不同病理类型脑膜瘤的MRI特点及其临床意义

目的 分析不同病理类型脑膜瘤的MRI特点.方法 回顾性分析经手术和病理证实的428例脑膜瘤手术患者的病理类型;病理类型参照WHO 2007年版中枢神经系统肿瘤分型,利用PACS影像系统分析其MRI特点.结果 脑膜皮细胞型多为稍高或等T1、高T2信号,信号均匀;混合型可出现多种信号组合,内部不均匀;纤维型T1、T2多为等或稍低信号,信号均匀;砂粒体型多为低T1、T2信号,有时见到团状或斑块样信号;其他良性脑膜瘤少见,多为低或等T1信号,稍高T2信号;非良性脑膜瘤信号特征类似,多为低或等T1信号,稍高T2信号,内部囊变坏死多见,增强扫描强化不均匀.结论 不同病理类型脑膜瘤在MRI上信号表现有所不同.分析MRI信号特点,对术前判断肿瘤病理类型及术中肿瘤切除方式的选择有意义.

Abstract：

Objective To explore the characters of different types of meningiomas on MRI and the significance for surgical treatment.Methods The clinical data of 428 patients with meningiomas underwent surgery in Southern hospital from January 2000 to January 2010 were analyzed retrospectively.The pathological types of meningiomas were identified according to WHO 2007 edition.The characters of meningiomas on MRI were analyzed by PACS software.Results The MRI images of meningothelial type were slightly high or equal signal on T1 image and high signal on T2 image; the images of transitional( mixed)type on MRI were different and the signals were hybrid.The signals of fibrous type were slightly low or equal on both T1 and T2 and homogeneous.The signals of psammomatous type were low on both T1 and T2, and sometimes cystic degeneration and necrosis were found within tumors.The rest of benign meningiomas were rare and usually showed low or equal signals on T1 image and slightly high signals on T2 image.The signals of non - benign meningiomas were mostly low or equal on T1 image and slightly high on T2 image, and cystic degeneration,necrosis and heterogeneous enhancement were common to be seen.Conclusions Specific characteristics on MRI could be seen in different types of meningiomas.The knowledge of their correlations is helpful for preoperative diagnosis and surgical treatment in patients with meningiomas.     

Midkine expression in 52 human meningiomas

BACKGROUND： Several studies have shown that midkine directly participates in tumor cell growth and invasion, as well as the regulation of angiogenesis. OBJECTIVE： To investigate midkine expression in meningioma tissue in relation to angiogenesis, invasion, peritumoral edema, and clinicopathology. DESIGN, TIME AND SETTING： The present clinical, case-controlled, neuropathological study was performed at the Laboratory of Molecular Organism, People＇s Hospital of Deyang City between May 2007 and April 2008. MATERIALS： Fifty-two meningioma tissues were classified by WHO tumor classification of the central nervous system, comprising 40 grade Ⅰ meningioma, five grade Ⅱ meningioma, and seven grade Ⅲ meningioma. Ten normal, human cerebral maters were selected from cerebral trauma patients. METHODS： Midkine protein expression and mean microvessel density were detected using immunohistochemical techniques. Simultaneously, all data were statistically analyzed. MAIN OUTCOME MEASURES： Midkine expression and microvessel density in meningiomas and normal cerebral maters. RESULTS： The positive midkine expression rate was 64% in the meningioma tissues. However, midkine expression was not detected in normal cerebral mater tissue. The mean microvessel density was 82.0 ± 22.7 in the meningiomas, and 25.8± 6.2 in the normal cerebral mater tissues. There was significant difference in midkine expression and mean microvessel density between meningioma tissues and human cerebral maters （P 〈 0.05）. Midkine expression positively correlated with microvessel density （r = 0.756, P 〈 0.05）. Midkine expression did not correlate to patient age, gender, or tumor size, location, and shape （P 〉 0.05）. However, it closely correlated with patient clinical condition, pathological grade, invasion, and peritumoral edema （r = 0.3785,0.741 2,0.6518, 0.614 2, P 〈 0.05）. CONCLUSION： Midkine protein was overexpressed in meningiomas and correlated to tumor angiogenesis, invasion, pefitumoral edema, and clinicopa     

Clinical and pathological features in 49 elderly patients with meningiomas

BACKGROUND: As aging in elderly people, their brain tissue has degeneration and brain atrophy of different severity, and the volume of cranial cavity is relatively enlarged, it has greater compensatory ability to the space occupying lesion, and it is difficult to detect the meningioma because it grows to expand slowly, the tumor locates in non-functional region, and there are atypical symptoms and deficiency of localization signs. OBJECTIVE: To investigate the clinicopathologic features of senile meningiomas. DESIGN: A retrospective analysis. SETTING: Affiliated Hospital of Hebei University. PARTICIPANTS: Forty-nine elderly patients with meningioma were selected from the Department of Neurosurgery, Affiliated Hospital of Hebei University from May 1999 to March 2005, including 15 males and 34 females, 60–74 years of age, and they were all diagnosed by CT and MRI. METHODS: The sites of tumors were identified by CT and MRI examinations in all the patients. The tumors were partially or totally resected according to their own conditions. The types of the resected tumor were pathologically observed. The conditions of postoperative recovery were observed after 1, 3 and 6 months, and without new neurological dysfunction or complication was considered as good outcome. MAIN OUTCOME MEASURES: ① Sites and pathological types of the tumor; ② Postoperative outcomes and complications. RESULTS: All the 49 patients were involved in the analysis of results. ① The tumors had wide distributions with a main location in brain convexity. Among the 49 cases of meningioma, there were 25 cases of fibrocystic type, 12 cases of meningothelial type, 6 cases of psammomatous type, 4 cases of angiomatous type and 2 cases of microcystic type. ② Among the 49 patients, 35 had good outcome, 8 had self-care ability, 4 required care by others, 2 (4.1%) died postoperatively. No long-term complication related to the operation was observed during the follow-up postoperatively. CONCLUSION: Meningioma has a main location in brain convexity, and its pathological type is mainly fibrocystic one, and there is good operative outcome.     

Application of biological dural graft made by meninges from porkers

BACKGROUND: Presently, over 40 kinds of dural grafts have been successively used in clinic. Among them, lyophilized human dura mater with good histocompatibility and less complications is applied most widely. But there are a few reports on cases of infected spongiform encephalopathy following application of lyodura. More ideal repair materials deserve to be further investigated. OBJECTIVE: To investigate the efficiency and safety of biological dural graft made by meninges from porkers to repair meningeal injury. DESIGN: A self-control observation. SETTING: Wuhan General Hospital of Guangzhou Military Area Command of Chinese PLA. MATERIALS: Sixteen New Zealand Rabbits, of either gender, weighing from 2 to 3 kg, of clean grade Ⅱ, with the age of 0.5–1 year, were involved in this experiment. The involved rabbits were provided by the Animal Experimental Center of the First Military Medical University of Chinese PLA. Biological surgical patch (dural graft) was developed by Guangdong Guanhao Biotechnological Co.,Ltd. It was processed by using meninges from porkers by tissue engineering technology. METHODS: This experiment was carried out in the Experimental Center of the 157 Hospital of Chinese PLA between December 2003 and June 2004. ① The experimental rabbits were anesthetized. Dura mater was exposed from two sides of postmedial line of coronal suture. A rectangular dura mater about 8 mm×8 mm in size was cut off. Then a biological surgical patch (dural graft) was sheared into insert with 8 mm diameter and sutured. The left dura mater was untouched and used as control. Scalp was sutured, and postoperative wound healing and recovery were observed. ②The anesthetized rabbits were sacrificed at postoperative 3, 14, 30 and 90 days, 4 rabbits once. The whole head was cut off, and its scalp was removed. Afterwards, the head was fixed by formalin. Tissues in operative site were obtained, performed routine paraffin embedding, sliced and conducted HE staining, finally, the sections were observed. White blood cells in venous blood were counted before operation and execution, separately. The obtained data were statistically analyzed. MAIN OUTCOME MEASURES: ① Wound healing and recovery following implantation of dural graft. ②The amount of white blood cells in venous blood from rabbits at each time point before operation and before execution. ③ Histological examination results of operative site. RESULTS: Sixteen experimental rabbits were involved in the final analysis. ① The experimental rabbits of each group had no local infection, effusion and abnormal appearance. They had good wound healing and were normal to access to food. ② There were no significant differences in amount of white blood cells in venous blood from experimental rabbits between at each time point after modeling and before operation (P > 0.05). ③Pathological observation of operative site : At postoperative 3 days, local acute inflammation repair reaction appeared; At postoperative 2 weeks, chronic inflammatory reaction appeared, endodermis in artificial dural graft formed, and artificial dural graft and host dura mater healed; In postoperative 1 month, wound began to chronically recover; In postoperative 3 months, host blood capillary began to form in artificial dural graft based on chronic repair. In all the control sides, fibroplasia was found, and a few neutrophils were found at postoperative 2 weeks. CONCLUSION: Biological surgical patch has high stability and good histocompatibility. It can provide dural epithelial epithelium, effectively prevent against the conglutination of scalp tissue and brain tissue, and avoid the leakage of cerebrospinal fluid.     

Midkine expression in 52 human meningiomas:A correlation analysis

BACKGROUND: Several studies have shown that midkine directly participates in tumor cell growth and invasion, as well as the regulation of angiogenesis. OBJECTIVE: To investigate midkine expression in meningioma tissue in relation to angiogenesis, invasion, peritumoral edema, and clinicopathology. DESIGN, TIME AND SETTING: The present clinical, case-controlled, neuropathological study was performed at the Laboratory of Molecular Organism, People’s Hospital of Deyang City between May 2007 and April 2008. MATE...     

弥散张量成像对胶质瘤手术风险的评估

Objective To elucidate the clinical significance of diffusion tensor imaging (DTI) mainly used for protecting neurological functions in patients with gliomas. Methods Thirty - eight patients with gliomas were recruited to undergo DTI test and assess the status of neurological functions before and after surgery. According to the relationships between gliomas and adjacent white matter(WM) tracts, DTI can be classfied as the following types : type Ⅰ - displacement; type Ⅱ - Infiltration; type Ⅲ - Disruption. The neurological functions before surgery were compared in three groups,as well as the change of neurological functions after surgery was also compared in three groups. Results There were 14 cases in type Ⅰ , 16 cases in type Ⅱ, and 8 cases in type Ⅲ. There were significant difference between DTI types and preoperative neurological functions, as well as between DTI types and the change of postoperative neurological functions ( P < 0. 05 ). Conclusions DTI allows to visualizate the relationships of gliomas and adjacent WM tracts, which represent the different growth patterns of gliomas. It is useful for neurosurgeons to select suitable surgical approaches and determine appropriate extent of resection.     

弥散张量成像对胶质瘤手术风险的评估

Objective To elucidate the clinical significance of diffusion tensor imaging (DTI) mainly used for protecting neurological functions in patients with gliomas. Methods Thirty - eight patients with gliomas were recruited to undergo DTI test and assess the status of neurological functions before and after surgery. According to the relationships between gliomas and adjacent white matter(WM) tracts, DTI can be classfied as the following types : type Ⅰ - displacement; type Ⅱ - Infiltration; type Ⅲ - Disruption. The neurological functions before surgery were compared in three groups,as well as the change of neurological functions after surgery was also compared in three groups. Results There were 14 cases in type Ⅰ , 16 cases in type Ⅱ, and 8 cases in type Ⅲ. There were significant difference between DTI types and preoperative neurological functions, as well as between DTI types and the change of postoperative neurological functions ( P < 0. 05 ). Conclusions DTI allows to visualizate the relationships of gliomas and adjacent WM tracts, which represent the different growth patterns of gliomas. It is useful for neurosurgeons to select suitable surgical approaches and determine appropriate extent of resection.     

弥散张量成像对胶质瘤手术风险的评估

Objective To elucidate the clinical significance of diffusion tensor imaging (DTI) mainly used for protecting neurological functions in patients with gliomas. Methods Thirty - eight patients with gliomas were recruited to undergo DTI test and assess the status of neurological functions before and after surgery. According to the relationships between gliomas and adjacent white matter(WM) tracts, DTI can be classfied as the following types : type Ⅰ - displacement; type Ⅱ - Infiltration; type Ⅲ - Disruption. The neurological functions before surgery were compared in three groups,as well as the change of neurological functions after surgery was also compared in three groups. Results There were 14 cases in type Ⅰ , 16 cases in type Ⅱ, and 8 cases in type Ⅲ. There were significant difference between DTI types and preoperative neurological functions, as well as between DTI types and the change of postoperative neurological functions ( P < 0. 05 ). Conclusions DTI allows to visualizate the relationships of gliomas and adjacent WM tracts, which represent the different growth patterns of gliomas. It is useful for neurosurgeons to select suitable surgical approaches and determine appropriate extent of resection.     

弥散张量成像对胶质瘤手术风险的评估

Objective To elucidate the clinical significance of diffusion tensor imaging (DTI) mainly used for protecting neurological functions in patients with gliomas. Methods Thirty - eight patients with gliomas were recruited to undergo DTI test and assess the status of neurological functions before and after surgery. According to the relationships between gliomas and adjacent white matter(WM) tracts, DTI can be classfied as the following types : type Ⅰ - displacement; type Ⅱ - Infiltration; type Ⅲ - Disruption. The neurological functions before surgery were compared in three groups,as well as the change of neurological functions after surgery was also compared in three groups. Results There were 14 cases in type Ⅰ , 16 cases in type Ⅱ, and 8 cases in type Ⅲ. There were significant difference between DTI types and preoperative neurological functions, as well as between DTI types and the change of postoperative neurological functions ( P < 0. 05 ). Conclusions DTI allows to visualizate the relationships of gliomas and adjacent WM tracts, which represent the different growth patterns of gliomas. It is useful for neurosurgeons to select suitable surgical approaches and determine appropriate extent of resection.     

弥散张量成像对胶质瘤手术风险的评估

Objective To elucidate the clinical significance of diffusion tensor imaging (DTI) mainly used for protecting neurological functions in patients with gliomas. Methods Thirty - eight patients with gliomas were recruited to undergo DTI test and assess the status of neurological functions before and after surgery. According to the relationships between gliomas and adjacent white matter(WM) tracts, DTI can be classfied as the following types : type Ⅰ - displacement; type Ⅱ - Infiltration; type Ⅲ - Disruption. The neurological functions before surgery were compared in three groups,as well as the change of neurological functions after surgery was also compared in three groups. Results There were 14 cases in type Ⅰ , 16 cases in type Ⅱ, and 8 cases in type Ⅲ. There were significant difference between DTI types and preoperative neurological functions, as well as between DTI types and the change of postoperative neurological functions ( P < 0. 05 ). Conclusions DTI allows to visualizate the relationships of gliomas and adjacent WM tracts, which represent the different growth patterns of gliomas. It is useful for neurosurgeons to select suitable surgical approaches and determine appropriate extent of resection.     

Primary Osteolytic Intraosseous Atypical Meningioma with Soft Tissue and Dural Invasion: Report of a Case and Review of Literatures

Primary intraosseous meningioma is a rare tumor, and atypical pathologic components both osteolytic lesion and dura and soft tissue invasion is extremely rare. A 65-year-old woman presented with a 5-month history of a soft mass on the right frontal area. MR imaging revealed a 4 cm sized, multilobulated, strongly-enhancing lesion on the right frontal bone, and CT showed a destructive skull lesion. The mass was adhered tightly to the scalp and dura mater, and it extended to some part of the outer and inner dural layers without brain invasion. The extradural mass and soft tissue mass were totally removed simultaneously and we reconstructed the calvarial defect with artificial bone material. The pathological study revealed an atypical meningioma as World Health Organization grade II. Six months after the operation, brain MR imaging showed that not found recurrence in both cranial and spinal lesion. Here, we report a case of primary osteolytic intraosseous atypical meningioma with soft tissue and dural invasion.     

“脑膜尾征”与脑膜瘤部位及其病理类型的关系

目的分析脑膜瘤MRI上"脑膜尾征"形态学表现与脑膜瘤部位及其病理类型的关系。方法回顾性分析我院自2005年1月至2009年10月资料齐全的135例经手术病理证实的脑膜瘤患者的临床资料,主要包括MRI表现和病理学结果 ,重点分析其"脑膜尾征"形态与肿瘤部位及其病理类型的关系。结果 75.56%的脑膜瘤在MRI T_1WI增强像上表现有"脑膜尾征",其形态上分为单尾、双尾和多尾。不同部位脑膜瘤和不同病理类型的脑膜瘤"脑膜尾征"形态学特点有所不同。结论脑膜瘤"脑膜尾征"的形态与局部硬膜组织结构和肿瘤病理类型有关系。明确认识此种关系对术前提高脑膜瘤良恶性诊断水平,术中选择正确的切除方式,树立正确的手术理念有一定指导意义。     

凸面脑膜瘤脑膜尾征的临床意义探讨

目的探讨凸面脑膜瘤脑膜尾征的临床意义。方法对43例具有脑膜尾征的凸面脑膜瘤的基底缘及周围至少2．0cm硬脑膜．分段行光镜和电镜病理学检查。结果4l例（95．3％）肿瘤周围硬脑膜可见血管扩张或增生，40例（93．0％）肿瘤周围硬脑膜有纤维结缔组织增生：16例（37．2％）硬脑膜被肿瘤细胞侵袭，其中8例硬脑膜在肿瘤基底缘即0位置可见到肿瘤细胞侵袭，6例在0．1～0．5cm范围，2例在0．6～1．0cm范围仍见到肿瘤细胞侵袭，而瘤周硬脑膜〉1．0cm范围未见肿瘤侵袭。结论脑膜尾征对应硬脑膜的组织构成有三种：肿瘤细胞浸润，纤维结缔组织增生，及丰富的血管和血管扩张。肿瘤细胞侵袭脑膜尾征对应硬脑膜主要集中于0～0．5cm范围，少部分集中在0．6～1cm范围，无〉1．0cm者。     

良性脑膜瘤术后复发及预后相关因素分析

目的探讨性别、年龄、手术切除程度、肿瘤周围水肿、有无“脑膜尾征”、肿瘤形状、肿瘤部位、肿瘤大小、有无钙化、肿瘤界限等因素与良性脑膜瘤术后复发及预后的关系。方法对72例经术后病理证实为良性脑膜瘤患者进行回顾性分析。结果手术切除程度、肿瘤周围水肿、有无“脑膜尾征”、肿瘤形状、肿瘤部位、肿瘤大小、有无钙化、肿瘤界限等因素与良性脑膜瘤术后复发及预后显著相关。结论尽可能彻底的手术方式有助于减少术后良性肿瘤的复发，手术切除程度、肿瘤周围水肿、有无“脑膜尾征”、肿瘤形状、肿瘤部位、肿瘤大小、有无钙化、肿瘤界限等因素可做为良性脑膜瘤的术后复发的预测指标．并成为制定术后综合治疗方案的依据．     

Lymphoplasmacyte‐rich meningioma: A convexity mass with regional enhancement in the adjacent brain parenchyma

Lymphoplasmacyte‐rich meningioma (LPM) is a rare, benign variant of meningioma, characterized by massive inflammatory cell infiltration and a variable proportion of meningothelial tumorous elements. Here we report the clinicopathological features of an LPM located at the right frontal convexity in a 37‐year‐old woman. The patient had suffered an initial generalized tonic‐clonic seizure when she was 32 weeks pregnant. The lesion exhibited low intensity on T1‐weighted MRI and high intensity on T2‐weighted images, with surrounding parenchymal edema. The mass exhibited gadolinium enhancement with dural tail signs. Moreover, multiple foci of linear enhancement spreading through the sulci and into the nearby brain parenchyma were evident. At 1 month after parturition, en bloc removal of the mass, the attached dura mater and adjacent brain tissue was performed. Histologically, the mass located in the subdural space was composed of a mixture of B‐ and T‐lymphocytes and plasma cells. Within the mass, multiple small lobules of meningothelial cells showing immunoreactivity for epithelial membrane antigen and vimentin were observed. The inflammatory cells had also infiltrated the subarachnoid and Virchow‐Robin spaces, and the dura mater. The cerebral cortex showed ischemic changes, but no tumor cell invasion. On the basis of these histological features, the lesion appeared to be LPM with an inconspicuous meningothelial component and extensive inflammatory infiltration. This case appears to provide useful information on the pathogenesis of this variant.     

Two cases of primary osteolytic intraosseous meningioma of the skull metastasizing to whole skull and the spine

We report here two cases of primary intraosseous meningioma with aggressive behavior. A 68-year-old man presented with a one year history of a soft, enlarging mass in the right parietal region. Magnetic resonance image (MRI) revealed a 6 cm sized, heterogeneously-enhancing, bony expansile mass in the right parietal bone, and computed tomograph (CT) showed a bony, destructive lesion. The tumor, including the surrounding normal bone, was totally resected. Dural invasion was not apparent. Diagnosis was atypical meningioma, which extensively metastasized within the skull one year later. A 74-year-old woman presented with a 5-month history of a soft mass on the left frontal area. MRI revealed a 4 cm sized, multilobulated, strongly-enhancing lesion on the left frontal bone, and CT showed a destructive lesion. The mass was adhered tightly to the scalp and dura mater. The lesion was totally removed. Biopsy showed a papillary meningioma. The patient refused adjuvant radiation therapy and later underwent two reoperations for recurred lesions, at 19 and at 45 months postoperative. The patient experienced back pain 5 years later, and MRI showed an osteolytic lesion on the 11th thoracic vertebra. After her operation, a metastatic papillary meningioma was diagnosed. These osteolytic intraosseous meningiomas had atypical/malignant pathologies, which metastasized to whole skull and the spine.     

Dural plasmacytoma mimicking meningioma in a patient with multiple myeloma.

Apart from calvarial infiltration, intracranial involvement in multiple myeloma is uncommon. Diffuse leptomeningeal invasion with or without parenchymal involvement is most common. Dural infiltration without involvement of the parenchyma, leptomeninges or skull is rare. The differential diagnosis of a dural plasmacytoma includes meningioma, which has a similar MRI appearance, metastasis, lymphoma and sarcoma of the dura mater. We present a patient with multiple myeloma presenting with an intracerebral mass mimicking a meningioma on MRI. Multiple myeloma had been diagnosed seven years previously. The patient presented with headache and speech disturbance 12 months after autologous peripheral stem cell transplantation for recurrence of multiple myeloma. MRI revealed a left temporal extra-axial mass with a dural tail mimicking meningioma. Histopathological examination of the mass after excision showed multiple myeloma immunopositive for IgG, kappa light chain and CD38. There was no recurrence after postoperative radiotherapy. Plasmacytoma should be considered in the differential diagnosis of a solitary dural mass, particularly in a patient with multiple myeloma.     

Local versus diffuse recurrences of meningiomas: factors correlated to the extent of the recurrence

OBJECTIVE: The aim of this study is to evaluate the factors correlated with the different patterns (local, peripheral and diffuse) of meningioma recurrence. MATERIAL AND METHODS: 55 patients with benign (WHO I) meningiomas which recurred after seemingly complete removal were reviewed; 40 (Group I) had local or peripheral recurrences (< 3 cm from the initial dural attachment) and 15 (Group II) had distant and diffuse recurrences. Patient age and sex, tumor location, interval of recurrence, tumor shape, type of brain-tumor interface, histological subtype, mitotic index (MI) and progesterone receptor (PR) expression of the initial tumor, histological WHO Grade of the recurrent tumor and patient outcome were analyzed and correlated with the pattern of recurrence. RESULTS: Flat-shaped meningiomas with large dural attachment showed a significantly higher rate of diffuse recurrences than round tumors, whereas the brain-tumor interface and the tumor location were not relevant (excepting the lack of convexity meningiomas in the group of diffuse tumors). There were no significant differences of histology, MI and PR expression of the initial tumor and histological grade of the recurrent tumor between the two groups. CONCLUSIONS: The different patterns of meningioma recurrences (local, peripheral, diffuse) are not correlated with the tumor location and histology and do not represent a different biological tumor progression. We agree that most unexpected extensive recurrences result from a more extensive microscopic dural involvement.     

MRI of aggressive meningiomas.

The authors have attempted to establish by MRI morphological criteria for the so-called "aggressive" intracranial meningiomas. The MRI features of 20 meningiomas histologically aggressive (numerous mitoses and small necrotic foci) or malignant (same plus invasion of the subjacent brain tissue) were compared with those of a control population of 26 patients with benign meningioma. The site of the tumour and its histological type had little predictive value, but there was a remarkably high proportion of male patients in the group with aggressive meningioma (9/20 versus 2/26). More than other varieties, aggressive meningiomas frequently emitted, on both T1- and T2-weighted sequences, a heterogeneous signal due to a necrotic focus (P less than 0.01). The high-intensity signal observed on T2-weighted sequences (11/20) was suggestive of syncitial or angioblastic meningioma. Cystic meningiomas were present in virtually equal proportions (3/20 versus 3/26) in the two populations and could raise problems concerning the diagnosis of nature, especially when intraventricular. Gadolinium injection provided further evidence of aggressiveness, such as irregular tumour outline or even contrast enhancement of brain tissue in malignant cases (3/4), but enhancement of the dura mater was equally frequent in both groups (P greater than 0.2). Massive peritumoral oedema was significantly more frequent in aggressive melanomas (P less than 0.01).     

非典型性脑膜瘤与良性脑膜瘤MRI征象的对比分析

目的 对比分析非典型性脑膜瘤与良性脑膜瘤的MRI征象特点,提高对非典型性脑膜瘤的认识。方法 回顾性分析经病理证实的37例非典型性脑膜瘤与288例良性脑膜瘤的MRI征象。结果 非典型性脑膜瘤直径>6.5 cm比例、肿瘤呈分叶型比例、瘤脑界面不清晰比例、重度瘤周水肿比例、邻近骨质改变比例均明显高于良性脑膜瘤（P<0.05）。多因素Logistic回归分析显示,肿瘤较大及瘤脑界面不清晰为非典型性脑膜瘤的可能性显著增加,肿瘤大小每增加1.5 cm,非典型性脑膜瘤的概率是良性脑膜瘤的1.507倍,瘤脑界面不清晰为非典型性脑膜瘤的概率是良性脑膜瘤的2.605倍。结论 肿瘤大小及瘤脑界面对于非典型性脑膜瘤与良性脑膜瘤的鉴别诊断具有重要价值。