脑室内脑膜瘤的MRI诊断

目的:探讨脑室内脑膜瘤MRI的特点,提高其诊断及鉴别诊断水平.材料和方法:回顾性分析15例经手术病理证实的脑室内脑膜瘤的MRI特点.结果:15例中11例位于侧脑室,4例位于四脑室.术前准确定位15例,准确定性10例.MRI示病灶呈分叶状11例,类圆形4例,病灶边界清晰;平扫时肿瘤信号均匀15例.T1WI呈等信号或稍低信号,T2WI呈稍高信号或等信号.增强扫描中到重度均匀增强9例,不均匀增强6例;瘤内可见较粗大血管影4例.囊变、坏死2例.无宽基底及脑膜尾征.脑积水4例,瘤周脑实质轻度水肿6例.结论:大多数脑室内脑膜瘤有MRI特征,MRI为影像诊断首选.     

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.     

鞍旁海绵状血管瘤与脑膜瘤的MR鉴别诊断

目的探讨鞍旁海绵状血管瘤与脑膜瘤的MR鉴别诊断要点。方法收集我院经手术病理证实的6例鞍旁海绵状血管瘤和15例鞍旁脑膜瘤的影像资料,比较两者MRI平扫及增强扫描表现的不同之处。结果鞍旁海绵状血管瘤以稍长T1、长T2为主要表现,DWI呈等信号,ADC值约为1.63×10-3 mm2/s,增强扫描3例早期明显均匀强化,3例延迟后均匀强化,邻近颞叶无水肿,颈内动脉海绵窦段包绕或被推压。鞍旁脑膜瘤表现为等T1、等T2信号常见,DWI呈等或略高信号,ADC值约为0.93×10-3 mm2/s,病变明显强化,12例可见"脑膜尾征"。结论鞍旁海绵状血管瘤T2WI呈明显高信号、ADC值高,脑膜瘤可见"脑膜尾征"。     

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。     

微囊型脑膜瘤的MRI表现

目的 探讨微囊型脑膜瘤(MCM)的MRI表现及其诊断价值.资料与方法 回顾性分析8例经手术病理证实的MCM患者的影像学及病理资料,并与病理对照.结果 病变位于额部6例(左侧4例,右侧2例),右侧顶部大脑镰旁1例,右侧桥脑小脑角区1例;8例中5例平扫T1 WI呈低信号,T2WI呈明显高信号,增强后病变呈明显不均匀强化;3例平扫时T1WI呈不均匀等低信号,T2WI呈不均匀等高混杂信号,增强后病变呈明显不均匀强化;8例病变中4例可见"脑膜尾征";6例可见中重度瘤周水肿;肿瘤组织中见瘤细胞排列疏松,呈微囊状.结论 MCM是颅内少见肿瘤,MRI表现有一定特点,T2WI呈明亮高信号,增强后呈明显强化,MRI对其诊断和鉴别诊断具有重要临床价值.     

多发脑膜瘤的CT和MRI诊断及相关特征

目的:探讨多发脑膜瘤的CT和MRI表现及其相关临床特征.方法:回顾性分析19例经手术病理证实的颅内多发脑膜瘤的影像和临床资料.结果:19例患者共栓出51个肿瘤,以直径小于1.5 cm者居多(占40/51),大脑凸面病灶周围水肿较明显.CT平扫肿瘤呈等密度或稍高密度;T1 WI上呈等信号或稍低信号,T2 WI呈等信号或稍高信号;增强扫描显示肿瘤实体部分均匀强化,边缘清楚,"硬脑膜尾征"在直径小于1.0 cm的肿瘤中出现的概率较小.结论:多发性脑膜瘤有一定的影像学特征,MRI可发现CT扫描漏检的小病灶,明确多发性脑膜瘤的部位、大小和数目,有助于临床制订合理的治疗方案和评估预后.     

恶性脑膜瘤的CT、MRI分析

目的 探讨恶性脑膜瘤的CT、MRI的影像学特征.方法 回顾性分析近几年来本院经手术病理证实的恶性脑膜瘤(35例)的CT、MRI资料.结果 恶性脑膜瘤影像学表现包括:(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)其中2例为多发(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.     

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。     

《请您诊断》病例49答案:前颅底孤立性浆细胞肉芽肿

病例资料患者,女,39岁。因嗅觉消失1月余就诊,无其他不适。查体无明显阳性体征。CT检查示前颅窝团片状软组织密度影,前颅底、前床突、后床突和筛窦壁骨质吸收、破坏,伴部分骨质硬化,蝶鞍扩大、鞍底凹陷（图1~3）。头颅MRI示病灶于T1WI上呈等信号影、T2WI上呈等偏高信号影,增强后病灶呈明显均匀强化,邻近脑膜可见增厚、强化呈＂脑膜尾征＂（图4~7）。CT及MRI诊断为侵袭性脑膜瘤。术中所见与CT、     

颅中窝海绵状血管瘤的影像及其鉴别诊断

目的:探讨颅底海绵状血管瘤的影像特征及其鉴别诊断,提高影像定性诊断率。方法:总结11例颅底鞍旁海绵状血管瘤(CA)病例,对其影像进行回顾性分析。结果:CT表现呈圆形略高密度均一肿块,增强后强化明显;MRI平扫T1WI、T2WI呈底向外的葫芦状、长T1长T2信号改变,增强后同样明显强化;DSA呈棉絮状染色,MRA不显影。术前影像定性诊断准确率45.5%(5/11)。结论:CT表现与其它实体肿瘤相比无特异性,定性诊断困难;MRI表现呈底向外的葫芦状、长T1长T2信号改变较具特征性;“脑膜尾”征改变并非为脑膜瘤所特有,脑外CA同样常见。     

椎管内脊膜瘤及神经源性肿瘤MRI增强影像的特征性分析

目的:分析椎管内脊膜瘤及神经源性肿瘤MR增强影像的特征。方法:搜集经手术病理证实的椎管内脊膜瘤11 例,神经源性肿瘤12例,全部病例均行MR平扫及增强扫描。结果:椎管内脊膜瘤MR增强影像特征为“肿瘤周边重度环状增强”、脊膜“尾巴征”;神经鞘瘤MR增强影像特征为多灶样不增强;神经纤维瘤MR增强影像特征为病灶内星芒状不增强。结论:椎管内脊膜瘤及神经源性肿瘤都有各自的MR增强影像特征,其对定性诊断有重要价值     

子宫良性肿瘤的MRI检查和诊断

目的：分析各种子宫良性肿瘤ＭＲＩ 图像,探讨ＭＲＩ 在子宫良性肿瘤中的诊断价值。材料和方法：共收集本院１９９４ － １９９９ 年临床疑子宫良性肿瘤病人３９ 例。ＭＲＩ 检查在ＧＥ Ｖｅｃｔｒａ０ ．５Ｔ 和ＧＥｓｉｇｎａ Ｈｏｒｉｚｏｎ１ ．５Ｔ 超导成像仪上进行,采集矢状面ＦＳＥ Ｔ２ ＷＩ 像,横断面ＳＥ Ｔ１ ＷＩ 像和ＦＳＥ Ｔ２ ＷＩ 像,并对各种病变所致子宫和宫颈的位置、大小、外形与其各层结构变化进行仔细观察和分析,与手术病理对照,以确定ＭＲＩ 的诊断价值。结果：３９例ＦＳＥ Ｔ２ ＷＩ 图像均清晰显示子宫及宫颈诸层结构;矢状面更可清楚显示子宫位置和大小。３９ 例病变均经病理证实,２３ 例为子宫肌瘤,子宫形态均增大,连结层和内膜层可受压,其中１７ 例Ｔ１ ＷＩ 和Ｔ２ ＷＩ 上表现为低信号影,６ 例为低到高不均匀信号影。１２ 例为子宫腺肌瘤,Ｔ２ ＷＩ 上连结层结构不清及较低信号,且增厚。１ 例为纳氏囊肿,Ｔ１ ＷＩ 上为子宫颈后壁内低信号囊状影,边缘光滑,Ｔ２ ＷＩ 上为均匀高信号影。本组有１ 例多发性肌瘤出血ＭＲＩ 上被误诊为子宫腺肌瘤;有２ 例子宫浆膜下肌瘤似游离于盆腔内,而漏诊。结论：ＭＲＩ 横断面及矢状面ＦＳＥ Ｔ２ ＷＩ 能清晰显示     

MR studies of extension and spread pattern of nasopharyngeal carcinoma

Seven patients with T2-T4 nasopharyngeal carcinoma were examined by MRI on a 0.5T superconducting system. The obtained MRI images were reviewed focusing on the signal intensity (SI) of tumors, and the extension of tumors into the related spaces from the pharyngeal mucosal space (PMS). Consequently, the SI of tumors demonstrated low on T1 weighted images and high on T2 weighted images. The parapharyngeal space was the first space where the tumors extended from the pharyngeal mucosa. The parapharyngeal space was an intermediate point of extension to the masticator space (MS), the carotid space (CS), the retropharyngeal space (RPS), and the prevertebral space (PVS). The PVS involvement by tumors was not a direct extension from the PMS, because the posterior portion of pharyngobasilar fascia worked as a barrier on MR. Therefore, the longus capitus muscle in the prevertebral space was considered to be involved via the parapharyngeal space (PPS). The masticator space involvement was indicated by slightly high SI of pterygoid muscle on T2 weighted images, and also the effacement of the PPS fat and parapharyngeal venous plexus were considered as a sign of involvement into the masticator space. The retropharyngeal lateral lymph node (Rouviere) metastases were recognized by MR. These metastasized lymph nodes were low on T1 weighted images and high on T2 weighted images.     

颅内浆细胞肉芽肿的CT、MRI表现

目的探讨颅内浆细胞肉芽肿的CT、MRI特征。方法对经手术、病理证实的3例颅内浆细胞肉芽肿的临床资料进行了回顾性分析,并复习了近几年国外文献。结果2例CT显示单发圆形或类圆形分叶状低、等密度肿块,伴有灶周水肿、占位效应和硬膜尾征,呈均一强化。MRI显示T     

纤维型脑(脊)膜瘤MRI诊断

目的 探讨纤维型脑（脊）膜瘤的MRI影像特征。方法 10例手术病理证实的纤维型脑 （脊）膜瘤，位于颅内7例（大脑镰旁、后颅窝各2例，右颞部、侧脑室及前颅窝嗅沟各1例），颅颈交界区1例，胸椎管2例，于静脉注射造影剂前后，均经FSE序列T1加权和T2加权磁共振成像，并分析其MRI影像表现。结果 5例颅内脑膜瘤与1例颅颈交界区脑（脊）膜瘤T1WI呈等信号，T2WI中央极低信号，周围等信号，增强扫描中央轻度强化，周围明显强化;2例颅内脑膜瘤（其中1例位于右侧侧脑室）与2例胸椎管内脊膜瘤T1WI与T2WI均呈等信号，增强扫描明显均匀强化。除1例侧脑室脑膜瘤外所有肿瘤以宽基底贴敷于硬脑（脊）膜，其中，3例增强扫描可见“脑（脊）膜尾征”。结论 纤维型脑（脊）膜瘤有典型的MRI特征，MRI对其诊断有较高价值。     

Lymphoma presenting as a musculoskeletal soft tissue mass: MRI findings in 24 cases

The purpose was to describe the MRI morphological features and signal intensity (SI) characteristics of 24 histologically proven cases of musculoskeletal soft tissue lymphoma presenting clinically as a suspected primary soft tissue sarcoma. This was a retrospective review of clinical notes and MRI studies of 24 patients with a histologically confirmed diagnosis of lymphoma. All patients presented to a specialist orthopaedic oncology unit with a suspected primary soft tissue sarcoma. Features assessed included lesion size and morphology, location, extension across anatomical compartments and signal intensity characteristics. The lesions were predominantly poorly defined with peritumoral oedema in ten cases. All tumours were of intermediate T1W SI, while 85% of lesions also showed intermediate T2W SI. Almost all cases that were located just deep to the fascia showed subcutaneous extension, while 50% had involvement of more than one muscle compartment. In 29% of cases, there was extension of tumour along the neurovascular bundle. Histo-pathologically, 23 lesions were non-Hodgkin’s B-cell lymphoma. The MRI features of primary musculoskeletal soft tissue lymphoma include a mass with intermediate SI on T1W and T2W images, involvement of more than one anatomical compartment, subcutaneous extension and extension along the neurovascular bundle.     

MRI鉴别囊变脑膜瘤与脑表面囊变胶质瘤的价值

目的：探讨囊变脑膜瘤与靠近脑表面囊变胶质瘤的MRI表现,以提高鉴别诊断水平。方法：回顾性分析经术后病理证实的囊变脑膜瘤38例与靠近脑表面囊变胶质瘤21例,分析增强后病灶边缘的＂脑膜尾征＂、＂白质塌陷征＂、＂毛刺征＂及＂指状水肿征＂、＂宽基底征＂及＂强化均匀＂的例数,并作统计学分析。结果：脑膜瘤组的脑膜尾征、白质塌陷征、毛刺征、宽基底征、指状水肿征及肿瘤实质强化均匀的检出率分别为73.7%（28/38）、76.3%（29/38）、10.5%（4/38）、81.6%（31/38）2、3.7%（9/38）及57.9%（22/38）;而胶质瘤组则分别为23.8%（5/21）、19.0%（4/21）、38.1%（8/21）、57.1%（12/21）5、2.4%（11/21）及33.4%（7/21）。白质塌陷征、脑膜尾征、宽基底征、毛刺征及指状水肿征在脑膜瘤组与胶质瘤组差异有统计学意义（P〈0.05）;肿瘤实质强化均匀在二组间差异无统计学意义（P〉0.05）。结论：脑膜尾征、白质塌陷征、宽基底、毛刺征、指状水肿征对鉴别脑膜瘤与胶质瘤价值较大,而强化较均匀对二者的鉴别意义不大。     

Nodular fasciitis: correlation of MRI findings and histopathology

OBJECTIVE: To compare the histopathology of nodular fasciitis (NF) with the magnetic resonance imaging (MRI) findings in order to evaluate the basis of the MR signal characteristics. DESIGN AND PATIENTS: Ten patients with NF, nine females and 1 male, with an age ranging from 13 to 58 years (mean 26.8 years) were studied. MRI findings, available in all 10 patients, were compared with the histopathology in nine patients, and an area-to-area comparative study of the whole specimen section histopathology and MRI was performed in two patients. RESULTS: On the basis of an excisional biopsy or resection specimen, the nine lesions were classified into myxoid ( n=4), cellular ( n=3) and fibrous ( n=2) subtypes. Four myxoid lesions with a subcutaneous location showed a homogeneous SI comparable with muscle on T1-weighted images, high SI on T2-weighted images, and had homogeneous enhancement. One cellular lesion presented with homogeneous, slightly higher SI than muscle on T1-weighted images and inhomogeneous, high SI on T2-weighted images. Alcian blue stain of the whole specimen section revealed the lesion had two parts corresponding to different enhancement patterns on MRI. The blue-stained myxoid part showed markedly diffuse enhancement, while the non-stained cystic space had only peripheral enhancement. Two other cellular lesions had the same appearance on both T1- and T2-weighted images and showed inhomogeneous, diffuse enhancement. One fibrous subtype lesion presented with inhomogeneous, overall slightly higher SI than muscle on T1-weighted images, lower SI at the periphery and high SI in the center on STIR images and only peripheral enhancement. Microscopy and CD-31 staining of the lesion showed more extracellular matrix, with poor vascularity in the center and more collagenous matrix with higher vascularity at the periphery. CONCLUSION: Although similar findings were found in some lesions, the large histologic variability of NF hampers the definition of a prototype of NF on MRI. However, the MRI appearance of the myxoid subtype is rather characteristic. Histologic findings reflect the different SI characteristics and enhancement pattern on MRI.     

肝细胞癌的低场MR征象分析(附33例报告)

目的分析肝细胞癌在低场MR的征象.方法收集33例手术病理证实的肝细胞癌的术前低场MR资料进行分析.结果1.肿瘤实质信号均匀区的信号配对主要分为三类1T1WI稍低、T2WI稍高信号18例;2T1WI等、T2WI稍高信号13例;3T1WI稍高、T2WI稍高信号2例.2.肿瘤实质内MR异常信号区1T1WI低、T2WI高信号(斑点状24例,片状9例,条状5例);2T1WI稍低、T2WI高信号(斑点状8例,片状2例,条状3例);3T1WI高、T2WI高信号(斑点状4例,片状2例);④T1WI低、T2WI低信号(斑点状5例,片状6例,条状2例).3.肿瘤边缘在T2WI上分三种1边缘清楚无分叶21例,其中11例可以见到"包膜征”;2边缘清楚伴分叶5例;3边缘不清7例.结论1低场MR中,肝细胞癌的肿瘤实质在T1WI可以是多种信号,缺乏特征性,但在T2WI均为稍高信号.2MR诊断肝细胞癌一定要有瘤内异常信号.3肝细胞癌的MR边缘部的形态应以T2WI为准,肿瘤边缘可以光滑清楚,也可以分叶状或边缘不清,"包膜征”有诊断意义.     

Dural tail sign in spinal meningiomas

OBJECTIVE: To study the association between the "dural tail sign" and spinal meningiomas on MR imaging. METHODS: Retrospective review of MR examinations of all pathologically proven spinal meningiomas from 1998 to 2005 was performed. Lesions were evaluated for size, signal intensity, enhancement pattern, and presence or absence of dural tail. The dural tail length and direction in reference to the meningioma were also evaluated. RESULTS: Seven spinal meningiomas were identified in seven patients. One lesion was purely extradural, while the remaining were intradural extramedullary. Dural tail was present in four cases (57%) and its length ranged between 5 and 21 mm. The tail was seen cranial and caudal to the meningioma in three cases and only cranially in one. Coronal images were available in three cases and in two of these; the dural tail was clearly depicted. CONCLUSIONS: "Dural tail sign" is as common in spinal meningiomas as in cranial meningiomas.