摘要
目的 :研究正常大鼠肝脏磁共振的超顺磁性氧化铁 (SPIO)剂量梯度 -肝脏信号曲线 ,寻找合适的增强剂量。方法 :72只正常 SD大鼠随机分成 18个样本组 ,每组 4只。平扫后分别以 0、2、5、8、10、12、15、2 0、30、40、5 0、6 0、70、80、10 0、140、2 10、2 80μm ol/kg SPIO剂量行增强扫描 ,作剂量梯度 -肝脏信号曲线。结果 :(1)随着 SPIO剂量的增加 ,T1 及 T2 加权像肝脏的信号值均呈单向下降 ;(2 ) T2 加权像对小剂量 SPIO更为敏感 ,T1 加权像的 5 0 %有效剂量 (ED5 0 )为 8μmol/kg,而 T2 加权像的ED5 0 为 5μmol/kg;(3)在 15μm ol/kg剂量以上 ,T1 加权像信号值下降比例更大 ,其强化效果类似 T2 加权像 ,且图像更细腻 ;(4 ) T1 加权像在 40 μmol/kg剂量时肝脏信号接近周围噪声水平 ,而 T2 加权像在 15 μmol/kg剂量时肝脏信号即接近周围噪声水平。 结论 :重点观察 T1 加权序列及 T2 加权序列的 SPIO最佳剂量分别为 2 0 μmol/kg和 10 μmol/kg。
Objective: To establish a curve of dosage gradient liver signal intensity of superparamagnetic iron oxide (SPIO) in normal rats and to find an appropriate dose for enhancement. Methods: Seventy two SD rats, 4 rats a group at random, underwent MR enhancement with 0, 2, 5, 8, 10, 12, 15, 20, 30, 40, 50, 60, 70, 80, 100, 140, 210, 280 μmol/kg SPIO respectively after plane examination. The signal to noise ratio of liver was measured and a curve of dosage gradient liver signal intensity was made. Results: (1)With the increase of SPIO dose, the signal intensity of both T 1 and T 2 weighted images of liver declined. (2)T 2 weighted images was more sensitive than T 1 weighted images in small dose, the ED 50 of T 1 weighted was 8 μmol/kg, and the ED 50 of T 2 weighted was 5 μmol/kg. (3)When the dose was greater than 15 μmol/kg, the signal intensity of T 1 weighted images declined more rapidly than T 2 weighted, the effect of enhanced T 1 weighted images resembled T 2 weighted ones, and its images was with more fine resolution. (4)At the dose of 40 μmol/kg, the signal intensity of T 1 weighted images approached the background noise, and at the dose of 15 μmol/kg, the signal intensity of T 2 weighted images approached the background noise. Conclusion: Good effect of T 1 and T 2 enhanced MR imaging can be acquired at the dose of 20 10 μmol/kg SPIO respectively, the best contrast to noise ratio is found on T 2 weighted enhanced MR image. [
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2001年第4期343-345,共3页
Academic Journal of Second Military Medical University
基金
国家自然科学基金!资助项目 (39970 72 8)
