血管瘤型脑膜瘤MRI诊断价值

目的比较WHOⅠ级不同亚型脑膜瘤MRI表现,探讨血管瘤型脑膜瘤影像特点,提高诊断水平。方法分析经病理确诊的93例WHO I级不同亚型脑膜瘤MRI图像资料,定性分析各序列的信号特征,定量分析标准化信号强度比值NT1、NT2、NADC及强化幅度。采用Fisher确切概率法和DunnettT3检验法比较血管瘤型与WHOⅠ级其他亚型脑膜瘤有无统计学差异,P0.005有统计学意义。结果血管瘤型与其他亚型脑膜瘤定性参数囊变坏死、血管流空及瘤周水肿,脑膜尾征与定量参数NADC及强化幅度之间有统计学差异(P均0.005),而分叶征、瘤脑界面及NT1、NT2无明显统计学差异。结论血管瘤型脑膜瘤的MRI表现有一定特征,ADC值及强化幅度的测定有助于提高其术前诊断的准确性。     

MRI在鞍旁海绵状血管瘤与脑膜瘤鉴别诊断中的应用

目的 分析MRI在鉴别鞍旁海绵状血管瘤与脑膜瘤的表现特点.方法 回顾性分析经手术病理证实的20例鞍旁肿瘤MRI影像表现,观察MR影像特征.结果 鞍旁海绵状血管瘤与脑膜瘤均可同时侵犯鞍内及鞍旁,但两者MRI信号有特征性,海绵状血管瘤T1WI呈等或稍低于脑灰质信号,T2WI信号强度类似脑脊液信号,增强扫描病变强化显著,可见延迟强化.脑膜瘤呈等T1、T2信号,T2WI信号强度与脑灰质信号近似,增强扫描病变呈中等度弥漫性强化,相应部位可见脑膜线样强化.结论 MRI平扫加增强能明确显示鞍旁海绵状血管瘤及脑膜瘤的不同信号改变、强化特点及内部结构特点,其MRI信号特点对诊断有价值.     

脊索瘤的影像学诊断和鉴别诊断

目的探讨脊索瘤的影像学表现。方法收集经手术病理证实的脊索瘤14例,其中行磁共振成像(MRI)12例,CT 3例,1例行CT+MRI,对其影像学表现进行回顾性分析。结果 14例脊索瘤中,发生在颅底5例(36%),骶尾部9例(64%)。CT表现肿瘤为等或稍高密度,常见斑片样或斑点状钙化,骨质破坏以溶骨性常见;MRI表现为T1WI呈低、等、高混杂信号,T2WI则以高、低混杂信号为主。增强后病灶呈中到重度强化,强化信号不均匀。结论脊索瘤的CT和MRI表现有一定的特征性,结合临床大多可以确诊;MRI表现较具特征性,对脊索瘤的位置、形态、浸润范围与周围组织的解剖关系优于CT。     

脑室内脑膜瘤的MRI诊断与鉴别诊断

目的探讨脑室内脑膜瘤MRI表现及与其它脑室内肿瘤的鉴别诊断,以提高对该病的诊断准确性。方法对经手术病理证实的12例脑室内脑膜瘤MRI表现进行回顾性分析。结果脑室内脑膜瘤好发于侧脑室(10例),次为三脑室(1例)和四脑室(1例),多表现为圆形、类圆形(8例)或分叶状(4例)肿块。T1WI呈稍低信号(10例)或等信号(2例),T2WI呈稍高信号(9例)或等信号3例),7例见不同程度的瘤周水肿。增强扫描多明显均匀强化(9例),3例见斑片状低信号。结论脑室内脑膜瘤的MRI表现具有一定的特征性,结合临床资料可提高其诊断准确性。     

侧脑室内脑膜瘤的MRI诊断与鉴别诊断

目的 探讨侧脑室内脑膜瘤的MRI表现及与其它脑室内肿瘤的鉴别诊断。方法 对经手术病理证实的6例侧脑室内脑膜瘤的临床、病理及MRI资料进行回顾性分析。结果 本组术前MRI诊断定位正确率为100％，定性正确率为66．7％(4／6)。其MRI特征性表现为：(1)肿瘤呈类圆形，边界清楚，在T1WI上为等低信号，T2WI为等高信号。(2)侧脑室扩大不明显，脑积水程度较轻。(3)增强后，均存在中至高度强化。结论 侧脑室内脑膜瘤的MRI表现有一定的特征性，其病理基础是在胚胎发育形成脉络丛及血管膜的过程中，部分蛛网膜被带入脑室后发展而来；MRI可以对其进行诊断并和脑室内的其它肿瘤进行鉴别。     

脑膜瘤的MRI表现与组织病理对照研究

目的　研究脑膜瘤的磁共振表现与其病理分类之间的关系。方法　回顾分析 12 8例经手术病理证实为脑膜瘤患者的MRI表现。结果　T1WI图像 ,上皮型脑膜瘤 2 9例 ( 4 9% )呈低信号 ,11例 ( 19% )呈稍低信号 ,17例 ( 2 9% )呈等信号。而纤维型脑膜瘤T1WI信号类型分别为 2 3例 ( 5 9% ) ,5例 ( 13 % )和 9例 ( 2 3 % )。在T2 WI图像上 ,3 4例 ( 5 8% )上皮型脑膜瘤呈高信号 ,15例 ( 2 5 % )呈稍高信号 ,10例 ( 17% )呈等信号 ,而纤维型分别为 2例 ( 5 % ) ,8例 ( 2 0 .5 % )和 11例 ( 2 8% )。上皮型、纤维型、移行型在T1WI上均呈现等、低信号 ,而在T2 WI图像上 ,上皮型、血管瘤型及移行型呈现为高信号或稍高信号 ;纤维型脑膜瘤T1WI以低或稍低信号为主。结论　在MRIT1WI图像上 ,各组织学类型之间信号强度的分布无显著性差别 ,而在T2 WI上 ,信号强度与病理类型具有统计学的相关性     

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。     

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。     

磁共振常规成像及DWI对脑膜瘤的诊断价值

目的:比较磁共振常规成像序列(T1WI、T2WI及FLAIR)与DWI对脑膜瘤的检出率,探讨其鉴别病理亚型及良恶性的价值。方法:回顾性分析70例经手术病理证实的脑膜瘤患者的MRI图像,计算不同序列对脑膜瘤的检出率;测量并比较不同病理亚型、不同病理分级的肿瘤实质的平均ADC值和相对ADC值(rADC值)。结果:在T2WI上出现低信号的多是纤维型、过渡型和砂粒体型,出现高信号的多是脑膜上皮型和血管瘤型。在各个序列中,以DWI对脑膜瘤病变的检出率最高(87.1%),T2WI次之(74.3%),T1WI最低(38.6%)。恶性脑膜瘤的囊变发生率(67%)明显高于良性脑膜瘤(22%)。良性组各亚型间、良恶性两组间平均ADC值及rADC值差异均无统计学意义(P>0.05)。结论:DWI可提高对脑膜瘤的检出率,但单独根据ADC值并不能鉴别脑膜瘤的亚型及良恶性。DWI结合常规MRI表现对脑膜瘤亚型及良恶性的鉴别有一定意义。     

侧脑室内脑膜瘤的CT和MRI诊断

目的分析侧脑室内脑膜瘤的CT和MRI表现,以提高诊断准确性。方法回顾性分析8例手术病理证实的侧脑室内脑膜瘤的CT和MRI资料。结果肿瘤呈圆形或分叶状软组织肿块,CT平扫多呈稍高或高密度,MRI多表现为T1WI等信号、T2WI等高信号,除1例因肿瘤坏死致信号和强化不均匀外,余7例肿瘤密度、信号及强化较均匀;周围脑组织可见不同程度水肿。1例肿瘤稍向周围脑组织呈浸润性生长,病理诊断为恶性脑膜瘤。结论侧脑室内脑膜瘤的CT、MRI表现具有一定的特征性,结合临床资料可提高诊断准确性。     

Chordoid Meningioma: Differentiating a Rare World Health Organization Grade II Tumor from Other Meningioma Histologic Subtypes Using MRI

BACKGROUND AND PURPOSE:Meningiomas are very commonly diagnosed intracranial primary neoplasms, of which the chordoid subtype is seldom encountered. Our aim was to retrospectively review preoperative MR imaging of intracranial chordoid meningiomas, a rare WHO grade II variant, in an effort to determine if there exist distinguishing MR imaging characteristics that can aid in differentiating this atypical variety from other meningioma subtypes.MATERIALS AND METHODS:Ten cases of WHO grade II chordoid meningioma were diagnosed at our institution over an 11-year span, 8 of which had preoperative MR imaging available for review and were included in our analysis. Chordoid meningioma MR imaging characteristics, including ADC values and normalized ADC ratios, were compared with those of 80 consecutive cases of WHO grade I meningioma, 21 consecutive cases of nonchordoid WHO grade II meningioma, and 1 case of WHO grade III meningioma.RESULTS:Preoperative MR imaging revealed no significant differences in size, location, signal characteristics, or contrast enhancement between chordoid meningiomas and other meningiomas. There were, however, clear differences in the ADC values and normalized ADC ratios, with a mean absolute ADC value of 1.62 ± 0.33 × 10⁻³ mm²/s and a mean normalized ADC ratio of 2.22 ± 0.47 × 10⁻³ mm²/s in chordoid meningiomas compared with mean ADC and normalized ADC values, respectively, of 0.88 ± 0.13 × 10⁻³ mm²/s and 1.17 ± 0.16 × 10⁻³ mm²/s in benign WHO grade I meningiomas, 0.84 ± 0.11 × 10⁻³ mm²/s and 1.11 ± 0.15 × 10⁻³ mm²/s in nonchordoid WHO grade II meningiomas, and 0.57 × 10⁻³ mm²/s and 0.75 × 10⁻³ mm²/s in the 1 WHO grade III meningioma.CONCLUSIONS:Chordoid meningiomas have statistically significant elevations of ADC and normalized ADC values when compared with all other WHO grade I, II, and III subtypes, which enables reliable preoperative prediction of this atypical histopathologic diagnosis.

Meningiomas are the second most common primary intracranial neoplasm, constituting approximately 13%–25% of such tumors.¹ There are 15 variants of meningioma according the 2007 World Health Organization (WHO) classification of tumors of the central nervous system.² Although 80%–90% of meningiomas are classified as benign WHO grade I tumors, WHO grade II and III varieties demonstrate a more aggressive clinical course and have a greater propensity for recurrence, and the grade and extent of original resection accounts for these differences.³ Ideally, preoperative imaging to identify the potentially more aggressive grade II and III varieties would be helpful for presurgical planning and subsequent imaging follow-up. One such rare variant is the WHO grade II chordoid meningioma. A little more than 100 cases of chordoid meningioma have been described in the English-language literature, the majority of which are in the pathology and neurosurgery literature.^4–9Attempts to distinguish benign from atypical and malignant meningiomas have been undertaken with variable results, and DWI and ADC values have provided the most reliable means of differentiation,^10,11 though no data analysis specifically examining the chordoid morphologic variant has been performed. To the best of our knowledge, only 3 case reports in which the MR imaging characteristics of chordoid meningiomas were described have been published in the radiology literature.^12–14We compared 8 cases of intracranial chordoid meningioma to 80 consecutive cases of WHO grade I meningioma, 21 consecutive cases of nonchordoid WHO grade II meningioma, and 1 WHO grade III meningioma in an effort to determine if there exist distinguishing MR imaging characteristics that can aid in differentiating this particular subtype.     

脑膜瘤伴瘤周水肿的MRI特征分析

目的:探讨脑膜瘤伴瘤周水肿的机制。方法:49例经手术病理证实的脑膜瘤,回顾性分析伴有瘤周水肿脑膜瘤的MRI特征,用Fisher′s检验比较肿瘤大小、部位、边缘、假包膜征及肿瘤T2WI信号与瘤周水肿发生的关系。结果:肿瘤边缘、假包膜征和肿瘤T2WI信号与脑膜瘤瘤周水肿发生明显相关,P值分别是0.016,0.004 和0.041。结论:脑膜瘤脑界面侵袭性模式和T2WI高信号是提示脑膜瘤发生瘤周水肿的因素。     

Meningiomas with brain edema: radiological characteristics on MRI and review of the literature

OBJECT: Despite their benign characteristics, meningiomas are often accompanied by perifocal brain edema. The aims of this study are to determine what kind of characteristics on magnetic resonance (MR) image are indicative of a meningioma that produces brain edema and to investigate the mechanism responsible for brain edema accompanying meningiomas. METHODS: Fifty-one patients with meningioma were examined by magnetic resonance imaging (MRI), and tumor size, tumor location, shape of tumor margin, peritumoral rim, and signal intensity of tumor on T2-weighted image (T2WI) were compared and correlated with the presence versus absence of brain edema. Surgical histopathology was also examined and correlated with the MRI findings and brain edema. RESULTS: Shape of tumor margin, peritumoral rim, and signal intensity of tumor on T2WI correlated with brain edema on multivariate analyses. CONCLUSION: Invasive pattern of brain-tumor interface and hyperintensity on T2WI were indicative factors of meningiomas producing brain edema.     

脑膜瘤MR信号特征在诊治中的价值

目的:探讨脑膜瘤的MRI表现与病理学类型、瘤体质地之间的关系。方法:收集术前行MRI检查并经手术病理证实的63例脑膜瘤患者,将其MR信号特征与病理学类型及其瘤体质地的关系进行对照研究分析。结果:5例血管瘤脑膜瘤表现最典型,在T1WI上呈低或稍低信号,在T2WI上呈高信号,质地软。上皮型、纤维型、过渡型二种脑膜瘤在T2WI上有一定的特征性,22例纤维型脑膜瘤17例(77.3%)呈现为低及稍低信号,质地硬,17例上皮型脑膜瘤11例(64.7%)呈现为等信号,质地较硬,过渡型脑膜瘤介于其两者之间。结论:脑膜瘤的T2WI信号特征可在一定程度上反应脑膜瘤病理学类型及瘤体的质地,对指导神经外科医生的制定治疗万案具有重要的参考价值。     

脑(脊)膜瘤MRI表现与病理分型的相关性研究

目的 探讨脑（脊）膜瘤MRI表现与病理分型的关系。资料与方法 搜集有病理分型的脑（脊）膜瘤37例。纤维型10例,上皮型13例,血管瘤型3例,血管外皮型3例,非典型2例,砂粒型2例,过渡型2例,血管母细胞型1例,间变型1例。回顾性分析其MRI特点。结果 纤维型：T2研肿瘤中央明显极低信号,周边为等信号,增强扫描周边明显强化,病灶内T2研极低信号区轻度强化;上皮型：肿瘤与皮质等信号,信号欠均匀,增强扫描明显强化;颅内血管瘤型、血管母细胞型及血管外皮型呈长TI长T2信号,血管母细胞型及血管外皮型可出现周围大范围水肿,增强后非常明显强化。过渡型表现可类似其某单一类型。非典型及间变型可信号不均匀、囊变、出血,间变型周围明显水肿。结论 不同类型脑（脊）膜瘤有一定的特征性MRI表现,特别是纤维型、血管外皮型、血管母细胞型脑膜瘤具有明显MRI特征。     

椎管内微小占位性病变的MRI诊断

目的:研究椎管内微小占位性病变的MRI特征及其对病变定性、定位诊断的意义。材料与方法:24例椎管内微小占位性病变患者(男12例,女12例,年龄23～67岁,平均29.1岁)均经PHILIPS 1.0NT型MR仪行常规T_1WI、T_2WI磁共振成像,其中6例又经Gd-DTPA增强扫描。全部病例的椎管内占位病变均经病理证实,并对其MRI表现进行了回顾性分析。结果:24例的病变经病理证实,18例为胚胎源性肿瘤(10例表皮样囊肿,4例皮样囊肿,4例畸胎瘤),4例为神经源性肿瘤(3例神经鞘瘤,1例神经纤维瘤),以及脊膜瘤与脂肪瘤各1例。各种占位性病变的MRI表现随其不同的组织学来源而有很大差别。表皮样囊肿多为均质长T_1长T_2信号。皮样囊肿以短T_1,长T_2信号为主。畸胎瘤呈混杂信号。神经鞘瘤为T_1WI低信号、T_2WI高信号,Gd-DTPA增强扫描后,囊壁均匀强化,偶见强化附壁结节。神经纤维瘤呈均质长T_1、长T_2信号,Gd-DTPA增强扫描后,病灶呈异常对比增强。脊膜瘤呈长T_1、稍长T_2信号,Gd-DTPA增强扫描后,病灶呈异常对比强化,并见局部硬脊膜增厚强化而形成的硬膜尾征。结论:各种病变的MRI表现随其组织学来源不同而有明显差异,它们在椎管内微小占位性病变的定性、定位诊断中起着重要作用,其诊断准确性优于X线椎管造影与CT。     

联合MRI和CT诊断微小脑膜瘤

目的 探讨微小脑膜瘤CT和MRI早期敏感征象,提高其检出率.方法 回顾性分析41例经临床随访及病理确诊为微小脑膜瘤的临床及影像学资料,观察并记录微小脑膜瘤发生部位、CT密度、MRI信号特点,对结果进行统计学分析.结果 21例患者行CT平扫检查,其中5例呈钙化密度,12例呈高/稍高密度,4例呈等密度.41例患者均行MRI检查,T1 WI:37例呈等信号,4例呈低信号;T2 WI:33例呈等信号,4例呈高信号,4例呈低信号;FLAIR:14例呈略高信号,27例呈等信号.13例患者行扩散加权成像(DWI)检查,其中5例呈高/稍高信号.MR增强扫描病变均呈明显强化.结论 MR多序列(FLAIR、DWI)、多方位(矢状面)结合增强扫描、薄层扫描并联合CT平扫可极大地减少微小脑膜瘤的漏诊率.     

平扫和动态增强MR诊断肝脏增生性结节

目的 总结增生性结节(DN)在MRI平扫及动态增强扫描中的特征. 资料与方法 回顾性分析行Gd-DTPA动态增强MR检查并经手术病理证实的DN共11例16个病灶,观察病灶的大小、信号强度、强化方式和时间,测量各序列病灶及周围肝组织的信号强度和背景噪声标准差,计算信噪比及其差值.绘制病灶和周围肝组织的时间-信号强度曲线. 结果 16个病灶中有4个表现为"结中结",中央结节为T1WI低、T2WI等或高信号,动态增强为速升速降或速升缓降型,周围为T1WI高、T2WI等或高信号,动态增强为缓慢上升型;余12个病灶在T1WI上高、等和低信号均有,在T2WI上为等信号和稍高信号,动态增强过程中动脉期强化较明显,门静脉期以等信号为主,延迟期为等及稍高信号, 未见呈低信号者.时间-信号强度曲线显示病灶为速升缓降型. 结论 "结中结"征象和动态增强早期强化、后期与周围肝组织类似信号的表现是DN的MRI特征.     

三叉神经节和Meckel''s腔原发性肿瘤的MRI表现

目的 研究三叉神经节和Meckel’s腔原发肿瘤的MRI表现。方法 对14例经病理证实的三叉神经节和Meckel’s腔原发肿瘤患包括4例三叉神经鞘瘤，5例脑膜瘤，1例脂肪瘤，以及4例表皮样囊肿的MRI表现进行了分析。结果 三叉神经鞘瘤在T1WI上呈均匀低信号，在T2WI上呈高信号。5例脑膜瘤中的3例在T1WI和T2WI上与周围脑组织信号一致，1例在T1WI上呈低信号，在T2WI上呈高信号，另1例在CT图像上有丰富的钙质沉着而在T1WI和T2WI上均呈低信号。脂肪瘤信号均匀且与眶内和皮下脂肪信号一致。4例表皮样囊肿的2例在T1WI和T2WI上呈非常高的信号，另外2例呈匍匐性生长并且占位效应较轻。肿瘤侵犯三叉神经能很好的显示其范围。结论 发生自三叉神经节和Meckel’s腔的不同原发肿瘤具有各自的信号特征，可通过MR成像予以鉴别。