磁共振分析

目的观察肝型和无症状型的肝豆状核变性颅脑MRI表现。方法对我院2014年5月-2016年5月收治的97例肝型和28例无症状型WD患者,均行头部MRI检查。结果 125例患者中颅脑磁共振检查发现有108例患者(87.8%)有脑部异常信号样改变,其中肝型83例,无症状型25例;83例有脑萎缩改变,肝型63例,无症状型20例。结论肝型和无症状型肝豆状核变性患者颅脑MRI异常信号比例较高,主要集中在壳核;信号改变主要为对称性长T_1和长T_2,未发现有混杂样信号改变;病程与脑干和壳核相关,发病年龄与壳核、苍白球、尾状核密切相关;Child-Pugh分级与颅脑磁共振改变没有明显相关性。     

麻痹性痴呆的MRI表现(附32例报道)

目的 探讨麻痹性痴呆(GPI)的MRI特征和诊断价值,提高对GPI患者MRI表现的认识.方法 中山大学第三附属医院放射科自2006年5月至2010年11月共诊断GPI患者32例,回顾性分析患者的临床资料并总结GPI的MRI表现.结果 本组患者的MRI表现分为两型:脑萎缩型(30例)和脑肿胀型(2例),其中脑萎缩型GPI的MRI表现为:(1)以颞叶、额叶、海马、胼胝体萎缩为主,脑白质萎缩较脑皮质萎缩明显;(2)杏仁体及海马形态异常及伴T2信号增高;(3)皮层/皮层下"脑回状"T2信号增高,以岛叶多见;(4)双侧豆状核对称性T2信号减低;脑肿胀型GPI的MRI表现为弥漫型或局灶型.结论 GPI的MRI表现多样,但具有一定特征性,结合临床表现和相关实验室检查结果可作出正确诊断.

Abstract：

Objective To evaluate the MRI findings in patients with general paresis of insane (GPI) to enhance the understanding of MRI diagnosis of this disease. Methods The clinical data and MRI findings of 32 patients with GPI, admitted to our hospital from May 2006 to November 2010, were retrospectively analyzed. Results The MRI findings of GPI were mainly divided into 2 types: cerebral atrophy (n=30) and cerebral swell (n=2). The major MRI findings in the type of cerebral atrophy included white cerebral atrophy in the temporal lobe, the frontal lobe, the hippocampus and the corpus callosum, morphological changes and T2 hyperintensity in the amygdaloid body and the hippocampus, gyral T2 hyperintensity in the cortex and subcortex, and T2 hypointensity in the lenticular nucleus. The MRI findings in the type of cerebral swell manifested as suffused and focal types. Conclusion The MRI findings in GPI are multiple with some characteristic manifestations. Diagnosis must be made through the combination of imaging features with clinical data and related laboratory tests.     

Volumetric quantitation by MRI in primary progressive multiple sclerosis: volumes of plaques and atrophy correlated with neurological disability

In primary progressive multiple sclerosis (PPMS) abnormalities in brain magnetic resonance imaging (MRI) differ from abnormalities in other subtypes of multiple sclerosis (MS). It was investigated whether the extent of brain and spinal cord MRI abnormalities is reflected in the neurological disability in PPMS. Focal and diffuse changes and atrophy in central nervous system (CNS) in patients with PPMS (n = 28) and healthy controls (n = 20) were assessed by semi-automatic MRI segmentation and volumetric analysis. The measurements were related to neurological disability as expressed by the expanded disability status scale (EDSS), the regional functional scoring system (RFSS), the arm index and the ambulation index. Plaques in T1- and/or T2-weighted images were seen in all brains, while spinal plaques were detected in 23 of 28 patients (82%). The total volumes of brain and spinal cord were significantly smaller in patients than in controls (P = 0.001 and 0.000, respectively). The volumes of T1 or T2 lesions in the brain correlated to the ambulation index (r = 0.51, P = 0.005 and r = 0.53, P = 0.004, respectively). No correlations were detected between MRI measurements and total EDSS score, but relative brain atrophy correlated inversely with the total RFSS scores, poor arm index and higher cerebral disturbances (r = -0.53, P = 0.004; r = -0.53, P = 0.004; and r = -0.52, P = 0.005, respectively). Although the number of spinal T2 lesions correlated with sensory disturbances (r = 0.60, P = 0.001), no correlations were found between EDSS subscores and spinal cord atrophy. These findings show that marked atrophy of brain and spinal cord detected by volumetric quantitation correlates with neurological disability. This observation indicates the importance of neurodegenerative events in PPMS.     

Do MRI features distinguish Wilson's disease from other early onset extrapyramidal disorders? An analysis of 100 cases

Magnetic resonance imaging (MRI) is frequently used in the evaluation of various extrapyramidal disorders. Among the plethora of MRI features in Wilson's disease (WD), only “face of the giant panda” sign has been recognized to distinguish WD from other early onset extrapyramidal disorders (EOEPD). To ascertain the value of various MRI features in differentiating neuropsychiatric form of WD from other EOEPD. This retrospective analysis included 100 patients (M:F = 56:44) of EOEPD (5–40 years), who had undergone MRI during Jan'03 to Nov'08. Their clinical features were recorded and the following MR sequences were analyzed: T1WI, T2WI, FLAIR. Fifty‐six patients had WD (M:F = 28:30, age at onset: 14 ± 6.8 years) and 44 had other EOEPD (M:F = 27:17, age at onset: 19 ± 9.8 years) that included Huntington's disease‐4, young‐onset Parkinson's disease‐7, mitochondrial disorders‐2, Hallervorden‐Spatz disease‐8, non‐Wilsonian hepatolenticular degeneration‐2, toxic/metabolic disorder‐1, and others‐20. The duration of illness at the time of MRI was comparable (WD: 3.1 ± 4.9 years; Other EOEPD: 2.8 ± 2.4 years). MR signal characteristics varied in topography and severity in both the groups. All the patients of WD had signal abnormalities in MRI, as against 16/44 of the other EOEPD group. The following MR observations were noted exclusively in WD: “Face of giant panda” sign (14.3%), tectal plate hyperintensity (75%), central pontine myelinolysis (CPM)‐like abnormalities (62.5%), and concurrent signal changes in basal ganglia, thalamus, and brainstem (55.3%). Besides “Face of giant panda” sign, hyperintensities in tectal‐plate and central pons (CPM‐like), and simultaneous involvement of basal ganglia, thalamus, and brainstem are virtually pathognomonic of WD. © 2010 Movement Disorder Society     

非典型性颅内静脉窦血栓11例临床分析

目的分析非典型性颅内静脉窦血栓的临床特征及诊断方法,旨在加深对该病变的认识并探讨雌激素在其发病中的作用。方法对2000年3月～2002年8月诊断明确的11例男性颅内静脉系统血栓患者(平均年龄38.2岁)的临床表现、头部CT、MRI以及MRV等影像学资料进行回顾,分析其不同时期的影像学特点;并通过测定7例患者的血清雌激素水平探讨其发病原因。结果11例患者的阳性体征包括视乳头水肿(7例)、外展神经麻痹(4例)、肢体轻度瘫痪(3例)及脑膜刺激征(6例)。7例行血清雌激素检测者中,4例血清雌二醇水平及雌二醇与睾酮比值(E2/T)高于正常值。MR及MRV检查显示,单纯上矢状窦血栓3例,上矢状窦合并横窦血栓3例,上矢状窦合并横窦、直窦血栓5例;脑叶异常信号5例;脑叶合并基底节、丘脑异常信号1例。CT检查显示,3例呈现弥漫性脑水肿;3例脑叶见条索状高密度影;1例呈高密度三角征;蛛网膜下腔出血和顶叶出血各1例。结论对于无明确发病诱因的可疑颅内静脉系统血栓患者应及早行头部MR+MRV检查,以便于早期诊断。男性患者血清雌激素水平增高可能是发病的危险因素。     

The combination of hypointense and hyperintense signal changes on T2-weighted magnetic resonance imaging sequences: a specific marker of multiple system atrophy?

OBJECTIVE: To compare the frequency and specificity of hypointense magnetic resonance imaging (MRI) signal changes alone with the frequency and specificity of a pathological MRI pattern consisting of a hyperintense lateral rim and a dorsolateral signal attenuation on T2-weighted MRIs in patients with parkinsonism of various origins. PATIENTS: Ninety patients with Parkinson disease (PD) (n = 65), progressive supranuclear palsy (PSP) (n = 10), and multiple system atrophy (MSA) of the striatonigral degeneration type (n = 15) underwent MRI. SETTING: University medical center. RESULTS: Nine of the 15 patients with MSA showed the pattern with hyperintense lateral rim and a dorsolateral hypointense signal attenuation on T2-weighted images within the putamen. This pattern was not found in the 65 patients with PD, nor in the 10 patients with PSP. Only hypointense changes in the putamen were found in 6 patients (9%) with PD, 4 patients (40%) with PSP, and 5 patients (36%) with MSA. CONCLUSIONS: Our data suggest that the pattern consisting of hypointense and hyperintense T2 changes within the putamen is a highly specific MRI sign of MSA, while hypointensity alone remains a sensitive, but nonspecific MRI sign of MSA. In clinically doubtful cases, the appearance of a hypointense and hyperintense signal pattern on MRI makes the diagnosis of PD very unlikely, while hypointense signal changes alone do not exclude idiopathic PD.     

Magnetic Resonance Imaging of Corticobasal Degeneration

Corticobasal degeneration (CBD) is an adult–onset, progressive parkinsonian syndrome with strikingly asymmetrical features, and signs and symptoms referable to both cerebral cortex and basal ganglia. Although once considered rare, it is now recognized with increasing frequency during life. Eight patients with clinically diagnosed CBD and 8 age– and sex–matched patients with Parkinson's disease underwent high–field–strength magnetic resonance imaging (MRI) of the brain. MRIs were graded by a blinded neuroradiologist using a semiquantitative (0–3) scale. MRI of patients with CBD revealed significantly greater T2–weighted signal hypointensity in the putamena and globi pallidi, and ventricular enlargement. When specifically sought, asymmetrical cortical atrophy was identified in 5 of 8 CBD patients. Increased T2–weighted lenticular signal hypointensity, ventricular enlargement, and asymmetrical cortical atrophy are supportive MRI findings of CBD.     

Magnetic resonance imaging and brain-stem auditory evoked potentials in neuro-Behcet's disease

We studied central nervous system lesions in patients with neuro-Behcet's disease using magnetic resonance imaging (MRI) of the brain and recording of brain-stem auditory evoked potentials (BAEPs). MRI revealed abnormal findings in seven of eight patients. MRI studies demonstrated extensive regions with high intensity signal in the brain stem and/or basal ganglia on T2-weighted images obtained during the acute stage of the disease in three patients. One of these patients had a strongly gadolinum-enhanced round lesion in the lower pons. In four of the other five patients with chronic disease, brain-stem atrophy was observed on T1-weighted images. Atrophic changes were more severe in the brain stem than in the cerebellum. Abnormal BAEPs were observed in three patients and consisted of prolongation of interpeak latency of waves III-V and defects of wave III or V. Abnormal BAEPs were recorded in patients with severe inflammatory changes or progression of atrophic changes in the brain stem. Our findings show that MRI and BAEPs are useful in detecting the presence and assessing the degree of neurological involvement in patients with neuro-Behcet's disease.     

Hypointense transcerebral veins at T2*-weighted MRI: a marker of hemorrhagic transformation risk in patients treated with intravenous tissue plasminogen activator.

Prediction of hemorrhagic transformation (HT) in patients treated by intravenous recombinant tissue-type plasminogen activator (rt-PA) is a challenging issue in acute stroke management. HT may be correlated with severe hypoperfusion. Signal changes may be observed at susceptibility-weighted magnetic resonance imaging (MRI) within large perfusion defects. A signal drop within cerebral veins at T2*-weighted gradient-echo MRI may be expected in severe ischemia, and may indicate subsequent risk of HT. The authors prospectively searched for an abnormal visibility of transcerebral veins (AVV) within the ischemic area in patients with hemispheric ischemic stroke, before they were treated with intravenous rt-PA therapy. Any correlation between AVV and baseline clinical or MRI findings, or further HT, was noted. An AVV was present in 23 of 49 patients (obvious, n = 8; moderate, n = 15), and was supported by severe hemodynamic changes at baseline MRI. The AVV was correlated with the occurrence of parenchymal hematoma type 2 at computed tomography during the first week (r = 0.44, P = 0.002). Five of six type 2 parenchymal hematomas occurred in association with obvious AVV. At multiple regression analysis, two baseline MRI factors had an independent predictive value for HT risk during the first week: the AVV and the cerebral blood volume ratio (Nagelkerke R2 = 0.48).