排序方式: 共有99条查询结果,搜索用时 20 毫秒
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目的 探讨6种特征性MRI征象对中枢神经细胞瘤的诊断价值。方法 回顾性分析30例中枢神经细胞瘤及68例其他侧脑室肿瘤患者术前MRI,以5分法对6种MRI征象,包括扇贝征、宽基底征、皂泡征、周围泡泡征、液-液平面征及宝石征进行评分。绘制ROC曲线,评估各征象的诊断价值。结果 扇贝征曲线下面积(AUC)最大(0.82),大于其他5个征象(P均<0.05);宽基底征、皂泡征及周围泡泡征次之(AUC为0.73~0.75),大于液-液平面征及宝石征(P均<0.05)。扇贝征特异度最高(84.56%),其次为液-液平面征(77.94%)、宝石征(74.26%)及周围泡泡征(70.34%)。皂泡征敏感度最高(83.89%),其次为宽基底征(76.11%)和周围泡泡征(75.00%)。结论 6种特征性MRI征象中,扇贝征对诊断中枢神经细胞瘤价值最高。 相似文献
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目的探讨3.0T多模态磁共振成像(MRI)在评估胶质瘤瘤体微观结构中的价值。方法收集经病理证实的胶质瘤患者36例,接受多模态MRI扫描扩散加权成像(DWI)、灌注加权成像(PWI)及扩散张量成像(DTI),并与病理结果对照,比较不同级别胶质瘤表观扩散系数(ADC)值、部分各向异性分数(FA)值和相对脑血容量(rCBV)值的差异,Pearson相关分析法检测胶质瘤瘤体ADC值、FA值和rCBV值与VEGF阳性细胞百分比及细胞密度的相关性。结果高级别胶质瘤瘤体FA值和rCBV值高于低级别胶质瘤,ADC值明显低于低级别胶质瘤(P<0.05);胶质瘤瘤体FA值、rCBV值与VEGF阳性细胞百分比及细胞密度呈正相关,ADC值与VEGF阳性细胞百分比及细胞密度均呈负相关。结论多模态MRI参数ADC值、FA值和rCBV值可为术前评估胶质瘤瘤体微观结构特点提供重要参考,间接反映肿瘤血管新生和细胞密度,其中以rCBV值优势明显。 相似文献
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目的观察脊柱外周型原始神经外胚层肿瘤(pPNET)的影像学表现。方法回顾性分析7例经病理证实的脊柱pPNET患者的影像学资料。结果 7例脊柱pPNET病例中,男性4例,女性3例。病变位于颈段(C2~7)1例,颈胸段(C7~T2)1例,胸段(T10~12)1例,腰段(L3~4、L4~5)2例,腰骶段(L1~S2)1例,骶段(S1~4)1例;其中,髓外硬膜内1例,硬膜外6例。MR(n=7)和CT(n=4)检查表现为硬膜内或硬膜外肿块,信号/密度不均,T1WI为等或稍低信号,T2WI为稍高信号,CT为等密度,增强扫描呈不同程度不均匀强化。肿瘤位于髓外硬膜内者可伴有多发蛛网膜下腔转移,硬膜外pPNET肿瘤的主体部分多位于椎骨或椎旁组织,肿块椎管内部分累及多个椎体平面,并通过椎间孔、骶孔与椎旁部分沟通。结论脊柱pPNET可表现为髓外硬膜内或硬膜外肿瘤,确诊依赖病理及免疫组化检查。 相似文献
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Objective: To establish a rodent model of VX2 tumor of the spleen, to analyze relationship between the change of the signal intensity on superparamagnetic iron oxide enhanced magnetic resonance image (MRI) and pathologic change to evaluate the ability of superparamagnetic iron oxide enhanced MRI for detection of splenic metastases. Methods: 8 rodent models of VX2 tumor of spleen were established successfully. The images were obtained before and after administration of superparamagnetic iron oxide. T1-weighted spin-echo (SE) pulse sequence with a repetition time (TR) of 450 msec, and echo time (TE) of 12 msec (TR/TE=450/12) was used. The imaging parameters of T2-weighted SE pulse sequence were as follows: TR/TE=4000/128. Results: On plain MR scanning T1-weighted splenic VX2 tumor showed hypointensity or isointensity which approximated to the SI of splenic parenchyma. Therefore all lesions were not displayed clearly. On superparamagnetic iron oxide enhancement T2WI sequence the SI of splenic parenchyma decreased obviously with percentage of signal intensity loss (PSIL) of 55.04%, But the SI of tumor was not evidently changed with PSIL of 0.87%. Nevertheless the SNR of normal splenic parenchyma around the lesions had obvious difference (P〈0.001) comparatively. Therefore the contrast between tumor and spleen increased, and tumor displayed more clearly. Moreover the contrast-to-noise (CNR) between VX2 tumor and splenic parenchyma had an evident difference before and after admininstration of superparamagnetic iron oxide (P〈0.001). Conclusion: On superparamagnetic iron oxide enhancement T1WI sequence the contrast of tumor-to-spleen is poor. Therefore it is not sensitive to characterize the lesions in spleen. On superparamagnetic iron oxide enhanced T2WI the contrast degree of lesions increases obviously. Consequently, superparamagnetic iron oxide -enhanced T2WI MRI scanning can improve the rate of detection and characterization for lesions of spleen. 相似文献
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超顺磁性氧化铁增强MRI检测转移性淋巴结的实验研究 总被引:8,自引:0,他引:8
目的:探讨超顺磁性氧化铁粒子(SPIO)增强MRI检测转移性淋巴结的价值。方法:取新西兰兔12只,6只于后腿肌肉接种VX2癌细胞,用于建立肿瘤转移性淋巴结模型;6只作为正常对照组。皮下间隙注射SPIO(每肢10μmol Fe),在注射前和注射后12h行MRI扫描,序列包括自旋回波(SE)T1WI、SE T2WI和梯度回波(GRE)T2WI,并与病理结果对照。结果:平扫时,正常淋巴结和VX2转移淋巴结在三个序列图像上均表现出相似的信号特点。在增强SE T1WI上,两组淋巴结的信号强度均未见变化;在增强SE T2WI上,正常淋巴结的信号强度不均匀降低,VX2转移组淋巴结的信号强度未见明显变化;在增强GRE T2WI上,正常淋巴结的信号强度明显地均匀降低,而VX2转移组有4个淋巴结信号强度未见降低,2个淋巴结不均匀降低。结论:SPIO增强MR成像可用于检测转移性淋巴结。 相似文献
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