眼球脉络膜黑色素瘤的CT和MRI表现

目的:分析眼球脉络膜黑色素瘤的CT和MRI表现,并探讨其在诊断和鉴别诊断中的价值.材料和方法:回顾性分析经手术和病理证实的25例眼球脉络膜黑色素瘤,其中CT扫描13例,MRI检查7例,CT加MRI检查5例.结果:本组仅1例肿瘤侵及球外,其余均局限于眼球内.3例为梭形,21例为蘑菇形.CT平扫密度较均匀,接近眼环密度;增强后12例呈明显均匀强化,3例不均匀强化.1例伴有斑片状钙化.14例显示肿瘤的一侧或两侧周边区半月形视网膜剥离.与玻璃体比较T1WI呈高信号,T2WI呈低信号.10例显示视网膜剥离,渗液在T1WI、T2WI上均呈中高信号.增强后T1WI示瘤体中等至明显强化,周边积液未见强化,仅1例周边积液显示中等强化.结论:CT与MRI均能显示眼球内的病灶,MRI对该病的诊断及鉴别诊断优于CT且具有特征性.     

眼球脉络膜血管瘤的影像学表现

目的：探讨眼球脉络膜血管瘤的CT、MRI表现及其诊断、鉴别诊断价值。方法：回顾性分析9例经病理（3例）和临床证实（6例）的脉络膜血管瘤。CT扫描6例，MR检查4例，9例均行B超检查，3例作了眼底荧光血管造影。结果：2例CT平扫示眼球后极球壁轻度或新月形增厚，与球壁呈等密度，5例（1例平扫＋增强）增强示眼球后极部高密度梭形或扁平状隆起均匀肿块，瘤体强化明显。与玻璃体比较3例MR T1WI呈高信号，T2WI呈低信号，与视神经、眼外肌相比呈等信号；1例较小肿瘤辅以增强T1WI脂肪抑制技术被清楚显示。渗出性视网膜脱离在T1WI、T2WI上均呈中、高信号；增强T1WI瘤体显著强化，边界清晰，且信号均匀。B超检查8例为实质不均质肿块占位，1例为均质肿块占位，9例均探及视网膜脱离光带。结论：CT＋MRI＋B超检查对脉络膜血管瘤可得到较为全面的影像学诊断资料，MRI在该病的诊断及鉴别诊断中较CT及B超更具敏感性和特异性。     

眼球孤立性脉络膜血管瘤的HR-MRI表现

目的　探讨眼球孤立性脉络膜血管瘤的高分辨率磁共振 (HR MRI)影像学特征 ,进一步提高诊断水平。资料与方法　回顾性分析诊断明确的孤立性脉络膜血管瘤 16例共计 17个病灶的位置、数目、形态、大小、MRI信号、强化情况、有无合并视网膜脱离及有无视神经和眼外侵犯等。所有病例均行HR MRI及增强扫描 ,部分病例行脂肪抑制。结果　 17个病灶中的 16个呈扁丘状位于眼球内壁的后极。 15个病灶厚度 <5mm ,平均厚度为2 .9mm。病灶边缘清晰 ,T1WI上呈轻度高信号者 16个 ,T2 WI上呈等信号者 15个 ,增强扫描显著强化者有 12个。 3例合并视网膜脱离 ,在T2 WI上多呈等信号 ,T1WI上呈轻度高信号者 ,均无强化。无视神经及眼外侵犯病例。结论　 94 %孤立性脉络膜血管瘤的HR MRI表现具有特征性 ,表现为位于眼球内壁后极的较小、基底较宽、边缘清晰的扁丘状病灶。其T1WI信号高于玻璃体 ,T2 WI信号等于玻璃体 ,增强扫描瘤体显著强化。明确其HR MRI影像学特征有助于临床与恶性葡萄膜黑色素瘤相鉴别 ,避免不必要的眼球摘除     

黑色素瘤脑转移的低场MRI表现

目的 总结黑色素瘤脑转移的低场MRI表现,以提高对该病的认识. 资料与方法 回顾分析8例经手术病理证实的黑色素瘤脑转移患者的MRI表现. 结果 黑色素瘤脑转移患者的MRI表现分为3种:(1)脑内多发大小不等、球状、结节状病灶,T1WI高信号,T2WI上为低信号,灶周水肿明显,增强扫描病灶呈均一高信号,共4例;(2)肿瘤内可有出血而致信号不均匀,增强后多呈不规则、花环状强化影,共3例;(3)在前两种表现基础上合并脑膜转移,共1例. 结论 黑色素瘤脑转移的瘤体易出血和富含黑色素颗粒这两个特征,决定其MRI表现的特性.     

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。     

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。     

视网膜脱离的MRI诊断价值

目的:探讨视网膜脱离的MRI表现及诊断价值。方法:回顾性分析经手术和临床证实的16例(17只眼)视网膜脱离患者的MRI图像特征。结果:部分性脱离11例(12只眼),完全性脱离5例;脱落部位以累及视乳头双侧者较多见(9/17),发生于单侧者多位于颞侧(6/8);脱落的形态多呈"v"字形(8/17)和月牙形(6/17),其次不规则弧形(3/17);病变信号强度T1WI以等或稍高信号为主(16/17),仅1例呈稍低信号,T2WI信号均高于玻璃体信号;合并玻璃体出血、混浊5例,脉络膜黑色素瘤1例,脉络膜脱离1例。结论:视网膜脱离的MRI表现较具特征性,MRI对视网膜脱离的诊断具有重要价值。     

MRI与4DCEMRA鉴别肢体脂肪性肿瘤良恶性的意义

目的:探讨MRI联合4DCEMRA鉴别肢体脂肪性肿瘤良恶性的意义。方法:对7例肢体脂肪肉瘤和7例肢体脂肪瘤的MRI、4DCEMRA资料进行回顾性分析;比较二者MRI、4DCEMRA的差异。结果:MRI信号:脂肪肉瘤T1WI信号复杂、不均匀,表现为低至高各种信号或混杂信号;T2WI呈不均匀稍高、高信号为主;FS-T2WI呈不均匀高信号,T1WI所示高信号呈等信号;病灶呈明显或中度不均匀强化,3例伴有厚分隔、2例伴有薄分隔。脂肪瘤T1WI、T2WI呈高信号,4例伴有薄分隔;FS-T2WI呈等信号;分隔中度强化,余未见强化。4DCEMRA表现:脂肪肉瘤可见异常动脉分支进入瘤体,供血动脉显示、瘤体可见染色;瘤周引流静脉增多、增粗。脂肪瘤未见肿瘤血管染色及供血动脉。结论:MRI联合4DCEMRA对鉴别肢体脂肪性肿瘤良恶性具有定性诊断价值。     

鼻道、鼻咽恶性黑色素瘤的MRI诊断

目的 分析鼻道、鼻咽恶性黑色素瘤的MRI表现,探讨其诊断要点.方法 回顾性分析经病理证实的8例鼻道、鼻咽恶性黑色素瘤的MRI特征及临床资料,所有患者均行MR平扫、增强及动态增强检查.结果 肿瘤位于中鼻道1例,鼻咽部2例,鼻腔、上颌窦及同侧筛窦5例.5例可见明显骨质破坏并侵犯邻近结构,累及翼腭窝3例、颞下窝2例、眼眶4例、前颅底2例、咽旁间隙1例.MRI表现:3例直径＜2 cm,呈类圆形肿块,T1WI为高信号,T2 WI为低信号,呈明显均匀强化.5例直径＞3 cm,不规则肿块,MRI表现为混杂信号,T1WI以等、低信号为主,其内有斑片状高信号;在T2WI,1例以等低、信号为主,4例以稍高信号为主,增强扫描呈轻度不均匀强化.动态增强扫描时间-信号强度曲线平台型、流出型各4例.结论 鼻道、鼻咽恶性黑色素瘤MRI信号特征与肿瘤大小相关.肿瘤较小时T1WI呈高信号,T2WI呈低信号;肿瘤较大时MRI信号混杂,轻度不均匀强化为其特征.     

Intraocular tumors: evaluation with MR imaging

Sixty-seven ocular tumors were studied with magnetic resonance (MR) imaging and computed tomography (CT). These tumors included primary uveal melanoma (n = 55), circumscribed choroidal hemangioma (n = 3), diffuse choroidal hemangioma (n = 1), retinal capillary hemangioma (n = 1), medulloepithelioma (n = 1), choroidal nevus (n = 1), retinoblastoma (n = 1), and choroidal metastases (n = 4). MR imaging demonstrated all these lesions, while CT demonstrated 88%. Associated retinal detachment was more easily distinguished from the neoplasms with MR imaging. Extrascleral extension of melanoma and hemorrhagic cystic necrosis within the melanoma were clearly demonstrated with MR imaging, but not with CT. Ninety-three percent of melanomas were markedly hyperintense, compared with the intensity of the vitreous body, on T1-weighted images and hypointense on T2-weighted images. All metastatic lesions were isointense on T1-weighted images and hypointense on T2-weighted images. The circumscribed choroidal hemangiomas were hyperintense on T1-weighted images and isointense on T2-weighted images. MR imaging is superior to CT in detection of intraocular tumors and may be more specific in diagnosis.     

Malignant uveal melanoma and simulating lesions: MR imaging evaluation

Twenty-one patients with intraocular disease were studied by magnetic resonance (MR) imaging and computed tomography (CT). In 13 cases, malignant uveal melanoma was considered the likely diagnosis. Both imaging methods were accurate in determining the location and size of uveal melanomas. MR imaging was superior for the assessment of possible associated retinal detachment, for assessment of vitreous change, and for differentiating uveal melanoma from choroidal hemangioma and choroidal detachment. A case of retinal gliosis could not be differentiated from uveal melanoma by either technique. Uveal melanomas appeared as hyperintense lesions on T1-weighted images and as hypointense lesions on T2-weighted images. High signal intensity of the vitreous was observed in patients with vitritis and in those who were thought to have protein leaking into the vitreous as a result of impairment of the retinal-blood barrier.     

Intraocular metastases: differential diagnosis from uveal melanomas with high-resolution MRI using a surface coil

Magnetic resonance imaging with dedicated surface coils plays a pivotal role in differential diagnosis and staging of intraocular tumors. The purpose of this study was to establish MRI criteria for the differential diagnosis of uveal melanomas and intraocular metastases. In a prospective study 44 eyes in 36 patients with intraocular metastases and 200 patients with uveal melanomas were investigated with MRI using a 1.5-T scanner and a 5-cm surface coil. Both quantitative and qualitative evaluation of the resulting images was performed. The MR signal intensities typically expected for metastases (slightly hyperintense on non-contrast T1-weighted images and hypointense on T2-weighted images compared to the vitreous body) were seen in only 23.1%. The typical melanoma signal of either moderate or strong hyperintensity on T1-weighted images and hypointensity on T2-weighted images was seen in 69.4% of the proven melanomas. Contrast enhancement was observed in both metastases and melanomas. Morphological differences between metastases and melanomas were detected in tumor size, shape, position, frequency of retinal detachment, and homogeneity of the tumor. Differentiation between intraocular metastases and uveal melanoma is limited by overlap of signal intensities. Some improvement is achieved with morphologic criteria.     

眼色素膜黑色素瘤的CT与MRI研究

目的研究色素膜黑色素瘤的ＣＴ和ＭＲＩ表现，探讨最佳ＭＲＩ的扫描序列。材料与方法１５例患者用各种ＭＲＩ序列进行扫描，其中１１例行ＣＴ扫描，并与手术病理进行对照。结果ＣＴ示９例表现为与眼外肌等密度的肿块，２例肿瘤太小未能显示。ＭＲＩ示１４例具有典型的短Ｔ１、短Ｔ２信号，１例３ｍｍ高度的虹膜黑色素瘤在Ｔ１ＷＩ上未能显示；１１例伴有视网膜脱离，呈短Ｔ１及长Ｔ２信号，与肿瘤在Ｔ１ＷＩ上很难区分。使用脂肪抑制和增强扫描的Ｔ１ＷＩ能较好地显示较小肿瘤（高度＜５ｍｍ）能区分肿瘤及其伴发的视网膜脱离。结论ＭＲＩ显示黑色素瘤的准确率和特异性较ＣＴ和Ｂ超优越。     

Shortcomings and pitfalls of ocular MRI

Summary MRI was performed in 41 patients with ocular lesions: 27 cases of malignant melanoma, 5 of haemorrhage, 3 of choroidal metastasis, 3 of senile disciform macular degeneration, 2 retinoblastomas and 1 hamartoma. On MRI 5 small lesions (<2 mm thick): 1 melanoma, the 3 metastases and the hamartoma, were not seen. All the malignant melanomas visualised were hyperintense compared to the vitreous on T1-weighted images. On T2-weighted images 24 of 26 lesions were hypointense compared to the vitreous. The remaining two lesions were almost isointense, corresponding to amelanotic lesions. These MRI features did not differ significantly from those of retinoblastomas, senile disciform macular degeneration or subacute choroidal haemorrhage. Major shortcomings of MRI in lesions of the globe lie in a lack of spatial resolution and poor specificity of the findings.     

Magnetic resonance imaging in lesions of the eye globe

Magnetic Resonance Imaging (MRI) findings in 22 patients with lesions of the globe were examined. There were 16 cases of malignant uveal melanoma, 2 cases of retinoblastoma, 3 cases of hemorrhagic choroidal detachment and 1 case of senile macula degeneration. MRI adequately depicted the lesions in 20 cases. In two cases MRI findings were unconclusive due to movement artifacts of the eye globe. Fourteen out of 16 uveal melanomas displayed typical T1 and T2 shortening. In the two other cases the hypointense aspect on T2-weighted images was less pronounced due to a lesser amount of melanin in the lesions as demonstrated by subsequent histology. Unlike with CT, the tumoral lesions could clearly be differentiated from subretinal exudate. The case of senile macula degeneration, two retinoblastomas and two cases of hemorrhagic choroidal detachment had the same MRI characteristics as melanomas.     

颅咽管瘤的MRI诊断

目的　评价MRI诊断颅咽管瘤的价值。方法　回顾性分析 5 2例颅咽管瘤的MRI表现 ,并与病理比较。结果　 37例( 71.2 % )的颅咽管瘤位于鞍上。颅咽管瘤囊液的MRI信号在T2 加权像上一般呈较均一的高信号 ,而在T1加权像上则呈低、等、高等多种表现 ,反映了囊液内不同病理成分的存在。结论　直接的多维成像能力及敏感的信号变化 ,使MRI成为诊断颅咽管瘤的有效方法     

Radiotherapy of choroidal metastases

With binocular indirect ophthalmoscopy, fluorescin angiography and ultrasonography 68 choroidal metastases in 52 eyes of 39 patients were diagnosed. The primary tumors were mainly breast cancer (81%) and lung cancer (10%). After radiation treatment the visual acuity improved in 17 eyes (38%), stabilized in 15 eyes (33%), whereas in 13 eyes (29%) deterioration could not be prevented (seven eyes unknown). Regression of the lesions or its accompanying secondary retinal detachment was seen in 78% of the eyes treated. Acute transient side effects of radiation therapy were kerato-conjunctivitis (nine patients) and acute glaucoma in one patient. No cataractous changes of the lens were observed in the post radiation period (one to 42 months). Irradiation of choroidal metastases can contribute to improvement of the quality of life with a treatment scheme of 30 Gy in ten daily fractions.