视神经肿瘤的MRI诊断

目的:探讨视神经肿瘤的MRI表现。方法:回顾了18例经MRI检查并经临床病理确诊的视神经肿瘤的病例。结果:视神经脑膜瘤8例,表现为视神经增粗1例,梭形肿块5例,软组织肿块2例。MR T1WI呈等或稍低信号,T2WI呈高信号。视神经胶质瘤6例,表现为视神经梭形增粗2例,椭圆形肿块4例,MR T1WI呈等信号,T2WI呈高信号。视神经转移瘤4例,3例为视网膜母细胞瘤累及视神经,MRI表现为眼球内病变侵犯视神经和视交叉,T1WI呈稍低信号,T2WI呈稍高信号;1例为乳腺癌转移至视神经,MRI表现为视神经椭圆形增粗,T1WI呈等信号,T2WI呈高低混杂信号。结论:MRI是检查和诊断视神经肿瘤的重要检查手段,对大多数病变可做出明确诊断。     

眼眶肿瘤的CT、MRI诊断

目的:探讨眼眶肿瘤的CT、MRI表现及其诊断价值。材料和方法:回顾性分析38例经临床病理证实的眼眶肿瘤的CT、MRI表现。结果:视神经鞘脑膜瘤9例,表现为视神经增粗1例,梭形肿块6例和软组织肿块2例,CT为软组织密度;T1WI呈等或稍低信号,T2WI呈高信号。视神经胶质瘤6例,表现为视神经弥漫性增粗2例,椭圆形肿块4例;CT为软组织肿块;T1WI呈等信号,T2WI呈高信号。海绵状血管瘤12例,CT示类圆形稍高于脑组织密度影,T1WI呈稍低信号,T2WI明显高信号。恶性淋巴瘤4例,均为弥漫性病变,CT示长条状软组织肿块,T1WI呈等信号,T2WI呈高信号。神经鞘瘤3例;CT表现密度不均肿块,T1WI呈稍低信号,T2WI呈稍高信号,信号不均匀。转移瘤4例,其中转移性腺样囊性癌1例,乳腺癌眶内转移3例。结论:CT、MRI是发现和诊断眼眶肿瘤的重要检查手段,对大多数肿瘤可以做出明确诊断。     

脑内原发性淋巴瘤CT及MRI诊断

目的：探讨CT和MR／对脑内原发淋巴瘤的诊断价值。方法：对12例经手术和病理证实的脑内淋巴瘤的CT和MR／影像学表现进行回顾性分析。结果：单发10例、多发2例，CT表现多为等密度或稍高密度肿块。MR／表现T1WI呈等或稍低信号，T2WI多为稍高信号，CT和MR／增强扫描多为均匀强化。结论：脑内原发淋巴瘤少见，影像学表现与颅内其它肿瘤互相重叠，CT和MR／平扫和增强扫描的应用有助于脑内淋巴瘤的诊断和鉴别诊断。     

鼻咽部血管纤维瘤的影像学诊断价值

目的：探讨鼻咽部血管纤维瘤影像学的价值。方法：回顾分析经手术病理证实的血管纤维瘤的CT、MRI、DSA特征，CT检查13例，MRI4例和DSA3例，同时完成2项或3项检查分别为4例和3例。结果：13例均显示出病变的部位及范围，CT平扫示软组织块为等密度或稍高密度。MRI示肿块T1WI呈等于或略高于肌肉信号，T2WI呈高信号。肿块增强扫描明显强化，CT强化密度曲线呈速升缓降型；MRI信号增强率升高。3例DSA显示供血情况以及营养血管的特征。结论：血管纤维瘤有特征性的CT和MRI表现，CT动态扫描、MRI增强率的表达及DSA有助于诊断和鉴别诊断。     

眼眶内肿块的鉴别诊断(附78例使用表面线圈的高分辨力MRI检查报告)

在过去的十年中，MRI已成为诊断眼眶肿块的首选检查方法。目的：评估眼眶内肿块MRI鉴别诊断的标准。方法：对78例跟眶内肿块患的MRI检查资料进行回顾性研究，所有检查均使用表面线圈以获得高的空间分辨力。观察增强前后T1WI及T2WI的信号表现及肿瘤特征(如形状、大小、部位、边界及浸润)。所有病例均经手术切除(18例)或活检(22例)的组织病、其它的影像学方式(13例)或临床病程(25例)证实。     

虹膜睫状体肿瘤的MRI诊断探讨

目的 分析虹膜睫状体肿瘤的MRI表现,评价虹膜睫状体肿瘤MRI诊断价值.方法 回顾分析8例虹膜睫状体肿瘤MRI表现;8例均行MRI平扫,4例行MRI增强.结果 3例睫状体上皮腺瘤MRI均表现为与晶状体相连的类圆形软组织结节,T1WI和T2WI呈中等信号,MRI增强结节强化.2例睫状体黑色素瘤MRI表现为虹膜睫状体区不规则软组织结节,T1WI呈高信号,T2WI呈低或中等信号.1例虹膜淋巴瘤表现为晶状体、虹膜睫状体和前房内不规则软组织肿块,T1WI和T2WI均呈中等信号.1例虹膜血管平滑肌瘤表现为眼环前部类圆形结节,T1WI和T2WI均呈中等信号,MRI增强结节强化,同时合并视网膜脱离.1例睫状体神经纤维瘤MRI表现为晶状体附近类圆形结节,形状规则、边缘光滑,T1WI和T2WI呈均匀中等信号.结论 MRI可以显示虹膜睫状体肿瘤的大小、部位和种类,可以作为虹膜睫状体肿瘤影像学检查的主要方法.     

椎管硬膜外原发肿瘤的MRI诊断

目的：探讨MRI对椎管硬膜外原发肿瘤的诊断价值。资料与方法：分析经手术病理证实的16例硬膜外原发肿瘤的MRI表现，结果：MR定位正确率为100％，5例血管脂肪瘤中4例以脂肪信号为主，瘤体内血管成分表现为条带状T2WI低信号，T2WI高信号，3例海绵状血管瘤呈椭圆形，T1WI呈低信号，T2WI呈高信号，注射对比剂后可明显均匀强化，1例血管瘤MR表现与海绵状血管瘤相似。4例恶性淋巴瘤T1WI呈等低信号，T2WI呈等或稍高信号，可中度或显著强化，有2例通过椎间孔向椎旁生长，1例破坏邻近椎体形成巨大软组织肿块，3例脊膜瘤呈宽基底附着于硬膜，T1WI呈中等信号，T2WI呈等信号，瘤体明显的均匀强化，邻近硬膜增厚，结论：根据椎管硬膜外原发肿瘤的MR表现，可准确定位并可推测其病理类型。     

卵巢少见原发性肿瘤的MR表现

目的探讨卵巢少见原发性肿瘤的MR表现及特征,并与病理学对照,以提高对该类疾病的诊断及鉴别诊断能力。方法回顾性分析经手术病理证实的6例卵巢少见原发性肿瘤的MR表现并复习相关文献。结果卵巢淋巴瘤1例,表现双侧附件区T1WI等信号T2WI稍高信号软组织肿块影,信号均匀,边缘光滑。无性细胞瘤2例,表现为盆腔巨大实性软组织肿块影,呈T1WI等、低信号,T2WI呈等-稍高信号,中心可见少量囊变坏死区。卵巢wolffian管瘤1例,表现为不规则浅分叶状软组织肿块影,边界清晰,呈T1WI等略低信号T2WI等、高信号影。卵巢Brener瘤1例,盆腔内软组织肿块影,呈T1WI等信号T2WI略低信号,病灶中心可见斑片状T1WI低信号T2WI低信号提示钙化灶。CT平扫表现为类圆形实性肿块,边界清晰,瘤体内见不规则斑片状钙化。硬化性间质瘤1例,表现为盆腔内巨大软组织肿块影,呈T1WI高低混杂信号T2WI高低混杂信号影。结论 MRI对卵巢少见原发肿瘤的定位以及定性有着无可替代的优势,是目前最为可靠的术前检查手段,能充分显示病变与周围组织的关系,但最后确诊仍须结合临床及完整的病理资料分析。     

颅内原发性恶性淋巴瘤的CT和MRI诊断

目的:探讨颅内原发性恶性淋巴瘤的CT、MRI表现及其临床诊断价值。方法:对29例经手术和病理证实的颅内恶性淋巴瘤患者的CT、MRI检查资料进行回顾性分析。结果:CT平扫肿瘤呈边缘相对锐利的等、高密度灶;MR扫描T1WI呈等或稍低信号灶,T2WI呈等或稍高信号灶;增强扫描肿瘤常见均匀强化,呈“握拳样”或“团块样”;肿瘤常常位于脑表面或近中线部位;多数肿瘤轻至中度水肿,占位效应轻。结论:颅内原发性恶性淋巴瘤的影像学表现与某些神经系统病变有类似和重叠之处,但通过认真地分析影像表现并结合活检结果,CT、MR扫描有利于该病变的诊断与鉴别诊断,并减少误诊。     

腮腺间隙原发病变的CT和MRI影像诊断及鉴别诊断

目的:提高腮腺间隙原发病变影像诊断及鉴别诊断能力。方法:回顾性分析32例腮腺间隙原发病变的影像特征,包括25例良性肿瘤及肿瘤样病变,7例原发恶性肿瘤。结果:CT和MRI能显示病变累及的范围。多形性腺瘤局部含有丰富的纤维粘液样基质,在T2WI上呈高信号以及增强后明显强化。腮腺腺淋巴瘤多位于腮腺浅叶下极,表现为边界清楚的双侧或单侧多发的囊实性肿瘤,增强扫描早期明显强化。基底细胞瘤呈T1WI、T2WI低信号,增强后呈早期及延迟强化。1例血管淋巴管瘤和1例淋巴管瘤表现边界较清的弥漫性软组织肿块,具有"钻缝生长"特征。神经鞘瘤在MRI上信号不均匀,可见斑片状T2高信号,增强后不均匀明显强化。恶性肿瘤边界不清,浸润生长,T2WI呈低信号,增强后不均匀强化。其它病变缺乏影像学特征。结论:腮腺间隙原发病变有一定的临床及影像特征,术前CT和/或MRI检查,有利于病变的诊断、鉴别诊断和治疗方法的选择。     

葡萄膜黑色素瘤的MRI诊断

目的探讨MRI对葡萄膜黑色素瘤的诊断价值。资料与方法对35例葡萄膜黑色素瘤患者行MRI横断面、冠状面、斜矢状面平扫及增强扫描。结果35例黑色素瘤患者中27例在T1WI表现为高信号,8例为等信号,T2WI上均为低信号,增强后为中度至明显强化。21例继发的视网膜脱离在T1WI上为高信号,T2WI上为等或高信号,无强化。结论MRI可对肿瘤进行精确定位,同时能显示肿瘤的大小和信号特征,有助于对葡萄膜黑色素瘤的诊断及鉴别诊断。     

脑原发淋巴瘤的MRI分析

目的：分析脑原发淋巴瘤的MRI影像学表现特征,以加强对该肿瘤影像学表现的认识。方法：对经病理证实的11例脑原发淋巴瘤的临床和MRI资料进行回顾性研究,分析肿瘤的部位分布、形态和肿瘤的信号特征。结果：11例肿瘤中,顶叶4例,额叶3例．胼胝体及透明隔区3例,眼球及海绵窦区1例。全部肿瘤呈实质性肿块,7例T1WI呈稍低信号．T1WI呈稍高信号;4例T1WI和T2WI呈等信号;增强后11例肿瘤均呈明显均匀性强化。结论：脑原发淋巴瘤多起源于脑实质和胼胝体区．肿瘤通常没有囊变和坏死,增强后呈明显强化是其特征。     

Periosteal chondroma: MR characteristics

PURPOSE: The purpose of this study was to describe the MR characteristics of periosteal chondroma. METHOD: MR images of 12 proven cases of periosteal chondroma were analyzed with reference to tumor morphology and size. MR features were correlated with radiographic and pathologic findings. RESULTS: Tumor size ranged from 1 to 7 cm in maximum diameter with a mean value of 2.6 cm. On MR images, a soft tissue mass at the bone surface with pressure erosion of adjacent cortical bone could be identified in all cases. All lesions were bordered by a hypointense rim (100%) and frequently showed a lobulated configuration (75%). Edema of medullary bone or soft tissues was not observed in any of the cases. Signal intensity of cartilaginous tumor tissue was typically hypo-or isointense relative to muscle on T1-weighted (100%) and hyperintense relative to fat on T2-weighted (92%) and T2*-weighted (100%) MR images. Radiographically significant calcifications of the tumor matrix, present in half of the cases, caused focal signal loss on MR images of all pulse sequences. Contrast enhancement was observed predominantly at the periphery of the lesions (100%), which on pathologic examinations typically contained fibrovascular bundles, surrounding the cartilage lobules. CONCLUSION: Periosteal chondroma appears to have a relatively typical MR appearance, which reflects the histologic composition of the lesion. In addition to radiography, MRI therefore can substantially aid in the preoperative diagnosis of this rare bone lesion.     

MRI of hemangioblastoma in the conus medullaris.

Hemangioblastoma of the conus medullaris with MRI has not been reported before. A 75-year-old man had a history of falling due to weakness of his left lower limb. MRI revealed a well-defined oval mass in the conus medullaris. The tumor had an isointense signal relative to spinal cord on T1-weighted images, hyperintense signal areas intermixed with punctate spots of hypointensity on T2-weighted images, and heterogeneous obvious enhancement on gadolinium-enhanced T1-weighted images. Associated abnormally tortuous vessels were noted in the dura proximal to the tumor. Histological findings were compatible with the diagnosis of hemangioblastoma. Hemangioblastoma should be included in the differential diagnosis in patients with an enhancing tumor and adjacent engorged vessels of the spinal cord.     

Tolosa-Hunt综合征的影像学表现(附12例报告)

目的 探讨Tolosa-Hunt综合征(THS)的影像学表现，为其临床诊断提供客观依据。方法 对1994-2002年临床确诊的12例THS进行了回顾性研究，分析其CT、MR平扫及增强扫描、DSA、磁共振血管成像(MRA)的表现。结果 12例中7例影像学表现异常，主要表现为一侧海绵窦增大，眶尖软组织肿块。CT呈软组织密度，MR T1WI呈等信号或稍低信号，T2WI呈稍高、稍低信号或等信号；强化扫描CT、MRI均示病变明显强化，同时伴有邻近硬膜强化。DSA检查2例示病侧颈内动脉海绵窦段稍狭窄，MRA检查1例示一侧颈内动脉海绵窦段狭窄，形态不规则。另5例无明显异常表现。结论 THS部分病例有影像学的异常改变，CT、MRI表现对其确诊有重要价值。     

Surface-coil MR of orbital pseudotumor

Fifteen patients with clinical presentations compatible with idiopathic inflammatory orbital pseudotumor were examined by CT and MR imaging to determine if MR could add specificity to the CT appearance of this entity. MR was performed on a 1.5 T system, using surface-coil and head-coil techniques. Idiopathic pseudotumor was confirmed in nine patients on the basis of response to steroid therapy in the absence of local cause or systemic illness. One other patient had biopsy-proven idiopathic pseudotumor. Five patients proved to have other orbital entities, including metastases, infectious myositis, hemorrhage, and orbital sarcoid. In all 10 patients with confirmed pseudotumor, CT and MR were abnormal. MR abnormalities in 10 of 10 patients with pseudotumor were hypointense to fat and isointense to muscle on T1-weighted images. On T2-weighted images the lesions of pseudotumor were isointense or only minimally hyperintense to fat in nine of 10 cases; in one case, the enlarged muscle was markedly hyperintense to fat. The MR signal intensity of pseudotumor was similar to that found in infectious myositis and sarcoid. These findings contrasted to the MR appearance of the other disease entities examined. Metastases appeared markedly hyperintense to fat on T2-weighted images, while hematoma was hyperintense to muscle and isointense to fat on T1-weighted images and markedly hyperintense to fat on T2-weighted images. In our preliminary series, surface-coil MR appears to add specificity to the CT appearance of orbital pseudotumor.     

原发性脑淋巴瘤的影像诊断

目的分析免疫功能正常患者原发性脑淋巴瘤影像诊断。方法回顾性分析5例免疫功能正常,经病理证实的原发性脑淋巴瘤CT、MR和PET所见。结果肿瘤可发生于幕上或幕下,可单发或多发。CT扫描多表现为等密度或稍高密度肿块,T     

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。