小脑半球肿瘤性病变的MRI、CT诊断

目的探讨发生于小脑半球肿瘤性病变的MRI和CT表现,以提高诊断水平。资料与方法对39例经临床手术病理证实的小脑半球各类肿瘤性病变的影像学资料进行回顾性分析,所有病例均进行MRI平扫及增强扫描,10例行CT扫描。结果39例均单发于一侧小脑半球,其中,血管母细胞瘤15例,毛细胞型星形细胞瘤6例,转移瘤5例,髓母细胞瘤3例,室管膜瘤2例,神经节细胞胶质瘤1例,其他胶质瘤3例,淋巴瘤1例,血管畸形3例;各种病变均有一定的临床及影像表现特点,部分肿瘤表现相似需加以鉴别,部分少见肿瘤的定性诊断有难度。结论发病年龄及MRI、CT特征性表现对于小脑半球肿瘤的诊断及鉴别诊断具有重要价值。     

小脑半球肿瘤的MRI诊断与鉴别诊断

目的:分析小脑半球肿瘤的MRI表现及鉴别诊断。方法:回顾性分析42例经手术及病理证实的小脑半球肿瘤的MRI表现。结果:星形细胞瘤15例,单发转移性肿瘤10例,血管母细胞瘤8例,髓母细胞瘤6例,恶性淋巴瘤2例,室管膜瘤1例。结论:MRI能清晰显示小脑半球肿瘤的部位、大小、形态、信号强度和边缘等特征,具有重要的诊断价值。     

儿童小脑半球髓母细胞瘤MRI误诊原因分析

目的 探讨儿童小脑半球髓母细胞瘤MRI误诊的原因，提高对髓母细胞瘤的认识。方法 手术病理证实的小脑半球髓母细胞瘤8例，回顾性分析其MRI表现及误诊原因。结果 3例呈囊性改变，增强扫描可见不规则环形强化，误诊为星形胶质细胞瘤；2例呈囊实性改变，实性部分明显强化，误诊为室管膜瘤；3例呈较均一实性肿块，明显强化，误诊为实性血管母细胞瘤2例、脑膜瘤1例。结论 由于不典型的发病部位及MRI表现，儿童小脑半球髓母细胞瘤常易误诊。年龄、信号特点及发病部位对诊断髓母细胞瘤有重要参考价值。     

儿童胶质母细胞瘤的 MRI 表现及文献复习

目的：探讨儿童胶质母细胞瘤(GBM)的 MRI 表现,提高对本病的认识。方法收集经手术病理证实的5例儿童 GBM的临床及 MRI 资料,回顾性分析肿瘤发生部位、形态、生长方式、瘤周水肿及信号强化特点。结果5例病灶位于大脑半球4例,小脑半球1例,均占位效应明显,其中跨中线结构生长2例;3例呈类圆形,2例呈不规则形。1例瘤周无水肿,4例瘤周轻-中度水肿。囊性1例,囊实性2例,实性2例;囊性部分呈长 T1长 T2信号,FLAIR 呈低信号,DWI 扩散未受限制;实性部分呈等 T1等 T2信号,FLAIR 呈高信号,DWI 受限呈高信号。增强扫描囊性病变嚢壁呈环形强化,边界清晰;囊实性病变实性部分呈环状、结节样强化;实性病变呈明显不规则、团块样强化。结论儿童 GBM 的 MRI 具有一定的特征性表现,确诊需手术病理证实。     

髓母细胞瘤的CT和MRI诊断

目的：提高非典型髓母细胞瘤的CT和MRI的诊断准确率。材料和方法：经手术及病理证实的髓母细胞瘤40例，年龄5～35岁。CT检查34例，其中28例同时作增强扫描。MRI检查38例，30例作增强扫描。32例同时作CT和MRI检查。结果：CT和MRI对髓母细胞瘤的定位诊断正确率为100％，定性诊断正确率为87．5％（35／40）。肿块位于小脑蚓部25例，小脑半球9例，四脑室内6例。肿瘤囊变26例，钙化3例，有例增强不明，3例出现转移，转移沿脑脊液播散。结论：非典型髓母细胞瘤可以发生在四脑室内，小脑半球，可以出现大的囊变、钙化，也可以增强不明显，掌握这些征象是CT和MRI诊断非典型髓母细胞瘤的关键。     

Crossed cerebellar diaschisis and crossed cerebellar atrophy: correlation of MR findings, clinical symptoms, and supratentorial diseases in 26 patients.

Crossed cerebellar diaschisis is a condition in which cerebellar hypometabolism is ascribed to functional disconnection of the contralateral hemisphere from the cerebral cortex. Interruption of the cerebropontine-cerebellar pathway is thought to be the most likely mechanism of this remote transneuronal metabolic depression. This phenomenon can be diagnosed by positron emission tomography, as there is hypometabolism in the affected cerebellar hemisphere. The morphologic features of the affected cerebellar hemisphere in patients with the diagnosis of crossed cerebellar diaschisis have not previously been studied by MR imaging. We retrospectively reviewed 26 patients in whom the diagnosis of crossed cerebellar diaschisis was suggested by positron emission tomography; these patients also had MR studies. In all 26 patients, supratentorial diseases were documented by MR imaging. Twenty-four of the 26 patients had a pathologic diagnosis. Detailed clinical history was also obtained for all patients. MR findings of morphologic change in the affected cerebellum were correlated with the patient's clinical symptoms and supratentorial disease. Of the 26 patients, eight had cerebellar atrophy; the remaining 18 patients showed no MR abnormality of the affected cerebellum. In the 18 in whom no atrophy was seen on MR imaging, the majority of the supratentorial lesions were tumors. The eight patients in whom cerebellar atrophy was demonstrated usually had significant contralateral supratentorial hemispheric atrophy. The patients with atrophy were also generally younger (average age, 14 years) than the 18 patients without cerebellar atrophy (average age, 42 years). Our experience shows that a significant number of patients with crossed cerebellar diaschisis have morphologic changes of cerebellar atrophy shown by MR imaging. These patients usually have significant contralateral supratentorial hemispheric atrophy.     

枫糖尿病的临床和脑磁共振成像特点

目的：探讨枫糖尿病(MSUD)脑 MRI 表现及其诊断价值。方法经气相色谱、串联质谱、基因确诊9例 MSUD 患儿,通过 MRI 了解脑损伤特点,结合临床表现、生化特点进行分析,重点分析影像学表现。结果9例患儿于生后3 d~6岁发病,临床表现缺乏特异性,主要是喂养困难、昏睡、反应差、抽搐发作、智力下降。患者血亮氨酸、异亮氨酸、缬氨酸显著增高。9例均行 MRI 检查,2例同时行氢质子磁共振波谱(1 H-MRS)检查。脑 MRI 显示小脑半球、小脑脚、大脑脚、脑干、苍白球各有5例受累,4例累及丘脑、内囊后肢,3例累及半卵圆中心,2例同时合并胼胝体、枕部、颞叶深部、额叶、顶叶信号异常。受累的区域均表现为 T1稍低、T2稍高信号,而在扩散加权成像(DWI)上表现为明显高信号。1例影像正常。2例1 H-MRS 于0.9 ppm 处均未见甲基峰。结论MSUD 临床表现缺乏特异性,MRI 特点主要是生后已经开始髓鞘化的脑白质区域如小脑半球、内囊后肢、脑干内、小脑脚、大脑脚等在 DWI 上表现为明显高信号。     

中枢神经系统黑色素细胞肿瘤的MRI诊断

目的：探讨中枢神经系统黑色素细胞肿瘤的MRI特征。方法：回顾性分析16例经手术病理证实的中枢神经系统黑色素细胞肿瘤的临床资料及MRI资料,观察肿瘤MRI上的形态学特征及信号表现。结果：16例黑色素细胞肿瘤,男10例,女6例。年龄17～55岁。肿瘤位于颈段椎管内3例,额叶3例,颞叶2例,桥脑小脑角区1例,鞍区1例,小脑半球2例,脑内及脑膜多发者3例,全脑脊膜1例。肿瘤发生于颅底脑外者占17%,发生于近颅底脑实质者占43%。MRI信号特征典型者6例,不典型者10例,其表现为短T1等T2信号、或不均匀短T1等T2信号,或因瘤体卒中而呈囊实性混杂信号,增强扫描呈不均匀强化。结论：中枢神经系统黑色素细胞肿瘤可不具典型的MRI信号特征。对于发生于颅底及颈段软脊膜的有混杂T1或T2信号的肿瘤,在鉴别诊断时应考虑到该瘤的可能。     

小脑髓母细胞瘤的MRI影像特征及鉴别诊断

目的:探讨小脑髓母细胞瘤的MRI表现及鉴别诊断。方法:回顾性分析21例经手术病理证实的小脑髓母细胞瘤的MRI资料,所有病例均行MRI平扫及增强扫描,5例行FLAIR序列及弥散加权成像(DWI)。结果:21例髓母细胞瘤中,19例位于小脑蚓部(占90%),2例位于小脑半球(占10%)。发病年龄5～41岁,15岁以下11例(占52%)。肿瘤平均大小约33mm,18例病灶边界较清楚,3例病灶周边模糊。圆形或类圆形11例,不规则形3例,边缘分叶5例。16例病灶内可见囊变、坏死。MRI扫描,T1WI呈稍低、等信号,T2WI呈等、稍高信号,FLAIR序列呈等、稍高信号,DWI序列病灶实性成分呈高信号,表面扩散系数(ADC)图呈略低信号。增强扫描大部分病灶不同程度强化。12例病灶周边见不规则水肿。结论:小脑髓母细胞瘤具有典型好发部位及特征性MRI影像表现,早期诊断有助于临床治疗及提高患者生存质量。     

Aspects of the anatomy of the cerebellum on computed tomography

Summary The salient features of the normal CT anatomy of the various lobules of the cerebellar hemispheres and vermis are described. The subdivisions of the vermis were found to be most constant. The surface appearance of the hemisphere lobules was also relatively constant; however, at CT these fissures are imaged at depth and this constancy is not reflected in CT images because folia cross the depths of the major sulci from one lobule to the other in a highly variable manner. The flocculus has been confused with the anterior angle of the cereellum, and the cerebellar tonsils with the biventral lobule.     

儿童小脑良性星形细胞瘤的MRI特征

目的　探讨MRI在儿童小脑良性细胞瘤 (BCAs)诊断中的价值。方法　对 12名BCAs患儿临床及MRI资料进行回顾性分析。结果　 12例肿瘤中 7例定位于小脑半球 ,4例位于蚓部 ,1例位于第四脑室内。所有患儿均有脑积水 ,其中重度 9例 ,中度 3例。最常见的临床表现为头痛和呕吐 ,肿瘤直径为 2 3～ 68mm ,平均 42mm。 12例中 7例为囊性瘤 ,5例为实体瘤。与正常脑实质比较 ,在T1WI上 ,10例BCAs表现为为低信号影 ,9例在T2 WI上表现为高信号影。静脉注射对比剂后 ,12例中有 2例明显增强 ,5例为中度增强 ,5例未增强。出血和钙化分别为 1例、0例。结论　BCAs在MRI上的表现具有相对特征性 ;MRI对于BCAs的诊断和手术治疗方案的制定具有重要意义。     

Cerebral atrophy and crossed cerebellar atrophy following acute subdural hematoma in infant

Crossed cerebellar atrophy (CCA) on imaging study reflects secondary degeneration of the cerebellar hemisphere caused by neuronal disconnection with the contralateral cerebral hemisphere. We report an 11-month-old child with traumatic left acute subdural hematoma, who showed crossed cerebellar atrophy on MR images. Eighteen months after the trauma, MR images showed brain atrophy not only in the left cerebral hemisphere but also in the right cerebellar hemisphere. The cerebellar atrophy was prominent in the lateral part. This finding is consistent with CCA and may support neuronal interactions between the cerebral hemisphere and the lateral part of the contralateral cerebellar hemisphere.     

肺癌颅脑单发转移瘤的CT表现(附49例分析)

目的：研究肺癌颅脑单发转移瘤的CT表现特征。方法：回顾性分析经手术、病理和临床证实的49例肺癌颅脑单发转移瘤的CT表现及其中35例行手术切除病例的外科及病理所见。结果：发生于大脑半球的肺癌脑转移瘤40例，发生于小脑半球的肺癌脑转移瘤8例，发生于颅骨的1例。多数肺癌脑单发转移瘤呈实质部分明显强化的环形，其中可见囊腔(28／35)。囊壁厚薄不均及壁结节多见于肺癌脑单发转移瘤而非脑脓肿。瘤周水肿多呈中到重度(33／49)，且瘤灶大小与其周边水肿不成比例。肺癌脑转移瘤的典型CT表现是“掌趾征”，本组有7例可见此征像。结论：瘤灶呈环行囊腔表现及“掌趾征”是肺癌脑单发转移瘤的典型CT表现。     

继发于自发性颅内出血的神经源性肺水肿的影像学表现

目的:探讨自发性颅内出血并发神经源性肺水肿(NPE)的影像表现及与临床表现的相关性.方法:回顾性分析经临床证实的自发性颅内出血并发NPE的5个病例,均行CT平扫及胸部X线片检查,分析其表现及临床特征.结果:5例自发性颅内出血并发NPE中,脑干出血2例,小脑出血1例,大脑半球出血1例,自发性蛛网膜下腔出血1例.4例血肿均有破入临近脑室和/或蛛网膜下腔.5例患者的胸部X线片均示不同程度的肺水肿改变.治愈2例,死亡3例.结论:自发性颅内出血并发NPE患者的头颅CT均可见程度不同的颅内出血改变,其肺部表现为轻重不等的肺水肿征象,排除原发心、肺疾患及输液过快等因素,均应提示NPE,以免贻误抢救时机.     

颅内成血管细胞瘤的MRI特征

目的:探讨MRI在颅内成血管细胞瘤诊断中的价值。方法:对21例经手术及病理证实的颅内成血管细胞瘤患者的临床及MRI资料进行回顾性分析。结果:21例中术前正确诊断18例(85.7%),误诊3例(14.3%)。9例病灶位于小脑半球,7例位于小脑下蚓部,3例位于桥脑或脑干,2例位于大脑半球。14例为大囊小结节型或囊腔结节型(66.7%),主要MRI表现为囊性病灶和附壁结节,增强后瘤结节明显强化;2例单纯囊型(9.5%),MRI表现为囊性病灶,囊内无附壁结节,无明显强化;5例为实质型(23.8%),表现为实质性肿块,其内或周围可见流空血管,增强后肿瘤明显强化。结论:成血管细胞瘤MRI表现具有相对特征性,MRI对于颅内成血管细胞瘤的正确诊断具有重要价值。     

颅内血管母细胞瘤的MRI表现与临床病理对照

目的探讨血管母细胞瘤的MRI影像表现与临床病理特点,提高其诊断准确率。方法回顾性分析18例经手术病理证实的颅内血管母细胞瘤MRI表现和临床病理特点。结果 18例病灶,5例位于右小脑半球,9例位于左小脑半球,3例位于小脑蚓部,1例位于幕上右侧脑室三角区;MRI表现为大囊小结节型9例,囊实型3例,单纯囊型1例,实质型5例。血管母细胞瘤典型MRI表现为大囊小结节,且小结节显著异常强化。大体病理学检查,肿瘤细胞以囊性和实质性两种形态,囊液透明、淡黄色、蛋白含量高,实性部分由丰富的血管和血窦构成;显微镜下见肿瘤由大小不等的血管腔隙和其间的基质细胞构成,在血管内皮细胞核周围细胞区见丰富的网状纤维;临床上该病好发于中青年,男性为主。结论血管母细胞瘤的MRI表现具有一定特征,结合临床较易诊断;对非典型的血管母细胞,则需进行鉴别诊断,MRI增强更有利于对病变的定性诊断。     

小脑发育不良性神经节细胞瘤3例的磁共振成像表现

目的分析小脑发育不良性神经节细胞瘤的影像学特征,提高对该病术前诊断的准确性。方法回顾性分析3例经手术病理证实的小脑发育不良性神经节细胞瘤的CT和磁共振成像(MRI)表现,并结合文献复习总结其影像学特征。结果 3例均为女性,发生在左侧小脑半球2例,发生在右侧小脑半球和四叠体池区1例,MRI表现为长T1WI、长T2WI信号,其内见条纹状等T1WI、等T2WI信号,增强扫描无强化;其中2例伴发脑积水,1例合并瘤内出血。结论小脑发育不良性神经节细胞瘤具有一定的影像学特征,典型表现者术前可作出定性诊断。     

Lhermitte-Duclos disease: MR diffusion and spectroscopy

AIM: To describe two cases of Lhermitte-Duclos disease studied with Diffusion MRI and MRi Spectroscopy. MATERIALS AND METHODS: Two patients showing a space-occupying lesion in the cerebellar hemisphere were studied by conventional MRI associated with Diffusion MRI and Spectroscopy. RESULTS: Conventional MRI showed the typical morphological pattern of Lhermitte-Duclos disease with a slow-growing cerebellar mass mainly involving the cortex and non-enhancing thickened cerebellar folia. The mass exerted mild compression of the IV ventricle causing hydrocephalus On Diffusion imaging showed the lesion to be hyperintense due to residual T2-activity and hypointense on the ADC map. Spectroscopy was typical with an increased lactate peak and a reduced choline peak, indicating abnormal anaerobic glycolysis and demyelination, respectively. DISCUSSION: Lhermitte-Duclos disease is a neurological condition which presents several signs and symptoms related to the cerebellar mass. Cowden's syndrome, an autosomal dominant neoplastic disorder with malignant features is associated in 40% of cases. MRI associated with functional examinations such as Diffusion Imaging and Spectroscopy is the imaging modality of choice in LDD patients. They allow a definite diagnosis as the neuroradiological findings correlate well with molecular biology theories regarding the malformative nature of dysplastic cerebellar gangliocytoma.     

中枢神经系统血管母细胞瘤的MRI诊断

目的:探讨MRI(常规及DWI等序列)在中枢神经系统血管母细胞瘤诊断中的应用价值。方法:对经手术病理证实的73例血管母细胞瘤共81枚病灶的MRI表现进行回顾性分析。结果:血管母细胞瘤多为单发(67/73),小脑为最常见发病部位(61/81),可分为3型:囊伴结节型53个,实质型22个,单纯囊型6个;DWI序列肿瘤结节及实质型瘤体均呈低信号;19个病灶表现有囊中囊征象。结论:血管母细胞瘤的MRI表现具有特征性,且与其病理基础密切相关,能为手术方式的选择提供依据。     

小脑星形胶质细胞瘤CT诊断(附36例分析)

目的：了解小脑星形胶质细胞瘤的ＣＴ表现。方法：对３６例经手术及病理证实的小脑星形胶质细胞瘤ＣＴ表现进行了回顾性分析总结。结果：小脑星形胶质细胞瘤大部分表现为囊性，其ＣＴ特征为：（１）环状壁厚薄不均匀强化，及壁结节强化伴钙化。（２）瘤周水肿轻，但均有程度不同的占位效应。结论：根据小脑星形胶质细胞瘤特殊表现，结合临床可作出正确诊断。