血管瘤型脑膜瘤MRI表现及病理学基础

目的探讨血管瘤型脑膜瘤的MRI特征及病理学特点。方法回顾分析25例经手术和病理证实的血管瘤型脑膜瘤的影像资料,对其MRI特点及病理基础进行分析。结果肿瘤位于大脑镰旁15例,桥小脑角区3例,小脑幕旁5例,鞍结节2例,影像表现为边界清楚的实性软组织肿块;大部分病变T1WI呈稍低信号,T2WI呈高信号,瘤内可见流空血管,占位效应明显而水肿轻;肿瘤内部信号均匀;增强扫描实性肿瘤均非常显著强化。结论血管瘤型脑膜瘤发病率较低,但其MR表现具有一定的特征性,MRI检查有利于肿瘤术前定位及定性诊断。     

恶性脑膜瘤的影像学特征和病理学改变

目的 探讨恶性脑膜瘤影像学特征和病理学改变。方法 回顾性分析11例恶性脑膜瘤患者的影像学表现和病理学改变的资料。结果 影像学检查病灶密度或信号不均匀者9例，不均一强化者6例，边缘不规则呈分叶状或结节状者8例，境界模糊者7例，“硬膜尾征”者7例，颅骨破坏者1例。病理学检查肿瘤坏死、囊变者9例，7例境界模糊者镜下有脑浸润，7例“硬膜尾征”者镜下有硬膜肿瘤细胞浸润。结论 恶性脑膜瘤CT、MRI表现有一定特异性，认识其影像学特征可以减少术前误诊，有利于临床综合治疗和预后判断。     

镰旁脑膜瘤的MRI影像学表现与病理意义

目的分析镰旁脑膜瘤的MRI征象与病理,以期提高其临床诊治水平。方法 73例镰旁脑膜瘤患者行MRI检查。将位置、大小、形状、边缘、水肿、信号、强化方式等影像特征、病理特点综合分析。结果除宽基底、脑膜尾征、假包膜等一般脑膜瘤的MRI表现外,还发现了如下不常见MRI表现:囊变2例,出血2例,钙化5例,颅骨受侵4例及肿块跨越征2例,病理可见相应表现。结论大脑镰旁脑膜瘤具有囊变、出血、钙化、颅骨受侵及肿块跨越征等不常见MRI征象。熟悉这些不典型表现与手术、病理综合分析,在肿瘤的诊断、鉴别诊断与治疗均具有很大价值。     

微囊型脑膜瘤的MRI表现及临床病理对照研究

目的探讨微囊型脑膜瘤的MRI表现及其诊断价值,并与病理相对照。方法回顾性分析12例经病理证实的微囊型脑膜瘤影像学资料及病理资料。结果额叶6例(左4例,右2例),颞叶2例,顶叶大脑镰旁2例,右侧桥脑小脑角区1例,鞍区1例;12例中9例平扫T1WI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;12例病变中5例可见脑膜尾征;10例可见中、重度瘤周水肿;镜下组织中见瘤细胞排列疏松,呈微囊状。结论微囊型脑膜瘤是颅内少见肿瘤,MRI表现有一定特点:T1WI呈低信号,T2WI呈明亮高信号,瘤周水肿明显,增强后呈明显强化,MRI有助于对其诊断和鉴别诊断。     

鞍结节脑膜瘤的磁共振成像诊断:59例报道

目的::探讨鞍结节脑膜瘤的磁共振成像(magnetic resonance imaging,MRI)影像学特征及其诊断价值。方法::回顾性分析1995年1月—2015年12月经术后病理证实的59例鞍结节脑膜瘤患者的术前MRI影像学特征。结果::59例鞍结节脑膜瘤患者中,男性15例,女性44例。所有59例鞍结节脑膜瘤的基底均位于鞍结节或鞍隔的硬膜;MRI平扫T1加权像(weighted image,WI)均呈等信号或略低信号,T2WI均呈等信号或略高信号;57例鞍结节脑膜瘤的MRI增强扫描图像呈明显的均匀强化,2例呈不均匀强化;45例可见"脑膜尾征"。结论::MRI检查在鞍结节脑膜瘤的定位和定性诊断中显示出明显的优势,可以为手术方式的选择、肿瘤切除程度的评估以及手术风险的预测提供重要指导。     

非典型性和恶性脑膜瘤的CT、MRI诊断

目的探讨非典型性和恶性脑膜瘤的CT、MRI表现,提高术前诊断率。方法收集经病理诊断证实为非典型或恶性脑膜瘤患者36例,术前均进行CT、MRI平扫和增强检查。结果 CT表现为肿瘤呈混杂、等、低密度影,缺少钙化,可伴有出血,骨质呈破坏性改变;MRI T1WI均呈不规则混杂信号,以等、低信号为多见,T2WI以高等混杂信号为多见。增强扫描,肿瘤多显著强化,且以不均匀强化常见,肿瘤形态多不规则,呈分叶状,边界模糊。结论 CT、MRI检查能充分显示肿瘤信号、边界、囊变、坏死、钙化、瘤周水肿、瘤内出血及肿瘤血供等情况,对非典型性或恶性脑膜瘤进行准确的诊断和术前评估。     

颅内原发黑色素瘤的CT和MRI诊断

目的 探讨颅内黑色素瘤的CT和MRI影像学表现特征,进一步提高对本病的认识.方法 对4例颅内黑色素瘤的CT和MRI表现,结合文献进行回顾性分析,全部病例均CT、MRI平扫,其中3例CT进行增强,2例MRI进行增强.结果 单发肿瘤和多发肿瘤各2例,CT表现为类圆形高密度影3例,低密度影1例;4例MRI检查,肿瘤呈短T1短T2信号2例,短T1长T2信号1例, 等T1短T2信号1例,肿瘤信号不均匀,边缘清楚,增强后肿瘤呈均匀性强化.结论 肿瘤内特征性的短T1短T2信号对术前确诊具有决定意义,是颅内黑色素瘤的最佳影像学检查方法 ,而CT高密度影应与出血性脑膜瘤等相鉴别.     

恶性脑膜瘤的临床特点及诊疗体会

目的：总结恶性脑膜瘤的临床特点及诊疗体会。方法回顾性分析解放军总医院收治的27例经病理证实为恶性脑膜瘤（ WHOⅢ级）患者的临床表现、诊治经过、术后辅助治疗及预后等资料,窦镰旁恶性脑膜瘤7例,大脑凸面恶性脑膜瘤8例,蝶骨嵴恶性脑膜瘤5例,岩斜区等其他部位恶性脑膜瘤7例,其中肿瘤直径＞5 cm 19例。主要影像学特点为磁共振增强扫描呈明显不规则强化,周围水肿带明显。结果27例恶性脑膜瘤病例中,间变型恶性脑膜瘤18例,横纹肌样恶性脑膜瘤7例,乳头型恶性脑膜瘤2例。患者均行显微手术治疗,无死亡病例。按照Simpson标准,SimpsonⅠ级切除者11例,SimpsonⅡ级切除者6例,SimpsonⅢ级切除者6例,SimpsonⅣ级切除者4例。随访平均37．2个月,Ⅰ～Ⅱ级切除者7例（41．2％）出现复发,Ⅲ～Ⅳ级切除者患者均复发（100％）。其中,术后放疗者13例,未行放疗者14例,复发率分别为61．5％及78．6％。结论恶性脑膜瘤易复发,治疗首选显微外科全切除肿瘤,并处理硬膜及受累颅骨,术后应辅以放疗。     

大脑镰旁脑膜瘤的MRI诊断和显微手术治疗

目的探讨大脑镰旁脑膜瘤的MRI特点和显微手术技巧。方法回顾性分析24例大脑镰旁脑膜瘤的诊断和治疗。结果24例MRI检查均有不同程度瘤周水肿,T1加权像呈稍低或等密度信号,T2加权像呈稍高或等密度信号,增强扫描肿瘤明显强化,11例有“硬膜尾征”。3例颅骨侵犯。所有患者均采用显微手术治疗,SimpsonⅠ级切除19例,Ⅱ级切除5例。随访10个月至8年,无肿瘤复发。结论MRI是目前诊断大脑镰旁脑膜瘤首选的方法,对手术入路的选择及术中并发症的预防有指导意义。显微手术明显提高大脑镰旁脑膜瘤的全切除率,减少残死率。     

恶性脑膜瘤的影像学特点和显微手术治疗

目的 探讨恶性脑膜瘤的影像学特点和显微手术治疗。方法回顾性分析17例恶性脑膜瘤的影像学表现和治疗经过。结果影像学检查17例均有不同程度瘤周水肿,13例病灶密度或信号不均匀,12例不均一强化,7例有“硬膜尾征”,4例颅骨浸润。本组均无钙化。17例均行显微手术治疗。初次手术Simp-sonⅠ级切除11例,Ⅱ级切除3例,Ⅲ级切除3例;再次手术行SimpsonⅡ级切除9例,Ⅲ级切除3例;5例第三次手术,Simpson Ⅲ级切除2例,Ⅳ级切除3例;其中1例第四次手术行Simpson Ⅳ级切除。本组无手术死亡。结论恶性脑膜瘤影像学有一定特征,认识其特征可减少术前误诊。手术是治疗恶性脑膜瘤的主要手段．显微手术全切除肿瘤是预防复发的关键。     

Magnetic resonance imaging features of cystic meningiomas. Report of four cases

Four cases of cystic meningioma are reported, and the imaging features and diagnostic pitfalls of cystic meningiomas are reviewed. Cystic meningiomas are infrequent tumors and remain difficult to diagnose in spite of advanced imaging techniques. Our patients were between 15 and 58 years of age, and underwent CT and MR imaging. In all the four cases, the meningiomas were supratentorial and included Nauta type I, type II and type III tumors.     

Microcystic meningiomas: comparison of histology and computed tomography

INTRODUCTION: Microcystic meningiomas are defined by large vacuolated and stellate shaped cells. We recently examined a microcystic meningioma mimicking a malignant tumor on computed tomography (CT). The aim of the current study was to compare the radiological features of microcystic meningiomas with their histological patterns. METHODS: We have diagnosed 7 intracranial microcystic meningiomas among 204 meningiomas registered in the files of our Department of Pathology from 1994 to 2001. All CT scans performed before surgery were reviewed. RESULTS: Three of the microcystic meningiomas appeared as entirely microcystic tumors. Two of them were homogeneously hypodense or isodense on CT scan. The third mening was heterogeneous, containing some blood. The histologic pattern of the 4 other meningiomas showed microcystic tumor cells associated with meningothelial or fibrous tumor cells. These meningiomas were heterogeneous on CT scan. All meningiomas seemed to be connected to the dura mater. Three tumors were strongly and homogeneously enhanced after contrast media injection while 3 others were heterogeneously enhanced. No enhanced CT scan was available for 1 case. Astrocytomas were incorrectly diagnosed by CT scan in the 3 heterogeneously enhanced tumors. Meningiomas were correctly diagnosed in the 3 strongly enhanced tumors. CONCLUSION: The presence of microcystic tumour cells in meningiomas often results in erroneous diagnosis on CT scan, particularly for those which are heterogeneously enhanced. In these cases, a diagnosis of astrocytoma is often made.     

Intraventricular meningioma with drop metastases and subgaleal metastatic nodule.

We report a case of malignant intraventricular meningioma with CSF drop metastases and an implantation metastatic subgaleal nodule in a 53-year-old woman. Malignant intraventricular meningiomas are rare with only seven cases being reported in the literature. These tumours can be very aggressive and one should consider immediate postoperative radiotherapy.     

Imaging appearances of meningeal melanocytoma

Meningeal melanocytoma is an uncommon, benign melanocytic tumour of the meninges. Only 15 cases have been reported to date. We present the MR and CT appearance of a case of compressive myelopathy due to cervical meningeal melanocytoma. Careful analysis of the imaging features, as illustrated in the present case, allows a preoperative diagnosis. The differential diagnosis includes malignant melanoma and melanocytic meningioma.     

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).     

Subfrontal approach in sellar and suprasellar lesions

A variety of mass lesions are placed in and around of the sella turcica. Although their common location these lesions have distinguishing features and different approaches can be selected. There are conventional transcranial and sophisticated skull base approaches. We report our experience with a subfrontal route to the sellar region. Between February 1997 and March 1998, 19 tumors placed around the sella have been treated surgically by this method. Eleven of them were pituitary tumors, 3 were craniopharyngeomas, 2 were meningiomas, and 1 was germinoma. Total removal was achieved in 17 cases. There was not operative mortality. Postoperative complications included twelve cases of unilateral anosmia and four cases of transitory diabetes insipidus. Progressive stroke occurred in one patient. These results stress the importance of the subfrontal approach to reach such lesions in sellar region.     

经鼻-蝶窦手术路径的体表定位及鼻-蝶窦区的三维CT影像解剖

目的 探讨三维螺旋CT在鼻-蝶鞍区影像解剖及经鼻-蝶窦垂体瘤手术入路的鞍底定位中的应用.方法 回顾性分析29例鼻-蝶鞍区螺旋CT扫描数据,以3D重建和剪切技术重建和观察鼻-蝶鞍区的3D解剖结构.分析鼻尖-耳轮上缘连线(鼻-耳轮线)与鞍底的关系.对14例垂体瘤患者术前、术后行螺旋CT扫描和重建,评估3D - CT和鼻-耳轮线在经鼻-蝶窦垂体瘤术前规划和术中鞍底定位中的可行性.结果 鼻-耳轮线在所有的研究对象中均与蝶窦相交,其中与鞍底相交者12例占42％.鞍底-斜坡交点至鼻-耳轮线的垂直距离是(3.6±1.8)mm.3D - CT能清晰地显示鼻-蝶鞍区的解剖结构,包括蝶窦及其分隔、颈动脉和视神经管隆起、鞍底等.为模拟手术入路和术中鞍底定位提供重要信息.结论 3D - CT技术可获得鼻-蝶鞍区高清晰度的三维空间解剖图像,有助于经鼻-蝶窦垂体瘤手术方案的制定和术中蝶窦和鞍底的定位.鼻-耳轮线可作为经鼻-蝶窦垂体瘤手术路径的体表定位.     

恶性脑膜瘤临床,影像与病理特征

目的 探讨恶性脑膜瘤的临床影像与病理特征。方法 复习１９７９￣１９９９年经治的１０例恶性脑膜瘤,应临床表现、影像、肿瘤类型病理检查、复发、放射治疗及随访进行研究。结果 全组病例均属恶性脑膜瘤,除一例存活外均已死亡。结论 ＣＴ对诊断恶性脑膜瘤有其临床意义。如肿瘤组织学表现有坏死、脑浸润、间变、有丝分裂增多、颅外转移、临床过程短暂或短期复发应归属恶性,特别是血管外皮细胞脑膜瘤应属高危性。     

High-dose radiation-induced meningiomas following acute lymphoblastic leukemia in children

The authors review three personal cases of patients who developed cerebral meningiomas following high-dose radiotherapy for acute lymphoblastic leukemia. Two patients were female and one male. Their ages when the leukemia appeared were between 11 and 15 years. All patients were treated with a course of prophylactic irradiation to the neuraxis for a total dose of 24 Gy. After an average interval of 10.4 years, all three patients presented a meningioma; histologically, one was meningothelial and two were fibrous. All three meningiomas presented atypical features. At follow-up 1, 4, and 4 years respectively after surgery, none of these patients presents neurological deficits or neuroradiological signs of recurrence. Forty-nine cases of high-dose radiation-induced meningioma are also reviewed.     

Difficulties in diagnosis of intracranial meningiomas by computed tomography.

The false positive and false negative computed tomography diagnoses of meningioma made using EMI 1010 and 5005 machines on a consecutive series of patients seen over a period of four years are described. About 1.2% of intracranial meningiomas were not detected on initial CT scan, 6.6% were misdiagnosed including 5.2% which were thought to be malignant lesions; in 9.4% of the cases identified as meningioma another diagnosis was subsequently established of which 6.3% were malignant.