不同型号小线圈水模的MRI特征  

MRI features of different sizes of small coil using a water phantom

作　　者：洪桂洵[1] 初建平[1] 饶良俊[1] 李树荣[1] 潘碧涛[1] 杨智云[1] 孟悛非[1] 

机构地区：[1]中山大学附属第一医院医学影像科,广州510080

出　　处：《中华放射学杂志》2014年第11期938-942,共5页Chinese Journal of Radiology

摘　　要：目的 探讨不同型号MR小线圈的成像特点,为临床应用提供参考.方法 利用内径分别为4、7及11 cm的Loop小线圈（简称为L4、L7、L11线圈）,对Siemens标配NiSO4·6H2O溶液水模进行MR成像.采集T1WI、T2WI、三维反转稳态自由快速进动DWI （3D-PSIF-DWI）和三维稳态进动快速成像压脂序列（3D-FISP-FS）图像,测量不同线圈各序列距线圈不同深度（分别为0、1、2、3、4、5、6、7、8、9、10、11、12、13 cm）的信号强度（SI）、标准差（SD）及信噪比（SNR）,并绘制深度-信号强度曲线及深度-信噪比曲线,比较不同线圈扫描获得图像的成像范围、SI及SNR变化.记录采用单独采用L11及与脊柱线圈联合应用图像的SNR,并采用秩和检验进行比较.结果 L4、L7小线圈在0.2-2.2cm范围内成像信号强度逐渐减低,在2.2- 4.2 cm保持较好的信号均匀度,L11线圈在5.2 cm范围内信号较均匀.L4、L7、L11小线圈最佳成像宽度分别为7.0、8.5、11.0cm.线圈直径增大,成像宽度、深度增加,接收的噪声亦增加,线圈中心至线圈边缘SNR逐渐减低.L11联合脊柱线圈使用,与单独采用L11相比,T1WI成像范围增加,但局部SNR减低,差异有统计学意义（Z=-2.354,P=0.019）.结论 临床上应根据受检部位个性化地选择相应型号的小线圈进行检查,并关闭其他线圈以提高SNR.Objective To explore the imaging characteristics of different sizes of MR small surface coil.Methods A water phantom with NiSO4· 6H2O for Siemens was scanned with 4 cm,7 cm and 11 cm small surface coils in Siemens 3.0 T MR system.T1WI,T2WI,three dimensional reversed fast imaging with steady state precession with diffusion-weighted（3D-PSIF-DWI） and three dimensional fast imaging with steady state precession and fat suppression（3D-FISP-FS） images were obtained.The imaging area,signal intensity （SI）,standard deviation （SD） and signal-to-noise ratio （SNR） variations of different depths （from the near to the distant） were measured and compared.Curves according to the SI and SNR data were draw.SI and SNR characteristics of images obtained by L11 separately and used together with spine matrix coil were compared by using signed rank sum test.Results The signal intensity of images scanned by 4 cm,7 cm small surface coil decreased gradually in the depth of 0.2 to 2.2 cm,maintain good signal uniformity in the depth of 2.2 to 4.2 cm,and the signal intensity obtained by 11 cm coil maintain good signal uniformity in the depth of 5.2 cm.The optimum imaging widths of 4 cm,7 cm and 11 cm coil were about 7.0,8.5 and 11.0 cm.As the diameter of the coil increased,the imaging width and depth increased,but the received noise also increased.The SNR gradually reduced from the center to the edge of the coils.The imaging area increased but the local SNR decreased when using L11 coil combine with spine matrix coil,which showed a statistically significant difference （Z=-2.354,P=0.019）.Conclusions A suitable size of small surface coil should be chosen according to the location and size of the organ or lesion before clinical MR examination.Other coils should be turned off to improve the SNR.

关 键 词：磁共振成像 线圈 对比研究 

分 类 号：R445.2[医药卫生—影像医学与核医学]