Neuronal tumors of the central nervous system: radiologic findings and pathologic correlation.

Pure neuronal and mixed neuronal-glial tumors of the central nervous system are uncommon but fascinating because they are less aggressive than the more common glial tumors and their prognosis is excellent. Neurologic manifestations are varied and include seizures, symptoms of increased intracranial pressure, and neurologic deficits according to tumor location. Many neuronal tumors of the central nervous system demonstrate characteristic radiologic findings. At magnetic resonance (MR) imaging, gangliocytomas demonstrate low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and frequent enhancement on gadolinium-enhanced T1-weighted images. Characteristic MR imaging findings of Lhermitte-Duclos disease are a nonenhancing mass in a cerebellar hemisphere with a striated pattern. Central neurocytomas are typically located in the lateral ventricles near the foramen of Monro with a characteristic attachment to the septum pellucidum. Ganglioneurocytoma is a rare variant of central neurocytoma that is characterized by differentiation toward ganglion cells. In ganglioglioma, a well-defined cystic mass with a solid mural nodule is typically seen. Extension of enhancement to the leptomeninges is characteristic of desmoplastic infantile ganglioglioma and correlates with the firm dural attachment of the solid component. Dysembryoplastic neuroepithelial tumor has a well-demarcated, multilobulated or gyriform appearance.     

中枢性原始神经外胚层肿瘤的影像表现与鉴别诊断

目的：探讨中枢性原始神经外胚层肿瘤(cPNET)的CT、MRI表现及鉴别诊断。方法回顾性分析经病理证实的15例cPNET患者的CT、MRI影像资料,总结其影像特征及鉴别诊断。结果本组cPNET病例平均年龄(8.82±2.53)岁,男女比例为9︰6。肿瘤均位于幕上,体积较大(平均直径约6.3 cm),多伴有小灶性或大片状坏死囊变(12/15),瘤周无水肿或轻度水肿。CT平扫肿瘤呈等、稍高或稍低密度,增强扫描较均匀或不均匀强化。MRI 平扫肿瘤实性成分 T1 WI 呈等或稍低信号,T2 WI 呈等或稍高信号, DWI大部分病例(12例)呈高信号,FLAIR呈等信号(9例)或稍高信号;增强扫描实性成分呈较均匀或小蜂窝状、不规则明显强化,坏死囊变成分未见强化。结论 cPNET具有一定特点,包括发病年龄较小、肿瘤大但界限较清且瘤周水肿轻或不明显、实性成分在DWI序列呈高信号、FLAIR序列呈等信号等。     

Imaging of central nervous system tumors

Magnetic resonance imaging has been used increasingly in the staging and evaluation of neoplasia of the brain and leptomeninges. In the classification of gliomas, the MR accuracy rate approaches that of pathologic diagnosis. Contrast-enhanced MR imaging has improved specificity in evaluating brain tumors in children and is now the preferred modality for evaluating leptomeningeal metastases of the brain and spine. MR imaging in children has also increased the specificity of histologic diagnosis in hypothalamic hamartoma and juvenile pilocytic astrocytoma. Gadolinium enhancement is most useful in patients older than 35 years of age who have focal neurologic complaints and certain disease histories. The expense of gadolinium contrast material is the major drawback to its routine use. In patients with seizure disorder, MR imaging is more sensitive than CT for detecting abnormalities such as mesial temporal sclerosis, tumors, and vascular malformations. Gadolinium enhancement may be useful in differentiating tumors from mesial temporal sclerosis. Recent reports on the use of MR spectroscopy for evaluating brain metabolism and tumors demonstrate that differences in metabolites exist. A correlation was found in epidermoid tumors between high signal on T1-weighted images and high lipid content, and several studies have shown a positive correlation between glioma grade and glycolytic activity as determined on 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography.     

Loco-regional extensions of central nervous system germ cell tumors: a retrospective radiological analysis of 100 patients

Purpose

The current staging system of central nervous system (CNS) germ cell tumors (GCT) includes a binary classification in “localized” or “metastatic” disease based on the absence or presence of leptomeningeal dissemination. Loco-regional tumor dissemination has been barely described whereas its accurate definition might be useful in terms of prognosis and treatment, especially for radiation therapy planning. Our purpose was therefore to describe MR patterns and prevalence of loco-regional extensions of these tumors.

Methods

One hundred consecutive patients (median age 16.3 years, range 7–41 years, sex ratio 7:1) with a histologically or biologically proven CNS GCT were retrospectively included. Brain and spinal MRI at diagnosis were reviewed by two neuroradiologists focusing on MR patterns of primaries and loco-regional extensions. When available, follow-up MR exams were analyzed.

Results

Pure germinoma represented 84/100 cases. Primaries were unifocal pineal (n = 49/100), bifocal pineal and supra-sellar (n = 27/100), isolated supra-sellar (n = 21/100), isolated basal ganglia (n = 2/100) or trifocal pineal, supra-sellar, and basal ganglia (n = 1/100). Metastatic disease occurred in 6/100 patients (depicted by MRI in two and CSF cytology in four). Loco-regional extensions were observed in all patients and classified as follows: third ventricle (n = 88/100), thalamus (n = 47/100), midbrain (n = 42/100), distant sub-ependymal areas (n = 19/100), optic pathways (n = 19/100), lateral ventricles (n = 7/100), cavernous sinus (n = 6/100), corpus callosum (n = 4/100), and fourth ventricle (n = 3/100).

Conclusion

CNS GCT present with specific loco-regional extensions at diagnosis. Improving their recognition will be helpful to further understand their prognostic value and potentially to optimize the treatment.

     

Paracoccidioidomycosis of the central nervous system: CT findings

A retrospective analisis of six cases of central nervous system paracoccidioidomycosis, all but one proven by biopsy and surgery, was carried out to study the CT and clinical data and pathological correlation. Most of the patients were from the country. Headache, vomiting, seizures and hemiparesis were the most frequent symptoms. Papilloedema was present in four patients with raised intracranial pressure. Five patients had chronic lung disease and two with advanced systemic disease, skin and mucous membrane lesions were also observed. The neurological disturbance was sometimes the presenting features and the diagnosis was discovered incidentally after surgery. Both solitary and multiple parenchymal lesions were observed and the cerebral hemispheres were more commonly involved in four patients. Local meningeal involvement was observed in one with a single cortical granuloma. We enphasise the usefulness of CT, showing a rounded or lobulated mass with an isodense or radiolucent centre after contrast enhancement, surrounded by an irregular wall of varying thickness. There was always moderate oedema, extending peripherally. Other infections or neoplastic diseases may present similar findings. Preoperative diagnosis should rest on integration of clinical data, chest films, laboratory and neuroimaging studies.     

Congenital tumors of the central nervous system

Congenital tumors of the central nervous system (CNS) are often arbitrarily divided into “definitely congenital” (present or producing symptoms at birth), “probably congenital” (present or producing symptoms within the first week of life), and “possibly congenital” (present or producing symptoms within the first 6 months of life). They represent less than 2% of all childhood brain tumors. The clinical features of newborns include an enlarged head circumference, associated hydrocephalus, and asymmetric skull growth. At birth, a large head or a tense fontanel is the presenting sign in up to 85% of patients. Neurological symptoms as initial symptoms are comparatively rare. The prenatal diagnosis of congenital CNS tumors, while based on ultrasonography, has significantly benefited from the introduction of prenatal magnetic resonance imaging studies. Teratomas constitute about one third to one half of these tumors and are the most common neonatal brain tumor. They are often immature because of primitive neural elements and, rarely, a component of mixed malignant germ cell tumors. Other tumors include astrocytomas, choroid plexus papilloma, primitive neuroectodermal tumors, atypical teratoid/rhabdoid tumors, and medulloblastomas. Less common histologies include craniopharyngiomas and ependymomas. There is a strong predilection for supratentorial locations, different from tumors of infants and children. Differential diagnoses include spontaneous intracranial hemorrhage that can occur in the presence of coagulation factor deficiency or underlying vascular malformations, and congenital brain malformations, especially giant heterotopia. The prognosis for patients with congenital tumors is generally poor, usually because of the massive size of the tumor. However, tumors can be resected successfully if they are small and favorably located. The most favorable outcomes are achieved with choroid plexus tumors, where aggressive surgical treatment leads to disease-free survival.     

原发性中枢神经系统血管炎的脑血管造影表现

目的评价脑血管造影在诊断或排除原发性中枢神经系统血管炎（PCNSV）中的价值。方法收集并回顾性分析2002年1月至2008年1月于我科行脑血管造影的近1000例脑血管意外（包括脑出血、脑梗死及蛛网膜下腔出血）患者,其中15例脑血管造影结合相应的临床资料诊断为PCNSV,并对其脑血管造影结果进行系统的观察和分析。结果15例患者中共26支脑血管受累,其中包括7支大脑前动脉,12支大脑中动脉,3支椎动脉,1支基底动脉,3支颈内动脉C2C2段。受累血管腔形态改变表现为局限性狭窄（6支）,多发局限性狭窄（3支）,节段性狭窄（6支）,串珠样改变（4支）,闭塞（5支,其中3支伴侧支循环形成）,动脉瘤形成或瘤样改变2支。结论结合患者的临床资料,全脑血管造影是目前诊断或排除PCNSV重要的和可行的一种检查手段,可以指导临床的正确诊断与治疗。     

Imaging findings of central nervous system neuroepithelial cysts

Neuroepithelial cysts are rare and mostly asymptomatic cerebrospinal fluid (CSF)-like cysts. We describe herein the imaging findings in five patients with neuroepithelial cysts. Two cases of proven and three of presumed neuroepithelial cysts are presented. Three of five are located in the thalamus, a location which is not characteristic for neuroepithelial cysts. In the case of incidental finding of asymptomatic neuroepithelial cyst, clinical and radiological follow-up is indicated and surgical intervention is not necessarily warranted. Received 9 June 1997; Revision received 20 August 1997; Accepted 6 October 1997     

Imaging tumors of the pediatric central nervous system

Primary tumors of the central nervous system (CNS) are the second most common neoplasms in children and the leading cause of death in this patient population. The primary objective of this article is to describe the most common pediatric brain tumors and to offer an overview of their respective imaging features, primarily on magnetic resonance imaging. Precise anatomic characterization is essential for developing an appropriate differential diagnosis. Once equipped with this critical information, physicians should be better able to make firm diagnoses, leading to improved disease management and patient outcomes in the setting of CNS tumors of childhood.     

Tuberculosis of the central nervous system: overview of neuroradiological findings

This article presents the range of manifestations of tuberculosis (TB) of the craniospinal axis. Central nervous system (CNS) infection with Mycobacterium tuberculosis occurs either in a diffuse form as basal exudative leptomeningitis or in a localized form as tuberculoma, abscess, or cerebritis. In addition to an extensive review of computed tomography and magnetic resonance features, the pathogenesis and the relevant clinical setting are discussed. Modern imaging is a cornerstone in the early diagnosis of CNS tuberculosis and may prevent unnecessary morbidity and mortality. Contrast-enhanced MR imaging is generally considered as the modality of choice in the detection and assessment of CNS tuberculosis.     

中枢神经系统伸长细胞型室管膜瘤的MR I表现

目的：探讨中枢神经系统伸长细胞型室管膜瘤(TE)的 MRI表现,提高对其病理亚型的进一步认识。方法回顾性分析经手术病理证实的TE 26例,观察肿块发生的部位、大小、内部的信号特点、有无囊变、出血、“帽”征、脊髓空洞、水肿、有无种植转移及增强扫描后的强化特点等。结果26例中,幕上2例均位于左侧额叶,呈大囊小结节结构,与左侧脑室相通,囊内呈均匀脑脊液信号,结节均呈等T1稍短T2信号,增强扫描结节明显强化。椎管内24例,颈段及颈胸段肿瘤16例,1例为囊性肿块,可见出血液-液平面,余均为实性肿块,呈等T1、等或稍长T2信号,4例中心短T2出血信号,囊变常见,6例可见“帽”征,增强后12例边界清晰,大部分中等程度强化,13例有空洞形成,1例有延髓及小脑播散。胸腰段及腰段肿瘤8例,等T1、等或稍长T2信号,其中4例病灶中心有陈旧出血信号,3例病灶边缘小圆形囊变,1例病灶伴空洞,未见“帽”征,增强后呈中等强化。结论脑及脊髓内 TE 的MRI具有一定特征性表现,有助于术前诊断及指导临床治疗。     

颅内原发性中枢神经系统淋巴瘤的MRI表现

目的研究颅内原发性中枢神经系统淋巴瘤（PCNSL）的MR／表现特点。方法回顾性分析8例经手术病理证实的原发性中枢神经系统淋巴瘤的MR／表现。结果8例均为弥漫大B细胞型非霍奇金淋巴瘤。3例为单发,5例为多发,共13个病灶,其中大脑半球8个,基底节区4个,右侧背侧丘脑及基底节区1个。8例病变均表现为局灶性肿块,T1WI呈稍低或等信号;T2WI呈等或稍高信号。增强扫描7例呈明显均匀强化,1例轻度强化。6例瘤周重度水肿,2例瘤周中度水肿。结论原发性中枢神经系统淋巴瘤较为罕见,MRI是诊断该病的重要的无创性检查方法。颅内PCNSL影像学表现多样,但具有一定特征。     

原发中枢神经系统淋巴瘤的颅脑MRI表现

目的:全面分析原发性中枢神经系统淋巴瘤颅脑MRI表现,进一步探讨MRI对该病的诊断价值,以期提高影像学对该病的诊断率。方法:回顾性分析经立体定向活检或开颅手术病理证实的150例原发性中枢神经系统淋巴瘤颅脑MRI表现,男性77例、女性73例,男∶女=1.05∶1,平均年龄53.2（28～87）岁,并复习相关临床及文献资料。结果:150例原发性中枢神经系统淋巴瘤患者中,单发病灶56例（37.3％）,多发病灶94例（62.7％）;幕上皮质下及深部脑白质为好发部位,小脑、脑膜、室管膜也可受累。平扫大部分病灶呈稍长T1、稍长T2信号,增强扫描148例病灶可见强化。增强病灶位于脑实质的93例、可见脑室播散病灶的42例、可见硬脑膜强化的5例、累及柔脑膜的7例、累及神经的1例。结论:原发性中枢神经系统淋巴瘤大多为弥漫性大B细胞淋巴瘤,多发于中老年人,多发病灶多见,MRI表现各有特点,增强扫描表现具有一定特点及规律性。全面了解并掌握MRI表现特点对原发性中枢神经系统淋巴瘤的诊断、鉴别诊断有重要价值,对临床诊治具有重要的指导作用,最终确诊仍需依赖于病理诊断。     

2007年WHO中枢神经系统肿瘤分类变化及新增肿瘤实体的影像学表现

2007年6月出版了第四版.比较2007年WHO中枢神经系统肿瘤分类与2000年旧分类的变化,并概述新增8种肿瘤实体及3种新肿瘤亚型的临床病理学特点及影像学表现.     

2007年WHO中枢神经系统肿瘤分类变化及新增肿瘤实体的影像学表现

2007年6月出版了第四版《WHO中枢神经系统肿瘤分类》。比较2007年WHO中枢神经系统肿瘤分类与2000年旧分类的变化,并概述新增8种肿瘤实体及3种新肿瘤亚型的临床病理学特点及影像学表现。     

Early CT findings of global central nervous system hypoperfusion

Fifty-seven patients (34 men and 23 women) underwent percutaneous angioplasty (PTA) of the superficial femoral artery. Follow-up angiography revealed restenoses/reocclusions in 23 patients (relapsing group) and a patent, previously-dilated segment in 34 cases (patent group). These two groups were compared retrospectively regarding their clinical and angiographic state at the time of PTA. The lengths and types of the dilated arterial lesions were similar for both groups. However, the patients in the relapsing group were older as an average, showed significantly more advanced arteriosclerotic disease of their outflow tracts, and were predominantly female. For the relapsing group, a smaller lumen had been attained and a significantly higher brachiopedal pressure difference remained after PTA as opposed to the patients of the patent group. Of the patients with clinical signs of relapse, 28% still had patency of previously dilated segments at follow-up angiography. The true patency rate of dilated arterial segments presumably is higher than what is expected from follow-up examinations using clinical methods alone.     

中枢神经系统肠源性囊肿的MRI表现

目的:探讨中枢神经系统肠源性囊肿的MRI表现.方法:搜集经手术及病理最终确诊的23例肠源性囊肿患者并分析其MRI表现,所有患者均经MRI平扫,其中10例行MRI增强扫描,4例行DWI扫描.结果:23例肠源性囊肿患者中,3例发生在颅内,其中2例发生在左侧中颅窝,1例发生在桥前池,其余20例发生在椎管并且全部位于髓外硬膜下,其中颈段10例,胸段8例,腰段2例.MRI平扫大部分病灶T1WI呈等低信号,T2 WI呈高信号,部分病灶信号混杂;9例增强扫描囊液及囊壁均未见明确强化,1例见边缘强化;部分病例可见特征性“脊髓嵌入征”表现;DWI均未见明显扩散受限;2例伴脊椎发育异常.结论:肠源性囊肿的形态及MRI信号特点具有一定特征,结合临床症状、伴发体征有助于早期诊断.     

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。     

婴儿先天性梅毒中枢神经系统的CT表现

目的 探讨先天性梅毒婴儿的中枢神经系统CT特征。方法 回顾性分析经临床确诊的11例先天性梅毒婴儿的中枢神经系统CT资料。结果 10例新生儿患者在CT上均表现为脑白质的弥漫性密度减低，其中3例合并有蛛网膜下腔出血，1例合并有脑内出血。1例2个月大的患儿表现为两侧额、颞叶脑沟增宽及大脑镰前部蛛网膜下腔增宽，5例经治疗后45d至6个月，CT复查表现为两侧脑沟、脑池、脑裂的增宽，其中3例伴有侧脑室和第3脑室的扩大。结论 先天性梅毒中枢神经系统的CT表现在新生儿类似重度缺氧缺血性脑病，随访复查可呈现外部性脑积水或脑发育不良的表现。