颅内表皮样囊肿的MRI诊断

目的 分析颅内表皮样囊肿的MR影像特征。资料与方法经手术病理证实的颅内表皮祥囊肿30例,男13例,女17例,除9例仅作MR平扫外,其余均作MR平扫 增强扫描。12例选用FLAIR序列。结果 典型表现者27例,占90％,T1WI上表现为低信号,有时不均匀;非典型表现者3例,占10％,T1WI上肿瘤实质内为高信号。21例增强扫描中,16例无强化,1例分隔状强化,4例边缘强化。T2WI上大多表现为均匀高信号,少数信号不均匀。结论 典型常见的表皮样囊肿T1WI为低信号,信号欠均匀;非典型的表皮样囊肿T1WI呈高信号,信号形成原因是高浓度蛋白质所致,并非脂类物质。     

颅内表皮样囊肿的MRI表现

目的 研究颅内表皮样囊肿的ＭＲ影像特征。方法 经手术病理证实的表皮样囊肿患者３２例,男９例,女２３例,全部行ＭＲ检查,结果 典型表现者２９例,占９１％;Ｔ１ＷＩ上表现为低信号,有时不均匀。非典型表现者３例,占９％;Ｔ１ＷＩ上肿瘤实质内为短Ｔ１高信号。２０例增强扫描中,８例无强化,１１边缘强化,１例肿瘤周边和肿瘤内部吾条索样分隔物增强。Ｔ２ＷＩ上,１７例肿瘤信号等于脑脊液信号,１例明显高于脑脊液信号     

颅内表皮样囊肿的MRI表现

目的　分析颅内表皮样囊肿的MRI影像学表现。方法　证实的 18例患者中 ,男 7例 ,女 11例 ,全部行MRI检查。结果　典型表现者 16例 ,占 88.9% ,T1WI表现为低信号 ,T2 WI表现为高信号 ;不典型表现者 2例 ,占 11.1% ,T1WI表现为欠均匀高信号 ,T2 WI表现为高信号。增强扫描 ,16例肿瘤不强化 ,2例边缘强化。结论　典型表皮样囊肿是T1WI呈低信号 ,且欠均质 ;非典型表皮样囊肿T1WI呈高信号 ,应注意此类肿瘤的鉴别诊断。     

磁共振扩散成像诊断颅内表皮样囊肿

目的讨论磁共振扩散成像诊断颅内表皮样囊肿的有用性和特异性。方法分析15例经手术证实的颅内表皮样囊肿磁共振扩散成像的表现，也比较其他MRI序列，包括T1、T2WI、质子密度加权像和快速水抑制反转恢复(fast fluid attenuated inversion recovery FLAIR)序列。结果磁共振扩散成像显示所有肿瘤(15个瘤灶)呈明亮的高信号，肿瘤与周围脑组织和脑脊液形成鲜明的对比；对手术后小的残存肿瘤(4个瘤灶)和复发肿瘤(3个瘤灶)的检出也极其敏感。结论磁共振扩散成像对表皮样囊肿有高度的敏感性和特异性，对手术前的定性诊断和手术后肿瘤的残存以及肿瘤复发的判断起着重要的作用。     

颅内表皮样囊肿14例MRI分析

颅内表皮样囊肿叉称胆脂瘤或珍珠瘤,是一种较少见的先天性良性肿瘤。2001年6月～2005年3月,我院收治该病14例。现将其MRI表现分析如下。     

睾丸表皮样囊肿的MRI诊断价值

目的探究睾丸表皮样囊肿(TEC)的MRI表现,以提高对该病的认识。方法选取10例经病理证实的睾丸表皮样囊肿患者的MRI及临床病理资料。结果6例位于左侧睾丸,4例位于右侧睾丸;9例为类圆形,1例为椭圆形;9例病变边界均清晰,1例病灶边界局部欠清晰。T₁WI表现4例呈等/低混杂信号,4例呈均匀低信号,2例呈混杂高信号;T₂WI表现为5例呈不均匀高信号,1例呈均匀高信号,4例呈不均匀低信号;10例患者均行DWI检查,其中5例呈均匀高信号,3例呈不均匀高信号,2例呈不均匀低信号,平均ADC值约0.83×10^-3mm²/s;8例增强扫描均未见明显强化;2例瘤内合并出血,4例T₁WI可见“靶征”,10例T₂WI可见“低信号环征”,2例病变内在T₂WI呈不规则分层的“洋葱皮征”。结论TEC的MRI表现具有一定的特征性,T₁WI的“靶征”、T₂WI的“低信号环征”结合增强扫描图像有助于术前的准确诊断。     

CT和MRI对颅内表皮样囊肿诊断价值的评价

目的：评估CT和MRI对颅内表皮样囊肿的诊断价值，分析误诊原因，提高诊断水平。方法：44例经手术和病理证实的颅内表皮样囊肿，术前全部行常规MRI检查，其中19例行Gd-DTPA增强MRI检查；17例作CT平扫，其中12例作静脉注射增强CT检查。结果：颅内表皮样囊肿多位于桥小脑角池，本组病例中占34．9％(15／4例)；肿瘤多呈不规则形态，占70．45％(31／44例)；CT平扫多呈均匀低密度，占70．59％(12/17例)，造影后多无强化，占91．71％(11／12例)；MRT1加权像上多呈均匀低信号，但略高于脑脊液，T2加权像上多呈均匀高信号，占61．36％(27／44例)，Gd-DTPA增强后多无强化，占84．21％(16／19例)。肿瘤周围的脑组织均无水肿，占100％，肿瘤较大时可以挤压、推移周围脑组织或脑室结构，引起比较明显的占位效应，占70．45％(31／44例)；肿瘤较大时，很少引起阻塞性脑积水。结论：颅内表皮样囊肿在CT和MRI像上有特征性表现，MRI无论在定位和定性诊断上优于CT，Gd-DTPA的应用有助于颅内囊性占位的诊断与鉴别诊断。     

颅内巨大非典型表皮样囊肿1例

患者　男 ,2 8岁。头部外伤后头痛、头晕 12天 ,以往有癫痫病史 10余年。查体 :颅神经检查未见异常 ,右上肢浅感觉减退 ,四肢肌力正常 ,双侧膝腱反射亢进。实验室检查 :未见异常。MRI扫描 :左侧额、顶、颞部颅板下方见一 11.5cm×5 .0cm× 9.0cm大小梭形异常信号 ,与脑实质比较呈等T1长T2 信号 ,T2 WI高于脑脊液信号 ,其内信号均匀 ,相应部位的脑组织及脑室明显受压右移。左侧额骨增厚 ,尤以板障明显 ,最厚处达 1.5cm。MRI诊断 :皮样囊肿或表皮样囊肿。手术所见 :颅骨与脑组织之间见囊性肿物 ,囊内为黄色液体并掺杂部分固态物。镜检 :…     

颅内表皮样囊肿的CT、MRI诊断

目的　分析颅内表皮样囊肿的CT、MRI表现。方法　对 18例经手术、病理证实的颅内表皮样囊肿的CT、MRI表现作了回顾性分析。 18例表皮样囊肿均作了MRI平扫和增强扫描 ,其中 12例还作了CT平扫检查。对肿瘤发生部位、大小、形态、CT密度、MRI增强前后的信号强度以及邻近结构的改变作了观察。结果　肿瘤位于桥小脑角区 10例 ,鞍上或鞍旁 3例 ,松果体区和第四脑室内各 2例 ,小脑延髓池 1例。肿瘤大小不等 ,形态多呈不规则形 ,轮廓光整或呈分叶状。CT平扫 10例呈均匀低密度 ,2例呈稍不均匀的低密度 ,CT值在 -15～ 10HU之间。在MRT1WI图像上肿瘤呈不均匀的低信号 ,在T2 WI、FLAIR图像上均呈不均匀的高信号。增强后除 1例肿瘤边缘似有轻微强化外 ,其余肿瘤均无明显的强化。结论　典型的颅内表皮样囊肿的CT、MRI表现较具特征性 ,通过CT、MRI检查可以作出准确诊断 ,并能与其他类似的颅内病变鉴别     

脑内型表皮样囊肿的MRI诊断

目的探讨脑内型表皮样囊肿的MRI特点,以加强对该病的认识,提高正确诊断率。资料与方法分析经手术病理证实的8例脑内型表皮样囊肿的MRI表现。全部患者均进行了T1WI、T2WI平扫及增强检查,5例患者行液体衰减反转恢复（FLAIR）序列检查。结果8例表皮样囊肿中,位于颞叶5例,额叶2例,额、颞叶交界区1例。所有病灶均发生在皮质区或皮质下区。病变轮廓不光整者5例,较光整者3例。病变与周围组织结构均分界清晰。在T1WI上病灶呈均匀低信号3例,以低信号为主其内间以斑片状、点状及条状中等信号或略高信号者4例,中心呈低、等混杂信号外围见同心圆形等信号者1例;在T2WI上呈均匀高信号,信号强度与脑脊液信号相似者4例,以高信号为主其内间以斑片状、点状及条状略高信号者3例,以高信号为主其内间以略高信号及略低信号者1例;5例行FLAIR序列检查,病灶均呈略高、等、低混杂信号,病灶周边环以线样或斑片样高信号。除1例病灶周围脑组织有轻度水肿外,均未见灶周水肿征象。病灶占位效应轻,周围组织受压征象不明显。MR增强扫描,2例见斑片状不均匀强化,其余病例均未见明显强化。结论脑内型表皮样囊肿的MRI表现具特征性,MRI表现有助于对该病的诊断。     

弥散加权成像与MRI增强诊断表皮样囊肿的比较研究

目的:比较弥散加权成像(DWI)与MRI增强(CE-MRI)对表皮样囊肿的检出敏感性,评价DWI的临床应用价值.方法:对59例初次检查及66例术后复查疑似表皮样囊肿的患者行回顾性研究,所有病例均行常规序列[T1 WI、Tz WI、液体衰减反转恢复序列(FLAIR)]、弥散加权成像(DWI)和钆对比剂增强扫描(CE-MRI)检查.将所有图像分为DWI结合常规序列(Ⅰ组)、CE-MR1结合常规序列(Ⅱ组)及DWI联合CE-MRI并结合常规序列(Ⅲ组)三组进行判断,诊断结果与手术病理进行比较,判定三组检查方法的敏感性,组间比较采用配对资料的x2检验.另外选择32例经病理及随访观察证实的蛛网膜囊肿做对照,分析信号特征并测量ADC值,与表皮样囊肿ADC值的比较采用配对t检验.结果:Ⅰ组、Ⅱ组诊断表皮样囊肿的敏感性分别为90.5％、57.8％,二者具有明显统计学差异(x2=25.714,P＜0.01).Ⅲ组诊断表皮样囊肿的敏感性为91.8％,与11组具有明显统计学差异(x2=30.250,P＜0.01),与Ⅰ组没有统计学差异(x2=0.250,P＞0.05).病理证实的88例表皮样囊肿DWI均呈明显高信号,32例蛛网膜囊肿DW1均呈明显低信号,表皮样囊肿的ADC值(1.06士0.21×103)mm2/s明显低于蛛网膜囊肿的的ADC值(3.24±0.39×101)mm2/s,两者比较差异有统计学意义(t =-3.647,P＜0.01).结论:DWI较MRI增强检查对表皮样囊肿具有较高的检出率,在与蛛网膜囊肿的鉴别及判断表皮样囊肿复发上能提供有价值的诊断信息.     

Epidermoid cyst of the conus medullaris: atypical MRI and angiographic features

We report a 50-year-old man with an epidermoid cyst of the conus medullaris which showed a nodular gadolinium enhancement on MRI and a blush on angiography. These radiological features are compared with pathological examination.     

Three-dimensional chemical shift-selective MRI of a ruptured intracranial dermoid cyst

We report a man with a ruptured intracranial dermoid cyst, suffering from headache, nausea, vomiting and a generalised seizure. MRI was performed before and 2 weeks after surgical resection. On T1-weighted images the tumour gave high signal, as did fatty material in the frontal and parietal brain sulci. Identification of this hyperintense material as lipids was possible by chemical-shift-selective 3 D gradient-echo imaging, which provided excellent contrast between the subarachnoid lipids and the adjacent normal brain, with a good spatial resolution. Possible complications of subarachnoid and intraventricular lipid particles after dermoid cyst rupture are discussed and the diagnostic value of 3 D chemical-shift-selective additional to conventional T1-weighted spin-echo images in identification of even small amounts of fat is emphasised.     

Intraspinal epidermoid cyst: diffusion-weighted MRI

We report a 7-year-old boy who presented with two-month history of worsening low back and right leg pain. Conventional MR images demonstrated a poorly outlined intradural mass recognized by the displacement of the conus medullaris and the nerve roots of the cauda equina at the L2–3 level. The signal intensity of the lesion was similar to CSF. There was no contrast enhancement of the lesion. Diffusion-weighted images and ADC values revealed restricted diffusion within the mass. Myelography confirmed the mass as an intradural filling defect with myelographic block at the L2–3 level. The patient underwent total surgical excision of the mass. Pathologic examination revealed the diagnosis of epidermoid cyst. Received: 11 July 2000 Accepted: 1 December 2000     

Intradiploic epidermoid cyst with focal internal enhancement

We report a case of intradiploic epidermoid cyst with focal internal enhancement. The patient was a 55-year-old woman presenting with right temporal head protrusion and head heaviness. Skull radiography and computed tomography demonstrated an expansile mass in the right diploic space. On magnetic resonance imaging, the mass showed makedly high signal T2-weighted images (T2WI) and intermediate to low signal on T1WI. On contrast-enhanced T1WI, there was nodular internal enhancement, which corresponded to neovascularity on pathology, as well as rim-like enhancement. It should be noted that internal enhancement, an indicator of malignant transformation, may be seen even in a benign epidermoid cyst.     

Duplication of a vertebral artery associated with epidermoid cyst of the posterior fossa

A case of a duplication of the left vertebral artery associated with a premedullary epidermoid cyst at the level of the foramen magnum is described. The close proximity of the two malformative lesions in the present case and the overlap of the periods when such developmental abnormalities can arise suggest that they might be causally linked. Received 31 January 1996; Revision received 18 March 1996; Accepted 6 June 1996     

颅内不典型表皮样囊肿MR表现和病理对照分析

目的 探讨颅内不典型表皮样囊肿的MR表现及其与病理所见的关系.方法 回顾性分析7例颅内不典型表皮样囊肿的MR表现,并与手术病理所见对照.全部病例均行MR平扫检查,2例行MR增强扫描,1例行CT扫描.结果 4例表皮样囊肿位于小脑半球实质,2例位于大脑半球实质,1例位于小脑周围.T1WI 6例表皮样囊肿呈高信号,1例呈等信号,T2WI 5例呈很低信号,2例呈高信号.增强扫描囊肿不强化.病理检查镜下可见囊肿内大量蛋白物质.结论 颅内表皮样囊肿呈短T1和等T1信号主要与囊肿内存在大量蛋白物质有关,需要与颅内短T1信号的病变鉴别.     

体部表皮样囊肿的 CT 和 MRI 表现

目的：探讨体部表皮样囊肿的 CT 和 MRI 影像特征。方法回顾性分析经手术病理证实的78例患者共81个病灶的临床、影像及病理资料,其中75例行 CT 扫描,17例行 MRI 检查。结果75例单发,3例多发。病灶主要发生于头面部(26/78)和躯干部(37/78),其次为四肢(14/78),盆部(3/78)和腹膜后(1/78)者较少。53例56个病灶(69.1%)CT 图像表现为类圆形或椭圆形囊性低密度肿块,囊壁菲薄,无强化,MRI 图像上 T1 WI 呈低信号或等低信号、T2 WI 呈高信号影,DWI 呈高信号。25例(30.9%) CT 表现不典型,其中囊壁增厚并强化者15例,呈片状软组织密度影者5例,呈高密度结节者3例,呈完全钙化者2例。结论典型体部表皮样囊肿影像表现具有明显特征性,CT 及 MRI 能够反映病灶炎症、感染、钙化等病理变化,有助于加深对体部表皮样囊肿少见征象的认识。     

磁共振扩散加权成像对于颅内表皮样囊肿的诊断价值

目的:探讨磁共振扩散加权成像(DWI)对于颅内表皮样囊肿的诊断价值。方法:回顾性分析11例经手术病理证实的颅内表皮样囊肿术前常规MRI和DWI的信号特征。结果:11例均为单发;7例表现为囊状均匀性长T1长T2信号,4例病灶信号不均匀,以长T1长T2信号为主,其内混杂少许等T1等T2信号;5例行增强扫描均未见异常强化;所有病灶在DWI上均表现为明显高信号,边界清楚,ADC图表现为中等信号。结论:DWI对于颅内表皮样囊肿的诊断及鉴别诊断具有重要价值,应作为首选检查与常规扫描同时应用。