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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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目的 对比分析下肢骨肉瘤的X线与MRI表现,探讨MRI对骨肉瘤的诊断价值。方法 收集经手术或病理穿刺活检证实的下肢骨肉瘤15例,男11例,女4例,均行MRI平扫及增强扫描(4例行CT扫描),并摄有X线平片,对其MRI征象与X线征象作逐一对比。结果 MRI及X线平片对下肢骨肉瘤的诊断准确率均为100%,MRI在显示病变范围、放射状骨针、Codman三角两层结构以及跳跃病灶等方面明显优于X线平片检查。结论 X线平片是诊断骨肉瘤最简便而实用的方法,但MRI可以更好的显示病变的范围,发现早期病变。 相似文献
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目的:制备Gd3+标记的二乙三胺五乙酸-白蛋白(钆喷替酸葡甲胺-白蛋白,Gd-DTPA-HSA),在动物实验中观察其淋巴结靶向强化效果,并探讨其潜在的应用价值。方法:①选定4个不同pH值的反应体系及不同的cDTPAa/HSA摩尔比率,测定不同反应条件下每个白蛋白分子上所结合的Gd3+离子数量,计算不同反应条件DTPA-HSA的偶联效率;②健康新西兰兔6只,平扫后在双侧后脚掌趾蹼间隙各注射0.2ml Gd-DTPA-HSA,给药后第30min、1h、3h扫描。相关参数与平扫时相同。测量增强前后窝淋巴结的信号强度并计算其强化率。结果:①在cDTPAa/HSA摩尔比相同的条件下,每分子HSA-DTPA结合的Gd3+数目和DTPA-HSA的偶联效率随着反应体系pH值的增高而增加;②在反应体系pH值一定的条件下,cDTPAa/HSA摩尔比为200:1的条件下每分子HSA-DTPA结合的Gd3+数量大于二者摩尔比为100:1时所结合的Gd3+数量,但前者的DTPA-HSA偶联效率低于后者;③经趾蹼间隙给药后,小腿淋巴管和窝淋巴结明显、均匀的强化。结论:pH=8.0的0.1M NaHCO3反应缓冲体系有利于HSA与DTPA的偶联反应。HSA-Gd-DTPA是一种有效的淋巴结特异性对比剂,能够靶向强化淋巴结。 相似文献
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目的:回顾性分析MRI对Ⅰ期子宫内膜癌的诊断价值与意义。方法:54例Ⅰ期子宫内膜癌患者均行MRI,分析肿瘤与子宫肌层在动态增强扫描不同时期的对比噪声比(CNR)和子宫肌层浸润深度,并与术后病理对照。结果:Ⅰa期6例(11%),Ⅰb期29例(54%),Ⅰc期19例(35%),MRI对肿瘤侵犯子宫体肌层<50%的诊断符合率为80%,对于子宫体肌层受累≥50%的诊断符合率为84%。肿瘤与子宫肌层在动态增强扫描延迟期的CNR差异具有显著性意义(P<0.001)。结论:MRI能够明确诊断子宫体肌层受侵犯的深度、范围,对于临床治疗有极大的帮助。 相似文献
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目的:建立大鼠脾脏VX2肿瘤模型,研究大鼠脾VX2肿瘤超顺磁性氧化铁(SPIO)增强MRI上信号强度变化与病理学改变之间的关系.探讨SPIO在大鼠脾脏转移瘤的应用价值.方法:对8只脾脏荷VX2肿瘤模型鼠;静脉注射SPIO后行MRI扫描,扫描序列采用T1WI(450/12 ms )和T2WI(4 000/128 ms ).结果:平扫SET1WI上肿瘤-脾脏的对比噪声比极差,所有病灶均不能很好显示.SPIO增强T2WI上正常脾实质信号强度明显降低,信号强度下降百分比(PSIL)为55.04%;脾脏VX2肿瘤信号强度无明显下降,PSIL为0.87%,与正常脾实质信号强度下降程度差异有统计学意义,t= 3.879,P<0.001.脾VX2肿瘤的CNR较增强前显著提高,t= 6.963,P<0.001.结论:SPIO增强T1WI 上正常脾实质与VX2肿瘤组织的对比差,病灶的检出率低,不利于描述病灶的特征.SPIO增强T2WI 上脾脏-肿瘤的对比显著,提高了病灶的检出率,改善了病灶影像学特征的描述. 相似文献
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