摘要
目的:探讨血池型MR对比剂Gd-DTPA-链霉亲和素对荷瘤裸鼠的MR强化模式。材料与方法:制备血池型MR对比剂Gd-DTPA-SA,测定其R1弛豫率。制作荷瘤裸鼠模型后,静脉注射Gd-DTPA-链霉亲和素进行MR扫描,测量SET1WI平扫及增强后30′、60′、3h、6h、12h、24h图像内肿瘤中心、肿瘤周边及肌肉组织的信号强度,绘制信号强度-时间曲线,并计算对比度噪声比。结果:Gd-DTPA-SA的体外R1弛豫率约为18.0l;(mmol·s)。静脉注射对比剂后,肿瘤表现为持续缓慢的强化方式,其中瘤周的强化峰值出现在注射对比剂6小时,其信号强度较平扫提高了54.3%,CNR值最大,与平扫有显著性差异(P<0.01)。肿瘤中心的最大强化时间出现在注射对比剂12小时,其信号强度较平扫提高了61.2%,随之强化程度降低,信号强度下降,但在24小时仍保持相对较高的信号强度。最后全瘤的信号强度趋于一致。而肌肉在各时间点的强化不明显。结论:Gd-DTPA-SA具有较大的R1弛豫率和较长的血液停留时间,具有应用价值,可对肿瘤微血管的渗透性和血管容量进行评估。
Objective： To evaluate MR enhanced characteristics of tumor using blood pool MR contrast agent Gd-DTPAstreptavidin. Methods： Measure R1 relaxation Tate of Gd-DTPA-SA after preparation. Fourteen nude mice bearing human hepatocelluar carcinoma were injected with Gd-DTPA-SA. MR scan was performed before and at 30min, 60min, 3h, 6h, 12h, and 24h after injection of MR contrast agents. Signal intensity of tumor core, rim and muscle on nonenhanced and enhanced images were measured to make enhancement time course. Contrast-to-noise of tumor was also calculated. Results： R1 relaxation rate of Gd-DTPA-SA was 18.01/（mmol·s）. After injection of Gd-DTPA-SA, the tumor demonstrated increasing signal with a stepwise pattern. At 6h after injection, enhanced ratio and CNR of tumor rim were largest, which had significant difference from other times. The signal intensity of tumor core showed the highest value at 12h after injection. But the muscle did not enhance significantly. Conclusion： Blood pool MR contrast agent Gd-DTPA-SA have potential value for evaluating microvessel permeability and blood volume of tumor.
出处
《中国临床医学影像杂志》
CAS
北大核心
2007年第1期53-55,共3页
Journal of China Clinic Medical Imaging
关键词
肝肿瘤
磁共振成像
liver neoplasms
magnetic resonance imaging
