桥小脑角区肿瘤的MRI诊断和鉴别诊断

目的 :探讨桥小脑角区肿瘤MRI的表现及特征。材料和方法 :分析 193例资料完整 ,均经手术和病理证实的桥小脑角区肿瘤 ,其中听神经瘤 135例 ,三叉神经瘤为 30例 ,脑膜瘤 12例 ,胆脂瘤 4例 ,蛛网膜囊肿 2例 ,动脉瘤 1例 ,血管母细胞瘤 4例 ,脉络丛乳头状瘤 3例 ,海绵状血管瘤 1例 ,转移瘤 1例。结果 :桥小脑角区肿瘤中 ,脑外肿瘤 95 .3% ,脑内肿瘤 4.7% ;良性肿瘤占 98.4% ,恶性肿瘤占 1.6%。发生于桥小脑角区的前三位肿瘤分别为听神经瘤 69.9% ,三叉神经瘤 15 .5 % ,脑膜瘤 6.2 % ,该区肿瘤大部分有特征性MRI表现 ,术前定位、定性诊断准确率分别为 10 0 %、96.4%。结论 :MRI是检查桥小角区肿瘤的首选方法 ,对桥小脑角区肿瘤诊断和鉴别有重要价值     

桥小脑角区肿瘤的MRI诊断

目的：探讨桥小脑角区肿瘤MRI的表现及特征。材料和方法：分析297例资料完整、均经手术和病理证实的桥脑角区肿瘤。其中听神经瘤184例，三叉神经瘤39例，脑膜瘤27例，胆脂瘤13例，蛛网膜囊肿4例，动脉瘤1例，血管母细胞瘤6例，脉络丛乳头状瘤3例，海绵状血管瘤5例，转移瘤3例，脊索瘤3例。结果 桥小脑角区肿瘤中，脑外肿瘤93．8％，脑内肿瘤6．2％，发生于桥小脑角区的前三位肿瘤分别为听神经瘤63．6％，三叉神经瘤13．3％，脑膜瘤9．2％。该区肿瘤大部分具有特征性MRI表现。术前定位定性诊断准确率分别为100％、96．4％。结论：MRI是检查桥脑角区肿瘤的首选方法，对桥小脑角区肿瘤诊断和鉴别诊断有重要价值。     

桥小脑角区肿瘤的MRI诊断和鉴别诊断

目的：分析桥小脑角区肿瘤的MRI表现和特征，提高桥小脑角区肿瘤的MRI诊断准确率。材料和方法：收集临床资料完整、经手术和病理证实的桥小脑角区肿瘤36例，全部行MRI平扫及增强检查。结果：听神经瘤16例，三叉神经瘤7例，脑膜瘤6例，胆脂瘤4例，蛛网膜囊肿2例，血管母细胞瘤1例。桥小脑角区肿瘤大部分有其特征性表现。结论：MRI对桥小脑角区肿瘤的诊断和鉴别诊断具有重要价值。     

桥小脑角区肿瘤的磁共振成像诊断

目的：探讨桥小脑角区肿瘤的磁共振成像（MRI）的影像学表现及鉴别诊断,以提高其诊断水平。方法总结分析经影像学及手术病理证实的桥小脑角区肿瘤共33例。其中听神经瘤14例,三叉神经瘤8例,脑膜瘤2例,胆脂瘤3例,蛛网膜囊肿4例,恶性肉芽肿1例,颈静脉球瘤1例。所有患者均行MRI平扫及增强扫描,部分病例结合CT扫描。总结分析肿瘤的形态、大小、生长方式、信号特征及强化方式。结果桥小脑角区的肿瘤以听神经瘤占首位,其次为三叉神经瘤、胆脂瘤、蛛网膜囊肿、脑膜瘤。还有一些少见的肿瘤,诸如恶性肉芽肿、颈静脉球瘤等。结论桥小脑角区肿瘤MRI表现各具有不同特性,了解这些特征有助于诊断及鉴别诊断,为临床治疗及手术提供依据。     

桥小脑角肿瘤MRI三维薄层扫描的诊断价值

目的:探讨桥小脑角肿瘤MRI三维薄层扫描的诊断价值,提高诊断准确率。方法:应用三维薄层扫描序列,结合常规MRI序列,分析52例桥小脑角肿瘤MRI表现并与手术结果对照。结果:桥小脑角区肿瘤中,听神经瘤27例,脑膜瘤11例,三叉神经瘤4例,胆脂瘤4例,蛛网膜囊肿3例,海绵状血管瘤2例,转移瘤1例。位于左侧桥小脑角区占17%,位于右侧桥小脑角区占19%,平扫MRI对桥小脑角肿瘤的检出率、定位率、定性率分别为92%、92%、86%。三维薄层扫描对桥小脑角肿瘤的检出率、定位率、定性率分别为100%、100%、96%。结论:MRI三维薄层扫描与常规MRI比较,能清晰显示肿瘤性病变与周围神经及邻近血管之间的关系,明显提高了检出率和鉴别诊断的准确率,为临床确定治疗方案有极其重要的指导意义,因此三维薄层扫描在桥小脑角肿瘤诊断中的应用值得广泛推广。     

桥小脑角区占位病变的MRI诊断及鉴别诊断

目的:探讨桥小脑角区(CPA)占位病变MR诊断及鉴别诊断价值。方法:搜集收治经手术和病理证实的桥小脑角区肿瘤患者91例,回顾性分析其MR表现。结果:听神经瘤64例,脑膜瘤17例,三叉神经瘤5例,表皮样囊肿3例,颈静脉球瘤1例,血管母细胞瘤1例。结论:MRI能较好地对CPA区占位病变作出诊断及鉴别诊断。     

桥小脑角区肿瘤的MRI诊断

目的：分析桥小脑角区肿瘤的ＭＲＩ 表现,提高桥小脑角区肿瘤的ＭＲＩ 诊断准确率。材料和方法：搜集一组经手术及病理证实的桥小脑角区肿瘤４５ 例,全部行ＭＲＩ 平扫及增强检查。结果：本组４５ 例中听神经瘤１８ 例,脑膜瘤８ 例,三叉神经瘤６ 例,胆脂瘤３ 例,血管母细胞瘤４ 例,海绵状血管瘤４ 例,脊索瘤２ 例。肿瘤位于左侧桥小脑角区占６９ ％ ,位于右侧桥小脑角区占３１ ％ 。８７ ％ 的肿瘤呈园形或类园形,轮廓较清晰,占位效应明显,在Ｔ１ ＷＩ上多呈低等信号,Ｔ２ ＷＩ 上多呈高信号,增强后呈明显均匀强化。但各种肿瘤又有其特征性ＭＲ 改变,如三叉神经瘤跨中后颅窝生长,胆脂瘤沿脑池生长,听神经溜,三叉神经瘤,血管母细胞瘤多见囊变、坏死,海绵状血管瘤多见出血,脑膜瘤、脊索瘤有不规则钙化,多数脑膜瘤增强后见脑膜尾征。ＭＲＩ 对桥小脑角区肿瘤的检出率、定位率、定性率分别为１００ ％ 、１００ ％ 、９０ ％ 。结论：ＭＲＩ 对桥小脑角区肿瘤的诊断及鉴别诊断有重要价值。     

桥小脑角肿瘤CT与MRI鉴别诊断

目的：探讨桥小脑角肿瘤的CT与删影像学特征。方法：回顾性分析经手术与病理证实的24例桥小脑角区肿瘤，其中听神经瘤10例，脑膜瘤7例，三叉神经瘤4例，表皮样囊肿2例，蛛网膜囊肿1例。年龄16．74岁，平均年龄45岁。结果：各种桥小脑肿瘤均有其CT与MRI的特殊征象。结论：Cr与MRI在桥小脑角肿瘤的诊断中具有重要价值。     

MR增强检查在桥小脑角肿瘤的诊断价值

目的探讨MRI增强检查诊断桥小脑角肿瘤的价值.方法研究68例手术和病理证实的桥小脑角肿瘤的资料,其中听神经瘤34例,三叉神经瘤5例,脑膜瘤20例,胆脂瘤9例.所有病人均作了增强前后的MR扫描,包括轴位、矢状位和冠状位.结果34例听神经瘤中,23例增强呈结节-环状、多环状、花环状肿块,囊变率68%;11例呈均匀肿块;34例显示面听神经束增粗强化与肿瘤相连,其中呈"荸荠”征15例,为听神经瘤的典型征像.5例三叉神经瘤强化呈结节-环状、或多环状3例,哑铃状2例,5例患侧三叉神经均显示不清,同侧面听神经受压.20例脑膜瘤中度强化均匀肿块;"脑膜尾”征11例,同侧面听神经束鞘膜强化、不增粗5例.9例胆脂瘤长T2、长T1与脑脊液一致,T1低信号中有比脑脊液信号稍高的组织,无强化表现,病变沿蛛网膜下腔扩展,基底动脉包埋5例.结论MRI增强检查能显示听神经瘤、三叉神经瘤、脑膜瘤、胆脂瘤的特征表现,诊断桥小脑角肿瘤有独特的价值.     

CT在三叉神经痛和半侧面肌痉挛诊断中的应用价值

目的:探讨CT在诊断三叉神经痛与半侧面肌痉挛中的价值。方法:将772例经手术治疗的三叉神经痛(326例)与半侧面肌痉挛(446例)患者的术前CT资料与手术结果进行对照分析。结果:①CT表现:772例患者中,CT发现患侧桥小脑角胆脂瘤26例,听神经瘤14例,三叉神经瘤8例,脑膜瘤6例,患侧桥小脑角扩张增粗血管490例(63.47%),CT未见异常者228例(29.6%);②手术病理结果:胆脂瘤27例,听神经瘤14例,三叉神经瘤8例,脑膜瘤6例,三叉神经或面神经根部异常血管压迫者696例(90.15%),术中未见异常者21例。结论:CT在病因诊断方面很有帮助,它既可以发现桥小脑角占位病变,又能显示桥小脑角扩张增粗的血管,是术前有效的检查方法。     

35例四脑室区肿瘤的MRI分析

目的评价磁共振成像（MRI）对四脑室区肿瘤的诊断价值。方法经临床手术病理证实的四脑室区肿瘤35例，均接受常规MRI，其中，30例还经Gd—DTPA增强MRI。回顾性分析其MRI表现。结果在35例的MR像上，室管膜瘤12例，脉络丛乳头状瘤7例，血管母细胞瘤6例，髓母细胞瘤5例，转移瘤2例，星形细胞瘤2例，表皮样囊肿Ⅰ例。结论磁共振成像（MRI）对四脑室区肿瘤能清楚显示其部位、形态、生长方式及与周围结构的关系，因而具有很高的临床诊断价值。     

Value of magnetic resonance imaging for the diagnosis of ovarian tumors: a review

This article reviews the value of magnetic resonance imaging (MRI) for the diagnosis of ovarian tumors especially when ultrasonography is indeterminate. Although ultrasonography is the first imaging technique used to investigate suspected pelvic masses, it has a limited capacity for tissue characterization. In addition to morphological characteristics, many tissue parameters such as T1, T2, perfusion, and diffusion contribute to signal intensity, so MRI is able to identify various types of tissue contained in pelvic masses. Magnetic resonance imaging helps to locate large solid masses and to distinguish benign from malignant ovarian tumors, with an overall accuracy of 88% to 93% for the diagnosis of malignancy. The aims of this review are 3-fold. First, we review state-of-the-art and usual MRI techniques and published findings. Second, we recall the MR features most useful for assessing the main ovarian tumors. Finally, we discuss the relevance of various features for distinguishing between benign, borderline, and invasive ovarian tumors.     

MRI of anterior mediastinal tumors.

To compare the abilities of MRI (magnetic resonance imaging) and CT to provide information about anterior mediastinal tumors, we retrospectively evaluated the MR (n = 28) and CT images (n = 25) of patients with anterior mediastinal tumors. T1-weighted and T2-weighted images were obtained with spin echo sequences using cardiac gating. Six of 12 thymomas and seven of nine teratomas showed characteristic findings by MRI, while four of the 10 thymomas and five of the eight teratomas were correctly diagnosed by CT. The other tumors did not show a characteristic MR appearance. All nine malignant tumors were correctly diagnosed as malignant lesions on MR images, while one false positive case and one false negative case were recorded on CT images. We conclude that MRI and CT provide nearly the same information for the evaluation of anterior mediastinal tumors. However, in some cases, only MRI can provide information about malignancy or a specific diagnosis.     

颅内原发胶质肉瘤的MRI影像表现

目的分析颅内胶质肉瘤的MRI影像特征,以及这些影像特征在与颅内其他常见原发肿瘤鉴别诊断中的意义。资料与方法回顾性分析本院1998年4月至2011年4月9例经病理证实的胶质肉瘤患者的MRI影像表现、病理结果及临床表现。患者年龄30～66岁,平均48岁,所有患者均经手术切除及病理证实。9例患者均行常规T1WI、T2WI及增强扫描,部分患者行液体衰减反转恢复(FLAIR)、扩散加权成像(DWI)、扩散张量成像(DTI)及扩散张量纤维束成像(DTT)扫描。结果本组9例胶质肉瘤均发生在幕上。MRI平扫,肿瘤表现为边界清楚、均匀性或囊实性占位,伴有中重度水肿。T1WI上多呈低信号,T2WI上多呈高信号,FLAIR图像上,4例表现为高信号。增强扫描,多为明显环形强化。结论胶质肉瘤影像学表现具有一定特征,MRI能清晰显示病变,但与颅内其他原发肿瘤鉴别较困难,多序列成像有助于其鉴别诊断及预后的估计,确诊仍需病理检查。     

Noninvasive diagnosis of small cavernous hemangioma of the liver: advantage of MRI

Thirty-three lesions of small cavernous hemangioma of the liver under 3 cm in diameter detected by sonography, computed tomography (CT), or magnetic resonance imaging (MRI) were reviewed. Sonography detected 23 lesions, plain CT 15 out of 26, and MR 31, including one equivocal. On sonography, 18 of 23 revealed a strong, almost homogeneous hyperechoic mass without a rim. On CT, eight of 33 showed characteristic findings of hemangioma by contrast enhancement. On MRI, 26 of 31 appeared as a markedly high-intensity area, which was rarely the appearance of other hepatic tumors of similar size. Spin-spin relaxation time (T2) of hemangioma was prolonged over 80 msec in 15 of 18 while one of 20 lesions in patients with primary or secondary liver cancers under 3 cm showed T2 of 80 msec or more. MRI in addition to sonography and/or CT allowed detection of almost all cavernous hemangiomas over 1 cm in diameter and diagnosis with considerably high accuracy and specificity. MRI will play an important role in determination of necessity of further invasive diagnostic methods for patients with small liver tumors detected by sonography and/or CT.     

Borderline ovarian malignancy: ultrasound and fast dynamic MR findings

Ovarian tumors of borderline malignancy are low-grade malignant neoplasms, and have a rather good prognosis. They account for ≈10–20% of all ovarian tumors. Very few reports are available in literature that analyses ultrasound and MR findings in establishing the diagnosis. The purpose of this study is to describe eight cases of ovarian tumors of borderline malignancy with dynamic gadolinium-enhanced MR imaging. Comparison is made with CA 125 serum levels and ultrasound findings. Early enhancing endocystic vegetations, local cystic masses in, and (irregular) thickened walls of large multicystic tumors were important findings in borderline malignant tumors. The accuracy to detect a malignant tumor of borderline malignancy with CA 125, ultrasound and MRI in these eight cases was 50, 63 and 75%, respectively. MRI is a valuable imaging modality to characterize adnexal tumors and might play a role in preoperative evaluation of borderline malignancies.     

MRI和超声诊断肝内外胆管结石的ROC分析

目的:比较MRI和超声(US)在诊断肝内外胆管结石(BDS)中的价值.方法:收集2010年5月至2011年2月拟诊BDS的住院病例共136例,在我院同时行MRI和US,以手术发现为金标准比较两种检查方法诊断BDS的准确率、灵敏度和特异度;以及比较分析两种检查方法诊断BDS的受试者工作特征(ROC)曲线.结果:该136例中,82例行手术治疗.手术证实43例有肝内胆管结石(IHL),73例有肝外胆管结石(EHL),其中34例同时有肝内外胆管结石.MRI和US诊断IHL的灵敏度、特异度和准确率分别为93.0％、94.9％和93.9％,79.1％、94.9％和86.6％; MRI和US诊断EHL的灵敏度、特异度和准确率分别为65.8％、66.7％和65.9％,93.2％、77.8％和91.5％.MRI和US诊断IHL的ROC曲线下面积分别为0.971和0.964(P＞ 0.05);MRI和US诊断EHL的曲线下面积分别为0.855和0.776(P＜ 0.05).结论:在诊断IHL时,MRI与US诊断价值相当,而对于EHL,MRI明显优于US.     

Yolk sac tumor of the ovary: radiologic-pathologic correlation in four cases

We report the radiologic and pathologic features of yolk sac tumor (endodermal sinus tumor) of the ovary in four patients. Yolk sac tumors were shown as well-enhancing solid tumors on both CT and MR studies and were associated with prominent signal voids on MRI. A hypervascular nature was confirmed on microscopic studies. Areas of hemorrhage were another common characteristic. These imaging findings seem to have an important implication for the diagnosis of this tumor.     

颅内疑难肿瘤的MRI多序列图像分析

目的：提高MRI对颅内肿瘤的诊断准确率。方法：手术和病理证实的疑难病例13例，回顾性分析肿瘤的MRI图像特征。结果：13例中脑转移瘤7例，胶质母细胞瘤、胚胎发育障碍型神经上皮瘤、颅内淋巴瘤、海绵状血管瘤、丘脑脑膜瘤及蝶窦黏液表皮样癌各1例。结论：要提高MRI对颅内肿瘤的定性诊断准确率，需要了解转移瘤的发生部位及MRI表现的多样性，同时加强对少见病的认识。