杨艳 1董莘 1敖国昆 1吴宁 1刘杰爱 1许国宇 1韩顺霞 1常海峰1
作者信息
- 1. 解放军第309医院放射科 北京 100091
- 折叠
摘要
Abstract
Objective: To study the effects of flip angle (FA) to signal intensity of the liver parenchyma in liver specific period of Gd-EOB-DTPA MRC, and to determine reasonable delay time of liver specific period and scan sequence parameters. Methods:15 cases of patients took CT scan with FA value 9 degrees, 25 degrees, 30 degrees and 35 degrees in liver specific period of Gd-EOB-DTPA MRC after 5min,10min,15min and 20min. The resulting image of each FA value sum up as a group. The liver parenchyma, the erector spinae and the background signal intensity of each group were measured respectively. And the signal to noise ratio (SNR) and the contrast to noise ratio (CNR) of liver parenchyma, erector spinae about each group were calculated and analyzed by One-Way ANOVA among different groups. The subjective parameters including image artifacts, image uniformity, contrast ratio and whole image quality were analyzed by Kruskal-Wallis H test. According to the subjective evaluation results, we compared the CNR of liver parenchyma-erector spinae at 15min FA(25degrees) and 20min FA(9 degrees) which were calculated and analyzed by t test. There was significant difference (P<0.05). Results:For flip angle 9 degrees, 25 degrees, 30 degrees and 35 degrees, the SNR of liver parenchyma-erector were 150.33±9.06, 204.93±6.99, 210.76±11.87 and 219.98±8.31. There was significant difference (F=17.76, P=0.03). The subjective scores of image artifacts were 4.90±0.31, 4.70±0.56, 4.80±0.73 and 4.80±0.69 (x2=20.87, P=0.07). The image uniformity were 4.70±0.89, 4.60±0.41, 4.80±0.93 and 4.60±0.38(x2=29.63, P=0.06). The liver parenchyma-erector spinae contrast were 1.30±0.35, 2.60±0.44, 4.10±0.38 and 4.90±0.90 (x2=46.76, P=0.03). The whole image quality were 1.80±0.90, 2.40±0.94, 4.90±0.29 and 5.00±0.00(x2=43.23, P=0.02). Conclusion: Increased FA can effectively improve the liver parenchyma signal intensity. After 15 min’s injection, the 25 degree can shorten the delay time of the liver and gallbladder specific period.关键词
磁共振成像/反转角/钆塞酸二钠/肝胆特异期/信号强度Key words
Magnetic resonance imaging/Flip angle/Gadoxetic acid disodium/Specific period of liver and gallbladder/Signal intensity分类
医药卫生
