颅内黑色素瘤的CT和MRI表现

目的：探讨颅内黑色素瘤的CT和MRI特点。材料和方法：回顾性分析2000～2006年我院手术病理证实5例颅内黑色素瘤（原发性4例，转移性1例）的3例CT和4例MRI表现。结果：CT平扫表现为类圆形高密度影2例和低密度影1例，均明显增强。MRI平扫呈短T1短T2信号3例和长短T1短T2信号1例。结论：颅内黑色素瘤CT无特征性；MRI有一定特征，MRI是诊断黑色素瘤的首选影像学检查手段。     

中枢神经系统黑色素瘤的影像诊断

目的：分析中枢神经系统黑色素瘤的MRI影像特征。材料和方法：10例中枢神经系统黑色素瘤患者，其中男女各5例，年龄11－59岁。9例病灶位于颅内，其中3例有皮肤黑色素瘤切除史；1例位地颈髓。10例全部行MRI检查，其中4例增强MRI扫描，2例CT平扫。结果：9例MRI均表现为不均－短T1、短T2信号，并在T2WI可见低信号肿块影，另1例显示不均一长T1短T2信号。4例为不均一明显强化，其中1例沿软脑膜转换；2例CT平扫为血肿密度。结论：MRI显示黑色素瘤具有特征性，显示脑膜浸润的范围和程度优于CT。     

颅内黑色素瘤的CT及MRI诊断

目的探讨颅内黑色素瘤的CT和MRI特征及病理和流行病学特点以提高诊断准确率,为临床治疗提供更多的信息。资料与方法搜集本院2002年1月至2011年4月经手术病理证实的12例黑色素瘤患者资料(男8例,年龄33～58岁,平均46岁;女4例,年龄38～53岁,平均48岁)。5例行CT平扫,9例行MRI平扫及增强检查,其中2例同时行CT平扫及MRI平扫加增强检查。结果原发颅内5例,转移7例。典型的黑色素瘤CT上多呈类圆形高密度病灶,MRI上呈短T1、短T2信号改变,液体衰减反转恢复(FLAIR)序列上多呈等或稍低信号,增强后有轻到中度强化。不典型黑色素瘤影像学表现多样,与其黑色素的含量及瘤内出血、囊变等情况密切相关。结论颅内黑色素瘤的CT及MRI表现具有特征性,综合分析能提高影像诊断准确率。     

颅内黑色素瘤的CT和MRI表现

目的探讨颅内黑色素瘤的CT和MR影像特点。方法回顾性分析1993年以来收治的5例颅内黑色素瘤的CT和MR影像特点。结果原发性黑色素瘤2例，转移性黑色素瘤3例。全部病例均行CT检查，表现为类圆形高密度影4例、类圆形低密度影1例；4例行MR检查，呈短T2、短T2者3例，稍长T1、短T2者1例。结论MRI有助于颅内黑色素瘤的诊断，在一定程度上可以区分原发性和转移性黑色素瘤。     

膝关节自发性骨坏死的MRI诊断(附15例报告)

目的 探讨膝关节自发性骨坏死(SONK)的影像学表现.方法 收集经临床和影像学资料诊断的SONK患者15例.全部行膝关节MRI检查,其中5例行CT检查,3例行平片检查.结果 MRI全部显示软骨下病灶,14例位于股骨髁持重部位.其中显示软骨下"骨折裂隙"征者2例;表现为软骨下线状长T1短T2信号,周围伴骨髓水肿信号者3例;显示软骨下局灶性稍长T1长T2信号者10例.5例CT检查中,只有2例清晰显示病灶;3例平片检查中,仅1例显示病灶.结论 MRI显示SONK病灶较CT、平片敏感.结合临床表现及MRI特征可作出诊断.     

MRI、CT诊断脊椎转移瘤的比较分析

目的:探讨脊椎转移瘤的MRI及CT征象,以提高脊椎转移瘤的早期诊断率。方法:对138例脊椎转移瘤患者进行MRI与CT检查,比较脊椎转移瘤在MRI和CT上的表现。结果:138例脊椎转移瘤共发现399个椎体异常,237处椎管受累,190处椎旁软组织肿块,178处病理性骨折。MRI表现为T1加权低信号74%(294/399);T2加权表现为高信号62%(249/399);脂肪抑制T2加权表现为高信号86%(344/399)。CT检出273处病灶表现为不同形态的骨质破坏,溶骨型66%(179/273),成骨型24%(65/273),混合型10%(29/273)。结论:MRI的敏感性和特异性高于CT,MRI和CT联合应用可提高脊椎转移瘤诊断的敏感性和准确性。     

色素沉着绒毛结节性滑膜炎的影像学表现

目的:探讨色素沉着绒毛结节性滑膜炎(PVNS)的影像学表现,以提高对该病的影像学诊断水平及鉴别诊断的能力。方法:回顾性分析11例经病理证实的PVNS影像学资料并进行总结。11例均行X线检查,其中2例同时行关节空气造影检查;CT平扫7例;10例行MRI检查,其中1例加增强扫描。结果:11例均为单关节发病,其中膝关节8例、踝关节2例、髋关节1例。主要影像学表现为:①关节囊肿胀及结节状软组织肿块:11例均显示关节囊肿胀,4例X线平片(36.3%)、5例CT(71.4%)及10例MRI(100%)显示结节状软组织肿块;②软骨下边缘清楚的骨侵蚀伴硬化缘6例:其中X线显示2例、CT显示6例、MRI显示5例;③滑膜增厚10例:4例CT(57.1%)、10例MRI(100%)显示滑膜增厚;其中弥漫性增厚8例,单纯局限性增厚2例;④关节腔积液及关节间隙的改变:关节腔积液9例(81.8%),关节间隙狭窄4例(36.3%);⑤多发结节的MRI信号改变:结节均呈长T1短T2信号者5例;信号混杂者3例;另2例既有长T1长T2信号,也有长T1短T2信号。结论:PVNS的影像学表现具有一定的特征,影像学检查(特别是MRI检查)大多能够做出正确诊断。     

原发性肛管直肠恶性黑色素瘤的CT和MRI表现

目的：探讨原发性肛管一直肠恶性黑色素瘤（AMM）的CT和MRI表现。方法：回顾性分析本院经病理证实的15例AMM患者的临床、CT、MRI和病理资料。11例行CT检查,3例行MRI检查,1例行CT和MRI检查。结果：15例AMM中,10例病变位于直肠远端与肛管交界处,2例位于直肠,3例位于肛管。肿瘤形态呈蕈伞形肿块9例,肠壁环形增厚4例,肠壁未见明显增厚2例。4例有肺部或者肝脏转移,5例有周围淋巴结转移。15例患者均未见明星的肠梗阻征象。CT平扫示肿块呈稍低密度,最大径约2～4cm,增强后强化方式不一,以中度强化为主。MRI示肿瘤在T2wI上以等信号为主,T2wI上以稍高信号为主,DWI上呈高信号,增强后均有明显强化。结论：AMM的CT和MRI表现具有一定特征性;但AMM病灶较大时,MRI信号不具有黑色素瘤特异性的典型信号。CT检查有助于发现远处转移灶,MRI检查对其鉴别诊断有提示价值。     

颅内表皮样囊肿的非典型CT和MRI表现

目的 探讨颅内表皮样囊肿的非典型CT和MRI表现,提高对本病的认识.方法 收集经手术病理证实的8例表皮样囊肿,术前均行MRI平扫,其中2例行扩散加权成像(difussion weighted imaging,DWI)检查,CT检查5例.MRI增强扫描4例.结果 8例表皮样囊肿发生于桥小脑角2例,大脑纵裂2例,脑实质2例,颅骨2例.CT显示囊肿表现为均匀高密度2例;混杂密度1例;囊壁及囊内钙化2例.MRI平扫2例T1WI呈均匀高信号,T2WI呈稍高、高信号;3例T1WI和T2WI呈混杂信号;3例T1WI呈不均匀低信号,T2WI呈高信号;其中1例DWI表现为高信号.4例MRI增强扫描显示囊壁显著环形强化和囊内不均匀强化2例,囊壁轻度强化2例.结论 颅内表皮样囊肿的CT和MRI非典型表现主要包括CT呈高密度、混杂密度、囊壁和囊内钙化,MRI T1 WI、T2WI呈高信号、混杂信号,增强扫描显著环形强化,在诊断时应充分结合DWI检查,以提高术前诊断准确性.     

脑静脉窦血栓形成的MRI诊断价值

目的:评价MRI对脑静脉窦血栓形成的诊断价值.方法:14例脑静脉窦血栓患者均行MRI平扫,其中9例行MRV或MRA检查,6例增强.7例患者同时接受CT检查.结果:①常规MRI检查表现为静脉窦流空信号消失(n=13/14),急性期(n=2/14) T1WI呈等信号,T2WI呈低信号;亚急性期(n=7/14)T1WI、T2WI均呈高信号;慢性期(n=4/14)T1WI、T2WI信号减低,表现复杂.增强扫描可见充盈缺损(n=6/6)及脑回样强化(n=1/6);②MRV(n=9/9)表现为受累静脉窦血流信号减弱或消失;③MRA检查(n=1/1)受累静脉窦异常显影;④7例同时行CT和MRI检查的患者共22个静脉窦受累,CT检出率45.4%,MRI检出率100%.结论:常规MRI联合MRV对诊断脑静脉窦血栓形成具有高度敏感性,是诊断脑静脉窦血栓形成的首选检查方法.     

成人眼球内葡萄膜黑色素瘤与非黑色素瘤MRI比较研究

目的比较分析成人眼球内葡萄膜黑色素瘤与非黑色素瘤性肿块的MRI征象,寻找最佳联合诊断特征。方法回顾性分析首都医科大学附属北京同仁医院2005年3月至2015年12月经手术病理或临床随访确诊的254例成人眼球内肿块患者的MRI资料,包括128例葡萄膜黑色素瘤和126例非黑色素瘤性肿块。采用χ2检验或独立样本t检验比较两组肿块的MRI征象,包括部位、形态、边缘、T1WI和T2WI信号(分别与脑灰质和玻璃体相比)特征及均匀度、高度、基底径、基底径与高度比值、强化程度、强化方式、有无伴发视网膜脱离;采用二元logistic回归分析获取具有鉴别诊断价值的MRI征象,并采用受试者操作特征(ROC)曲线分析其诊断黑色素瘤的灵敏度、特异度和准确率,建立logistic回归模型构建联合参数,评价其诊断效能。结果黑色素瘤与非黑色素瘤间肿块部位、形态、边缘、T1WI和T2WI信号(分别与脑灰质和玻璃体相比)、信号均匀度、强化程度、伴发视网膜脱离,肿瘤高度、基底径与高度比值差异有统计学意义(P<0.05)。二元logistic回归分析结果显示,肿块的T1WI和T2WI信号(与脑灰质相比)、高度、形态、部位、强化程度及伴发视网膜脱离是诊断黑色素瘤的有效指标,其中肿块的T2WI信号(与脑灰质相比)优势比(12.237)最大,准确率为86.2%。与脑灰质相比T2WI呈低信号和T1WI呈高信号的诊断准确率高于与玻璃体相比(Delong检验,P<0.001)。肿块的高度、强化程度、T1WI和T2WI信号(与脑灰质相比)联合诊断黑色素瘤的灵敏度、特异度和准确率分别为90.6%、92.1%和96.1%,高于任何单一指标(P<0.001)。结论综合分析肿块的T1WI和T2WI信号(与脑灰质相比)、高度、形态、部位、强化程度和伴发视网膜脱离情况可提高鉴别诊断葡萄膜黑色素瘤和非黑色素瘤性肿块的准确率,以脑灰质为参照物评估肿块的T1WI和T2WI信号优于玻璃体。     

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.     

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.     

Malignant uveal melanoma and similar lesions studied by computed tomography

Forty-four patients with intraocular disease were studied by computed tomography (CT); in 19 cases malignant uveal melanoma was considered the likely diagnosis. CT proved to be accurate in determining the location and size of uveal melanomas, demonstrating scleral invasion, and differentiating melanoma from choroidal detachment or angioma, toxocariasis, and senile macular degeneration. Astrocytic retinal hamartoma and medulloepithelioma could not be distinguished from melanoma with CT. On CT, uveal melanomas appeared as hyperdense lesions with slight to moderate contrast enhancement. Tumors thinner than 2 mm could not be seen. Using dynamic CT, we noted moderate peak amplitude, normal or delayed tissue transit time, and persistently elevated washout phase (downslope), indicating increased permeability as the result of an impaired tumor blood barrier. Histological types of uveal melanoma could not be differentiated on the basis of circulatory patterns. Dynamic CT may be useful in distinguishing uveal melanoma from choroidal hemangioma or hematoma.     

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。     

眼球肿瘤的CT和MRI表现及其临床价值

目的：探讨眼球肿瘤的CT和MRI表现及其在诊断和鉴别诊断中的价值。资料与方法：73例眼球肿瘤行CT扫描，45例行MRI扫描，回顾性分析眼球肿瘤的CT和MRI表现。结果：28例视网膜母细胞瘤CT表现为有钙化的肿块；26例色素膜黑色素瘤MRI显示为短T1短T2信号，增强后轻至中度强化；9例脉络膜骨瘤CT表现为眼球壁高密度扁平性肿块；6例转移瘤MRI表现为扁平性肿块，呈略长T1长T2信号；4例脉络膜血管瘤呈长T1明显长T2信号，增强后明显均匀强化。结论：CT和MRI可显示眼球肿瘤的形态、大小及内部特征，有助于诊断和鉴别诊断。     

MRI for the evaluation of scleral invasion and extrascleral extension of uveal melanomas

AIM: To study the diagnostic value of MRI for the detection of scleral infiltration and extrascleral extension of uveal melanoma. MATERIALS AND METHODS: Twelve consecutive patients with clinically suspected large uveal melanoma were examined by MRI. All of the patients underwent enucleation or exenteration. The clinical and histopathological findings were compared. RESULTS: The clinical diagnosis of uveal malignant melanoma was confirmed by histology in each case. MRI allowed detection of scleral infiltration with a sensitivity of 100% and a specificity of 50%. For extrascleral extension, MRI had a sensitivity of 100% and specificity of 89%. CONCLUSIONS: Using fat suppression technique and enhancement with contrast medium, MRI proved to be a valuable ancillary method for the assessment of scleral infiltration and extrascleral extension.     

鼻窦真菌球的 CT 及磁共振成像表现

目的：探讨鼻窦真菌球的CT、磁共振成像（MRI）特征性表现及诊断价值。方法回顾性分析35例经手术、组织病理学证实的鼻窦真菌球的影像学资料,35例患者均做CT平扫,其中4例做MRI平扫加增强扫描。结果鼻窦真菌球的主要CT表现为：①病变为单侧性（100%）;②病变部位以上颌窦为主（80%）,部分突入同侧鼻腔;其次为蝶窦（14%）;③病变窦腔内不均匀软组织密度影充填,其内可见呈斑点状、云絮状或条带状高密度钙化影（89%）;④局限性骨质增生（74%）及破坏（9%）。 MRI表现为：病变中心T1WI呈等信号,T2WI呈低信号,周围增厚黏膜T1WI呈低信号,T2WI呈高信号,增强扫描病变中心不强化,周围增厚黏膜明显强化。结论病变内钙化影是本病特征性的CT征象,是诊断该病较为可靠的依据,CT检查是诊断本病的重要手段;MRI能显示病变内真菌球的范围,有助于诊断。