桥小脑角区肿瘤的MRI诊断

目的：分析桥小脑角区肿瘤的ＭＲＩ 表现,提高桥小脑角区肿瘤的ＭＲＩ 诊断准确率。材料和方法：搜集一组经手术及病理证实的桥小脑角区肿瘤４５ 例,全部行ＭＲＩ 平扫及增强检查。结果：本组４５ 例中听神经瘤１８ 例,脑膜瘤８ 例,三叉神经瘤６ 例,胆脂瘤３ 例,血管母细胞瘤４ 例,海绵状血管瘤４ 例,脊索瘤２ 例。肿瘤位于左侧桥小脑角区占６９ ％ ,位于右侧桥小脑角区占３１ ％ 。８７ ％ 的肿瘤呈园形或类园形,轮廓较清晰,占位效应明显,在Ｔ１ ＷＩ上多呈低等信号,Ｔ２ ＷＩ 上多呈高信号,增强后呈明显均匀强化。但各种肿瘤又有其特征性ＭＲ 改变,如三叉神经瘤跨中后颅窝生长,胆脂瘤沿脑池生长,听神经溜,三叉神经瘤,血管母细胞瘤多见囊变、坏死,海绵状血管瘤多见出血,脑膜瘤、脊索瘤有不规则钙化,多数脑膜瘤增强后见脑膜尾征。ＭＲＩ 对桥小脑角区肿瘤的检出率、定位率、定性率分别为１００ ％ 、１００ ％ 、９０ ％ 。结论：ＭＲＩ 对桥小脑角区肿瘤的诊断及鉴别诊断有重要价值。     

桥小脑角区肿瘤及肿瘤样病变的CT诊断

目的：探讨CT对桥小脑角区肿瘤及肿瘤样病变的诊断价值。方法：回顾性分析经手术病理证实的桥脑小脑角区肿瘤及肿瘤样病变的CT特征。其中听神经瘤9例、胆脂瘤4例、脑膜瘤3例、耳源性脑脓肿5例、三叉神经瘤1例。结果：各种肿瘤的CT特征，随其种类而不同，如听神经瘤均位于内听道开口处，呈等或低密度团块，轻度均匀或环状强化。胆脂瘤呈球形或扁平形，球形位于硬膜外，密度不均，壁有钙化。扁平形位于蛛网膜下腔， 边缘清楚，均匀低密度。脑膜瘤均具有典型脑膜瘤特征，明显强化。耳源性脑脓肿周边有明显水肿、囊壁清晰，囊内呈均匀低密度。三叉神经瘤跨中后颅窝伴岩锥尖骨质破坏。结论：桥脑小脑角区肿瘤各具特点，CT能提供明确诊断。     

桥小脑角区肿瘤的MRI诊断

目的探讨桥小脑角区肿瘤的MRI表现及特征,提高对桥小脑角区肿瘤的定性诊断水平。方法34例经手术和病理证实的桥小脑角区肿瘤,其中听神经瘤20例,脑膜瘤4例,三叉神经瘤3例,血管母细胞瘤2例,胆脂瘤、蛛网膜囊肿、动脉瘤、胶质瘤及转移瘤各1例。在静注Gd-DTPA前后均经SE,FSE序列磁共振成像。结果听神经瘤,脑膜瘤,三叉神经瘤为桥小脑角区最常见的肿瘤,该区肿瘤大部分有特征性MRI表现,术前定位、定性准确率分别为96.9%,94.1%。结论MRI在桥小脑角区肿瘤影像诊断中具有不可比拟的优势,可作为桥小脑角区肿瘤术前的首选检查方法。     

桥小脑角区肿瘤的磁共振成像诊断

目的：探讨桥小脑角区肿瘤的磁共振成像（MRI）的影像学表现及鉴别诊断,以提高其诊断水平。方法总结分析经影像学及手术病理证实的桥小脑角区肿瘤共33例。其中听神经瘤14例,三叉神经瘤8例,脑膜瘤2例,胆脂瘤3例,蛛网膜囊肿4例,恶性肉芽肿1例,颈静脉球瘤1例。所有患者均行MRI平扫及增强扫描,部分病例结合CT扫描。总结分析肿瘤的形态、大小、生长方式、信号特征及强化方式。结果桥小脑角区的肿瘤以听神经瘤占首位,其次为三叉神经瘤、胆脂瘤、蛛网膜囊肿、脑膜瘤。还有一些少见的肿瘤,诸如恶性肉芽肿、颈静脉球瘤等。结论桥小脑角区肿瘤MRI表现各具有不同特性,了解这些特征有助于诊断及鉴别诊断,为临床治疗及手术提供依据。     

桥小脑角区肿瘤的MRI诊断和鉴别诊断

目的 :探讨桥小脑角区肿瘤MRI的表现及特征。材料和方法 :分析 193例资料完整 ,均经手术和病理证实的桥小脑角区肿瘤 ,其中听神经瘤 135例 ,三叉神经瘤为 30例 ,脑膜瘤 12例 ,胆脂瘤 4例 ,蛛网膜囊肿 2例 ,动脉瘤 1例 ,血管母细胞瘤 4例 ,脉络丛乳头状瘤 3例 ,海绵状血管瘤 1例 ,转移瘤 1例。结果 :桥小脑角区肿瘤中 ,脑外肿瘤 95 .3% ,脑内肿瘤 4.7% ;良性肿瘤占 98.4% ,恶性肿瘤占 1.6%。发生于桥小脑角区的前三位肿瘤分别为听神经瘤 69.9% ,三叉神经瘤 15 .5 % ,脑膜瘤 6.2 % ,该区肿瘤大部分有特征性MRI表现 ,术前定位、定性诊断准确率分别为 10 0 %、96.4%。结论 :MRI是检查桥小角区肿瘤的首选方法 ,对桥小脑角区肿瘤诊断和鉴别有重要价值     

CT在三叉神经痛和半侧面肌痉挛诊断中的应用价值

目的:探讨CT在诊断三叉神经痛与半侧面肌痉挛中的价值。方法:将772例经手术治疗的三叉神经痛(326例)与半侧面肌痉挛(446例)患者的术前CT资料与手术结果进行对照分析。结果:①CT表现:772例患者中,CT发现患侧桥小脑角胆脂瘤26例,听神经瘤14例,三叉神经瘤8例,脑膜瘤6例,患侧桥小脑角扩张增粗血管490例(63.47%),CT未见异常者228例(29.6%);②手术病理结果:胆脂瘤27例,听神经瘤14例,三叉神经瘤8例,脑膜瘤6例,三叉神经或面神经根部异常血管压迫者696例(90.15%),术中未见异常者21例。结论:CT在病因诊断方面很有帮助,它既可以发现桥小脑角占位病变,又能显示桥小脑角扩张增粗的血管,是术前有效的检查方法。     

桥小脑角区肿瘤的MRI诊断

目的：探讨桥小脑角区肿瘤MRI的表现及特征。材料和方法：分析297例资料完整、均经手术和病理证实的桥脑角区肿瘤。其中听神经瘤184例，三叉神经瘤39例，脑膜瘤27例，胆脂瘤13例，蛛网膜囊肿4例，动脉瘤1例，血管母细胞瘤6例，脉络丛乳头状瘤3例，海绵状血管瘤5例，转移瘤3例，脊索瘤3例。结果 桥小脑角区肿瘤中，脑外肿瘤93．8％，脑内肿瘤6．2％，发生于桥小脑角区的前三位肿瘤分别为听神经瘤63．6％，三叉神经瘤13．3％，脑膜瘤9．2％。该区肿瘤大部分具有特征性MRI表现。术前定位定性诊断准确率分别为100％、96．4％。结论：MRI是检查桥脑角区肿瘤的首选方法，对桥小脑角区肿瘤诊断和鉴别诊断有重要价值。     

桥小脑角区肿瘤的MRI诊断和鉴别诊断

目的：分析桥小脑角区肿瘤的MRI表现和特征，提高桥小脑角区肿瘤的MRI诊断准确率。材料和方法：收集临床资料完整、经手术和病理证实的桥小脑角区肿瘤36例，全部行MRI平扫及增强检查。结果：听神经瘤16例，三叉神经瘤7例，脑膜瘤6例，胆脂瘤4例，蛛网膜囊肿2例，血管母细胞瘤1例。桥小脑角区肿瘤大部分有其特征性表现。结论：MRI对桥小脑角区肿瘤的诊断和鉴别诊断具有重要价值。     

MRI在三叉神经痛和半侧面肌痉挛病因诊断中的价值

目的 探讨MRI在诊断三叉神经痛与半侧面肌痉挛中的价值.方法 将51例三叉神经痛与23例半侧面肌痉挛患者的术前MRI资料与手术结果进行对照分析.结果 ①74例患者中,MRI诊断患侧桥小脑角胆脂瘤8例,听神经瘤7例,三叉神经瘤4例,脑膜瘤3例,患侧神经微血管压迫49例(66.21％),MRI未见异常者3例(4.05％);②手术病理结果:胆脂瘤8例,听神经瘤7例,三叉神经瘤4例,脑膜瘤3例,三叉神经或面神经根部异常血管压迫者46例(62.16％),术中未见异常者6例(8.11％).结论 MRI在三叉神经痛和半侧面肌痉挛病因诊断中具有很高价值,是术前首选的检查方法.     

听神经瘤的CT诊断

作者分析了75例(其中4例为双侧性)经病理证实的78个听神经瘤的CT表现及与26例其它桥小脑角区(CPA)脑外肿瘤(脑膜瘤12、胆脂瘤11、三叉神经瘤2和脊索瘤1)的鉴别诊断。所有病人都作了增强前、后CT扫描;对24例可疑听神经瘤者作了脑池气造影CT(gcs-CTC),1例为内耳道内神经瘤,其余正常;5例可疑者作了甲泛醣胺脑池造影CT(M-CTC),1例诊断听神经瘤,其余正常。作者见到,93.6％的听神经瘤增强前CT表现为等或低密度,增强后53.8％均一强化,强化类型与增强前密度有内在关系。肿瘤中心多位于内耳道平而,多呈圆形(76.9％),与岩骨间夹角     

MRI in acoustic neuroma: a review of 35 patients

Summary This retrospective study is aimed to assess the diagnostic efficacy of MRI in relation to contrast enhanced CT and air-CT-cisternography. MRI examinations were performed in 35 patients with suspected neurosensorial damage and suggestive of acoustic neuroma: 27 presented on MRI with unilateral tumors, 3 patients had a bilateral tumor and 5 patients were negative on all imaging modalities. The total number of acoustic neuromas detected was therefore 33. To date microscopic analysis has been performed on 12 tumors and histological data based on type Antoni A and Antoni B classification is available. Contrast enhanced CT detected 19 tumors, yielding an overall sensitivity rate of 58%. Air-CT cisternography identified an additional 5 tumors with a sensitivity rate of 100%. MRI identified 33 acoustic neuromas in 30 patients and was negative in 5 patients (sensitivity and accuracy 100%). Considering sensitivity in relation to location, MRI was much better than contrast enhanced CT for internal auditory canal (IAC) tumors (100% versus 36%) and better for cerebello-pontine angle tumors (CPA) tumors (100% versus 68%). The evolution of MRI technique, the various pulse sequences used and their actual selection is discussed. Seven patients received a paramagnetic contrast agent (Gadolinium-DTPA) with the additional benefit of a better demonstration of the tumor. The results suggest that MRI is the best non invasive technique for demonstrating acoustic neuromas.     

颈静脉孔区肿瘤的CT和MRI诊断

目的：探讨CT和MRI对颈静脉孔区肿瘤的诊断及鉴别诊断。方法：回顾性分析了经手术病理证实的34例颈静脉孔区肿瘤的CT和MR影像资料,其中包括颈静脉球瘤12例,神经鞘瘤10例,转移瘤3例,脑膜瘤2例,神经纤维瘤、脊索瘤、软骨瘤、软骨肉瘤、纤维脂肪瘤、纤维血管瘤和先天性囊肿各1例。CT检查21例,其中15例作增强扫描。MRI检查31例,其中24例加作MR增强扫描。结果：肿瘤内纡曲流空的血管即“椒-盐”征是颈静脉球瘤的特征性MRI表现。神经鞘瘤易发生囊变,注射对比剂后肿瘤中度强化。转移瘤骨质破坏不规则。脑膜瘤增强扫描可见脑膜“尾巴”征。软骨瘤和软骨肉瘤可见明显钙化。结论：CT与MRI相结合能更全面地为临床提供诊断、鉴别诊断及治疗所需要的信息,为治疗方法的选择提供可靠的依据。     

后颅窝肿瘤的影像诊断和鉴别诊断

目的：总结分析38例后颅窝肿瘤的CT或MRI特征,提高对后颅窝肿瘤的诊断和鉴别诊断水平。方法：38例肿瘤中34例经手术病理证实,4例经临床影像诊断。所有患者均行CT平扫和增强扫描,其中8例行MR检查。结果：听神经瘤9例,脑膜瘤5例,Ⅰ级星形细胞瘤2例,Ⅱ－Ⅲ级星形细胞瘤4例,少枝胶质细胞瘤1例,血管母细胞瘤3例,室管膜瘤、髓母细胞瘤、三叉神经瘤、单发脑转移瘤各2例,胆脂瘤及蛛网膜囊肿各1例,以上均为手术病理证实;经临床影像诊断转移瘤4例。结论：后颅窝瘤有其好发部位,CT和MRI可清晰显示后颅窝肿瘤的不同特点。     

Differentiation of cerebellopontine angle neuromas and meningiomas with MR imaging

Postcontrast CT of the temporal bone is the neuroradiological study of choice for investigation of cerebellopontine angle (CPA) and internal auditory canal (IAC) lesions. Nonenhancing or small lesions may need CT combined with air or metrizamide cisternography for their detection. Magnetic resonance (MR) imaging has shown interesting capabilities as a noninvasive study for the visualization of the IAC, the neural bundle entering the canal, the brain stem, and cerebellum. In the present series of 24 cases, MR imaging detected the lesion in all 11 verified tumors. We feel that MR can replace invasive air and metrizamide cisternography in the diagnosis of CPA lesions and can help in the differentiation between acoustic neuromas and meningiomas.     

Unusual lesions of the cerebellopontine angle: a segmental approach.

Tumors of the cerebellopontine angle (CPA) are frequent; acoustic neuromas and meningiomas represent the great majority of such tumors. However, a large variety of unusual lesions can also be encountered in the CPA. The site of origin is the main factor in making a preoperative diagnosis for an unusual lesion of the CPA. In addition, it is essential to analyze attenuation at computed tomography (CT), signal intensity at magnetic resonance (MR) imaging, enhancement, shape and margins, extent, mass effect, and adjacent bone reaction. CPA masses can primarily arise from the cerebellopontine cistern and other CPA structures (arachnoid cyst, nonacoustic schwannoma, aneurysm, melanoma, miscellaneous meningeal lesions) or from embryologic remnants (epidermoid cyst, dermoid cyst, lipoma). Tumors can also invade the CPA by extension from the petrous bone or skull base (cholesterol granuloma, paraganglioma, chondromatous tumors, chordoma, endolymphatic sac tumor, pituitary adenoma, apex petrositis). Finally, CPA lesions can be secondary to an exophytic brainstem or ventricular tumor (glioma, choroid plexus papilloma, lymphoma, hemangioblastoma, ependymoma, medulloblastoma, dysembryoplastic neuroepithelial tumor). A close association between CT and MR imaging findings is very helpful in establishing the preoperative diagnosis for unusual lesions of the CPA.     

Magnetic resonance findings in 92 acoustic neuromas.

A retrospective analysis of the MR findings in 92 cases of acoustic neuromas is presented. The method of examination included in all cases intravenous injection of Gadolinium (Gd-DTPA or DOTA) with realization of sections in the axial and coronal planes. In 21 cases native MR studies were performed in the axial plane, before Gadolinium injection, with T1WI (n = 21), and T2WI (n = 6) images. Tumors were strictly intracanalar in 19 cases (20.7%), only localized in the cerebellopontine angle (CPA) in 5 cases (5.4%), and in 68 cases (73.9%) the tumors had intra- and extracanalar components. In this last group of lesions, 63.2% completely filled the internal auditory canal (IAC), and 36.8% occupied the internal portion of the IAC. In most cases (85.3%) the mean diameter of the CPA component was less than or equal to 2.5 cm. Lesions were more frequently homogeneous (58.8%) after Gd i.v.-enhancement. Heterogeneity was noted mainly in large lesions (greater than 2.5 cm: 100%). In all cases but one, the tumors were round, or oval-shaped, well-delineated, and did not present significant contact with the petrous bone. In 80.9% of CPA lesions, the center of the tumor was posteriorly excentered in relation to the internal auditory canal, whereas it was centered in 16.2% of cases. Widening of the IAC was observed in 51.1% of cases. In 45.2% of tumors of the CPA, smoothing of the posterior edge of the porus was visible.     

筛窦脑膜瘤影像诊断误诊病例分析

目的：探讨筛窦脑膜瘤的影像学表现。方法：回顾分析经手术病理证实的6例筛窦脑膜瘤平片、CT及MRI表现。结果：CT表现：3例呈巨大囊性肿块;2例呈巨大囊、实性肿块;1例呈巨大实质性肿块;囊性部分囊壁周围骨质硬化;实性部分密度均匀或不均匀,可有钙化和囊变区,明显增强。MRI表现（1例）：囊、实性肿块,囊性部分T1WI低信号,T2WI高信号;实性部分T1WI与T2WI均为等信号,有增强。平片表现（3例）：均见筛窦密度增高,体积变大,窦壁光整。结论：筛窦脑膜瘤CT表现颇具特征性;MRI对鉴别诊断有帮助;平片定性诊断较困难。     

国产钆喷酸葡胺在脑肿瘤诊断中的作用

目的：探讨国产钆喷酸葡胺在脑肿瘤诊断中的价值。材料和方法：回顾分析８２例脑肿瘤的ＭＲＩ增强表现,其中脑胶质细胞瘤２８例;脑膜瘤１３例;垂体微腺瘤１６例;脑转移瘤１５例;颅咽管瘤２例;松果体瘤２例;三叉神经瘤２例;听神经瘤３例;颅底脊索瘤１例。结果：８２例脑肿瘤病人注射造影剂后,有轻度强化９例,中度强化２９例,明显强化２３例,增强效果达７４．４％,其中脑膜瘤、胶质细胞瘤、脊索瘤强化明显;垂体微腺瘤不强化,而正常垂体组织强化明显,从而把肿瘤组织勾描清楚,与ＣＴ的增强表现相类似。增强病例中有轻微反应３例。结论：国产钆喷酸葡胺在脑肿瘤诊断中是一种较为理想的造影剂     

MRI 在脊索样脑膜瘤诊断及与其他脑膜瘤鉴别诊断中的价值

目的：探讨脊索样脑膜瘤(CM)的 MRI 特征性表现,并与其他脑膜瘤相鉴别。方法回顾性分析经手术病理确诊的7例 CM 患者的临床及 MRI 资料,定性分析其 MRI 各序列的信号特征,并进一步定量分析肿瘤各序列的标准化信号强度比,包括标准化 T1 WI 信号强度比(NT1)、标准化 T2 WI 信号强度比(NT2),标准化表观扩散系数比(NADC)、标准化 T1增强信号强度比(NCE)。采用 Fisher 精确检验和 Dunnett T 3检验法与经病理证实的非脊索样脑膜瘤(34例Ⅰ级脑膜瘤、16例非脊索样Ⅱ级脑膜瘤、5例Ⅲ级脑膜瘤)进行比较。结果CM 在 T2 WI 序列上均表现为高信号,非脊索样脑膜瘤则表现为等、低或稍高信号;CM 在扩散加权成像(DWI)上信号多变,但均无明显扩散受限,表观扩散系数(ADC)图上表现为高信号,增强扫描后实性部分明显强化。CM 的定量指标 NT2、NADC 及 NCE 均高于其他脑膜瘤(P 均<0.01),而 NT1无明显统计学差异(P =0.889)。病灶内有无囊变坏死、T2 WI 是否可见“流空效应”、瘤周水肿程度、是否出现脑膜尾征及宽基底对鉴别 CM 和其他脑膜瘤意义不大。结论CM 的MRI 表现有一定特征性,T2 WI 多表现为高信号,扩散不受限,强化程度更明显,NT2、NADC 及 NCE 的测定有助于提高其术前诊断的准确性。