摘要
目的 研究正常大鼠的超顺磁性氧化铁 (SPIO)剂量梯度 肝脏信号曲线、大鼠种植型肝癌SPIO增强前后的对比噪声比和检出率。方法 第 1组 :72只正常SD大鼠随机分成 18个样本组 ,平扫后以 0、2、5…… 2 80 μmolFe/kg 18个SPIO剂量分别做增强扫描 ,做剂量梯度 肝脏信号曲线。第 2组 :38只种植型肝癌模型鼠 ,共计生成 43个肿瘤 ,行平扫及SPIO增强扫描 ,分析肿瘤磁共振强化特点 ;测量增强前后T1及T2 WI上的肿瘤 /肝脏对比噪声比 ,与病理对照统计平扫与增强的检出率。结果 在SPIO增强T2 及T1WI上 ,正常肝组织信号降至周围噪声水平的剂量分别为 10 μmolFe/kg及 40μmolFe/kg。以 2 0 μmolFe/kg剂量 ,增强T2 WI的肿瘤 /肝脏对比噪声比最好 ,几乎是增强T1WI及平扫T2 WI的 2倍 ,平扫T1WI的对比噪声比最差。SPIO增强MRI病灶检出率高达 10 0 %。在肿瘤小于 3mm组 ,平扫与增强检出率相差显著 ,其平扫漏检率达 36 .3%。结论 2 0 μmolFe/kg的SPIO剂量能同时获得良好的T2 、T1增强效果 ,其中T2 WI上肿瘤与肝脏对比最佳 。
Objective To make a curve of dose grads liver signal of superparamagnetic iron oxide (SPIO) in normal rats, to compare lesion to liver contrast noise ratio (C/N) and to assess the ability on MR imaging before and after SPIO injection. Methods Group one: 72 normal SD rats divided into 18 specimen groups at random, underwent MR enhancement with 0,2,5……280 μmol Fe/kg SPIO respectively after plain scanning. The signal to noise ratio of liver was measured and a curve of dose grads liver signal was made in order to find an appropriate dose for enhancement. Group two: 38 rats with 43 implanted liver adenocarcinomas underwent T 1 and T 2 weighted MR imaging before and after the injection of SPIO agent. Evaluations included enhancing characteristics of the tumors, counting the number of lesions and statistical analysis of quantitative changes in the signal intensity of both lesions and normal liver. Results On SPIO enhanced T 2 weighted and T 1 weighted MR images, the signal intensity of liver was reduced to peripheral noise on the dose of 10 μmol Fe/kg and 40 μmol Fe/kg respectively. The highest contrast to noise ratio (C/N) could be acquired on the dose of 20 μmol Fe/kg on enhanced T 2 weighted MR images; its C/N almost doubled compared with that of enhanced T 1 weighted and unenhanced T 2 weighted MR images. The C/N of unenhanced T 1 weighted MR images was lowest. The number of lesions detected on enhanced MR imaging was the same as that of the pathology, and enhanced MR imaging was superior to unenhanced MR imaging in tumors smaller than 3 mm, of 36.3% escaped detection on unenhanced MR images. Conclusion Good enhancement effect of SPIO on T 1 and T 2 weighted MR imaging could be acquired at the dose of 20 μmol Fe/kg, its detecting ability approached that of gross pathology, and the best contrast to noise ratio was found on T 2 weighted enhanced MR image.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2000年第12期805-810,共6页
Chinese Journal of Radiology
关键词
肝癌
实验研究
磁共振成像
超顺磁性氧化铁
Contrast media
Animals, laboratory
Liver neoplasms
Magnetic resonance imaging
