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。     

Prediction of tumor-brain adhesion in intracranial meningiomas by MR imaging and DSA.

OBJECTIVES: The purpose of this study was to evaluate the usefulness of MRI (magnetic resonance imaging) and DSA (digital subtraction angiography) by using preoperative MRI and DSA findings in the examination of meningiomas before excision. In particular, we focused on their usefulness in predicting tumor-brain adhesion during surgery. MATERIALS AND METHODS: The subjects were 36 patients with intracranial meningioma who underwent tumor excision at which time neurosurgeons examined the tumor-brain adhesion. Two neurosurgeons evaluated the degree of tumor-brain adhesion from operation records and videotapes recorded during surgery. Two neuroradiologists retrospectively evaluated the preoperative MRI findings including tumor diameter, signal intensity of the tumor parenchyma obtained with T(2)-weighted imaging (T(2)WI), characteristics of the tumor-brain interface, and degree of peritumoral brain edema. The vascular supply was also evaluated from the preoperative DSA findings. The relationship between these MRI and DSA findings and the degree of tumor-brain adhesion during surgery as classified by the neurosurgeons was statistically analyzed. RESULTS: The degree of peritumoral brain edema and the shapes and characteristics of the tumor-brain interface, including the findings of FLAIR (fluid-attenuated inversion recovery) imaging and vascular supply observed by DSA, were significantly correlated with tumor-brain adhesion. In particular, the shapes and characteristics of the tumor-brain interface as observed by T(1)-weighted imaging (T(1)WI), T(2)WI, and FLAIR, respectively, as well as the vascular supply observed by DSA, were closely correlated with the degree of tumor-brain adhesion encountered during surgery. According to these results, we developed a method of predicting tumor-brain adhesion that considers the shape of the tumor-brain interface revealed by MRI and the vascular supply revealed by DSA. CONCLUSIONS: We retrospectively examined the findings of MRI and DSA performed before excision of meningioma and clarified the relationship between the findings and tumor-brain adhesion. We speculated that tumor-brain adhesion can be accurately and simply predicted before surgery with a new method that considers the shape of the tumor-brain interface observed by MRI and vascular supply observed by DSA.     

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。     

Microcystic meningioma: importance of obvious hypointensity on T1-weighted magnetic resonance images

PURPOSE: To investigate the sensitivity and specificity of various magnetic resonance imaging findings for microcystic meningioma. METHODS: Magnetic resonance images of 26 patients with microcystic meningioma (8 from our series and 18 from the literature) and 32 control subjects with other types of meningiomas were evaluated for obvious hypointensity relative to the cerebral cortex on T1-weighted images (T1WIs), obvious hyperintensity relative to the cerebral cortex on T2-weighted images (T2WIs), a radial or sunburst vascular pattern, marginal and reticular enhancement, severe peritumoral brain edema, and the dural tail sign. Differences in the frequencies of these findings between the microcystic and control groups were examined by means of the chi2 test. The sensitivity, specificity, positive predictive value, and negative predictive value of these findings in the diagnosis of microcystic meningioma were calculated. Multivariate analysis of the findings was also performed. RESULTS: The frequencies of obvious hypointensity on T1WI, obvious hyperintensity on T2WI, marginal and reticular enhancement, and severe peritumoral brain edema significantly differed between the microcystic and control groups (all P < 0.005). Sensitivities and specificities of hypointensity on T1WI and hyperintensity on T2WI in the diagnosis of microcystic meningioma were greater than 87%. After multivariate analysis, obvious hypointensity on T1WI was the only significant predictor of microcystic meningioma, with an odds ratio of 75.0 (95% confidence interval, 3.7-1536.0). CONCLUSION: Obvious hypointensity relative to the cerebral cortex on T1WI was the most valuable magnetic resonance finding in the diagnosis of microcystic meningioma.     

椎管内肿瘤的MRI表现(附75例分析)

目的：评价ＭＲＩ 诊断椎管内肿瘤的价值。材料与方法：回顾性分析７５ 例经手术及病理证实的椎管内肿瘤的ＭＲＩ 表现。结果：髓内肿瘤２０ 例。室管膜瘤两端有囊性改变,瘤体边界清楚,囊壁转移及瘤体增强明显。胶质瘤边界不清,脊髓水肿明显,有点状及絮状增强。髓外肿瘤５５ 例。神经源性肿瘤及脊膜瘤均有清楚界限,前者可呈哑铃状生长,中央部分不增强,可呈多房性。后者增强较均匀,靠近脊膜侧呈宽基底。脂肪瘤呈特殊的Ｔ１ ＷＩ 高信号,Ｔ２ＷＩ 为灰色。血管脂肪瘤Ｔ１ＷＩ 呈高信号,增强后采用抑脂（ＦＡＴＳＡＴ） 序列扫描呈高信号。脊索瘤为骶尾段自椎骨向椎管内生长,破坏的骶骨呈长Ｔ１ 和长Ｔ２ 信号。髓母细胞瘤骶管内种植转移灶上缘呈结节状,信号不均匀。结论：ＭＲＩ 结合ＧｄＤＴＰＡ增强扫描,对椎管内肿瘤的定位及定性诊断具有重要价值。     

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。     

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。     

脑室内脑膜瘤的影像学表现及其病理基础

目的探讨脑室内脑膜瘤影像学特征及其病理基础。方法通过回顾性分析经手术病理证实的11例脑室内脑膜瘤的CT、MRI表现,总结其影像学特征及其病理基础。结果本组11例患者,其中8例位于侧脑室,3例位于三脑室。除1例与瘤周脑组织分界不清、浸润性生长、水肿较明显外,余肿瘤呈不规则形分叶状(7例)或类圆形(3例)、边界较清,相应脑室不同程度扩大,邻近脑实质轻度水肿。MRI表现为T1WI等(2例)或稍低信号(9例),T2WI表现为等、稍高或混杂高信号,增强扫描呈显著不均匀强化。CT平扫表现为均匀或不均匀略高密度影。结论脑室内脑膜瘤的影像学表现具有特征性,MRI结合CT能较好地显示肿瘤的病理解剖特征。     

Serial MR Imaging of Intramuscular Hematoma: Experimental Study in a Rat Model with the Pathologic Correlation

Objective

We wanted to demonstrate the temporal changes of the magnetic resonance imaging (MRI) findings in experimentally-induced intramuscular hematomas in rats and to correlate these data with the concurrent pathologic observations.

Materials and Methods

Intramuscular hematoma was induced in 30 rats. The MR images were obtained at 1, 4, 7 and 10 days and at 2, 3, 4, 6 and 8 weeks after muscle injury. The characteristic serial MRI findings were evaluated and the relative signal intensities were calculated. Pathologic specimens were obtained at each time point.

Results

On the T1-weighted imaging (T1WI), the intramuscular hematomas exhibited isointensity compared to that of muscle or the development of a high signal intensity (SI) rim on day one after injury. The high SI persisted until eight weeks after injury. On the T2-weighted imaging (T2WI), the hematomas showed high SI or centrally low SI on day one after injury, and mainly high SI after four days. A dark signal rim was apparent after seven days, which was indicative of hemosiderin on the pathology. The gradient echo (GRE) imaging yielded dark signal intensities at all stages.

Conclusion

Unlike brain hematomas, experimentally-induced intramuscular hematomas show increased SI on both the T1WI and T2WI from the acute stage onward, and this is pathologically correlated with a rich blood supply and rapid healing response to injury in the muscle. On the T2WI and GRE imaging, high SI with a peripheral dark signal rim is apparent from seven days to the chronic stage.     

富于淋巴浆细胞型脑膜瘤的MRI与病理分析

目的 探讨脑膜瘤亚型富于淋巴浆细胞型的MRI表现特征.方法 回顾性分析7例经手术病理证实的富于淋巴浆细胞型脑膜瘤的影像资料及病理资料,结合相关文献进行对比分析.结果 7例富于淋巴浆细胞型脑膜瘤均为单发病灶,6例病灶沿脑膜匍匐性生长,5例未形成具体瘤结节,2例为不规则分叶状;7例病灶均界限不清,瘤周水肿明显,邻近脑组织不同程度受累.MR平扫T1WI 7例均呈等、略低信号,T2WI 5例呈等、略高信号,2例呈等、略低信号;增强扫描见7例病灶均有显著强化效应,6例脑膜广泛不均匀增厚.病理示细胞丰富,成分多样,见大量淋巴细胞、浆细胞浸润,可见多少不等的梭形瘤细胞及典型脑膜上皮细胞区域.结论 富于淋巴浆细胞型脑膜瘤影像表现不同于常见脑膜瘤,具有一定的影像表现特征,有助于该肿瘤的诊断和鉴别.     

恶性脑膜瘤的CT、MRI影像分析

目的探讨恶性脑膜瘤的CT、MRI的影像学特征,以提高诊断正确率,为临床手术提供可靠依据。方法回顾性分析近几年来我院经手术病理证实的恶性脑膜瘤(35例)的CT、MRI资料。结果恶性脑膜瘤:(1)T2WI信号及密度不均29例(82.1%);(2)T1WI信号不均27例(77.1%);(3)边缘不规则21例(60%);(4)粗短的硬脑膜尾征19例(54.2%);(5)颅骨受侵8例(22.8%);(6)瘤内钙化14例(40%);(7)多发2例(占5.7%)。结论恶性脑膜瘤的影像学表现具有一定的特征性,定性诊断需要综合分析,注意与良性脑膜瘤的鉴别。     

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。     

脑膜瘤的MRI征象及相关病理(附51例病例分析)

目的:分析脑膜瘤MRI表现及其相关病理.方法:回顾性分析51例经手术证实的脑膜瘤MRI图像,从其信号特点、肿瘤-脑组织界面、瘤周水肿、脑膜尾征病灶增强后MRI信号均匀度等方面进行归纳,并观察相关病理学资料.结果:脑膜瘤大多T1WI为等低信号,T2WI以稍高信号和混杂信号多见,脑膜尾征具有诊断价值.结论:脑膜瘤MRI征象有较高的敏感性和特征性,大多数能在术前诊断,为手术方式提供帮助.     

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。     

实验性癫癎大鼠脑MRI与病理学对照研究

目的：观察１．５Ｔ ＭＲＩ检出大鼠痫性脑损伤的能力。材料和方法：Ｗｉｓｔａｒ大鼠３０只,毛果云香碱３５０ｍｇ／ｋｇ腹腔注射,诱发反复强真－痉挛全面大发作持续状态,ＨＦ染色,光镜下观察癫痫持续不同时间脑组织损害程度,并与１．５Ｔ ＭＲ成像对比（ＭＲＩ参数：ＳＥ序列Ｔ１加权像：重复时间＝５００ｍｓ,回波时间＝１５ｍｓ;ＦＳＥ序列Ｔ２加权像：重复时间＝４００ｍｓ;用表面线圈,层厚２．２ｍｍ,无间隔）。结果：癫痫持续时间与脑损伤呈相关性改变。癫痫持续３ｄ后,可见颞叶、海马区严重神经元脱失、胶质增生和脑水肿,ＭＲ扫描除在１只发作持续１８ｈ的大鼠左颞区检出长Ｔ１、长Ｔ２异常信号外（光镜提示为在灶）,未发现其余动物脑的结构异常和信号变化。结论：随着动物大发作持续时间延长,痫性脑损害加重,大鼠癫痫持续３ｈ以上,有明显的海马神经     

恶性脑膜瘤MR诊断

目的　探讨恶性脑膜瘤的MRI表现 ,提高术前诊断率。方法　选取经手术病理证实且MR检查资料完整的病例 18例。结果　T1加权像均呈不规则混杂信号 ,以等低信号为多见 ( 16/18) ,T2 加权像以高等混杂信号为多见 ( 14 /18)。增强扫描 ,肿瘤均显著强化 ,且以不均匀强化常见 ( 15 /18) ,肿瘤形态多不规则 ,呈分叶状 ,部分或全部境界模糊。结论　恶性脑膜瘤除具有良性脑膜瘤MR表现外 ,还具有一定特异性。     

囊性脑膜瘤的MRI表现(附37例报告)

目的探讨囊性脑膜瘤的MR I表现,以提高诊断准确率。方法囊性脑膜瘤患者37例,采用1.5T磁共振扫描仪分别行轴位、矢状位和冠状位颅脑扫描,其中20例行Gd-DTPA增强扫描。观察囊性脑膜瘤的MR I表现,并分析不同类型囊性脑膜瘤的特点。结果囊性脑膜瘤除具有脑膜瘤常见的MR I表现外,由于囊腔的存在,囊性脑膜瘤的信号不均匀,周围常有明显脑水肿,肿瘤边缘模糊不清较脑膜瘤多见。3例Nauta 1型囊性脑膜瘤中,囊变、坏死位于肿瘤中央,16例Nauta 2型囊性脑膜瘤中,囊变、坏死位于肿瘤周边,Nauta 1型和Nauta 2型囊性脑膜瘤的囊腔四周均有肿瘤组织。3例Nauta 3型和5例Nauta 4型囊性脑膜瘤中,坏死、囊变区位于肿瘤实质部分的周边,Nauta 3型者肿瘤和囊腔之间有脑组织相隔,而Nauta 4型中肿瘤则与囊腔直接相邻。10例为上述4型中某2种或2种以上的混合型。结论MR I对囊性脑膜瘤的诊断和分型有较大价值。     

Magnetic resonance imaging spectrum of spinal meningioma

PurposeTo evaluate magnetic resonance (MR) imaging findings of spinal meningioma and to determine the radiological subtypes based on the MR imaging findings and their respective clinical features.Material and methodsData for 105 patients with surgically treated and histopathologically diagnosed spinal meningiomas at our hospital between May 1, 2003 and May 1, 2017 were evaluated in this study. Two radiologists reviewed the characteristics of spinal meningiomas on MR images and categorized the spinal meningiomas into subtypes based on MR imaging findings.ResultsMost spinal meningiomas showed higher signal intensity than that of the spinal cord but lower than that of the subcutaneous fat on T2-weighted images (WI). 56 cases (54%) showed adjacent spinal cord signal changes. Meningiomas could be categorized according to MR imaging findings into type A: dural-based tumors with a homogeneous signal intensity and intense contrast enhancement (81 cases, 77%); type B: round or oval-shaped tumors with an internal hypointense portion on T2-weighted images (18 cases, 17%); type C: en plaque tumors (three cases, 3%); and type D: tumors with unusual findings and a heterogeneous appearance (three cases, 3%). All type C patients showed spinal cord signal changes.ConclusionsSpinal meningioma showed slightly high signal intensity rather than high signal intensity on T2-weighted images. Spinal cord signal changes were present in more than half of the cases. Clinical differences were observed among the different MR imaging types.     

急性胰腺炎的MRI诊断

目的　评价MRI在急性胰腺炎诊断中的作用。方法　 77例急性胰腺炎的病人全部采用屏气磁共振序列进行扫描。横断位扫描: 2DFlashT1WI/T1WI+FS,TSET2WI+FSHASTE+FS,部分病人加扫Trufisp序列。冠状位扫描: 2DFlashT1WI+FS;其中 34例病人进行了MRCP检查。所有 77例病人均进行了MRI动态增强扫描。结果　59例诊断为急性水肿性胰腺炎,表现为胰腺肿胀,T1WI稍低信号,T2WI稍高信号。18例诊断为出血坏死性胰腺炎,除前述表现外,还可见T1WI斑片状高信号,胰周渗液明显。结论　MRI对急性胰腺炎的诊断具有重要作用。