GE1.5T430s MR频率饱和法与水脂分离法膝关节抑制脂肪图像比较分析

目的：传统抑脂方式都存在着各自的局限性,图像质量整体受限,本研究通过比较分析频率选择脂肪预饱和（Fat Saturation,Fatsat）法和水脂分离（Smartfat）法两种脂肪抑制序列在GE 1.5T optima 430 s关节磁共振上抑脂效果的成像质量、检查时间,以获得最佳的脂肪抑制序列图像.材料与方法：本研究应用GE l.5T 430s MR完成30个健康志愿者（男15,女15）膝关节脂肪抑制序列的检查.将同一患者分别用Fatsat法和Smartfat法扫描,即Fatsat T1WI、Fatsat T2WI、Fatsat PD和SmartfatT1WI、Smartfat T2WI、Smartfat PD,由2位经验丰富的影像科医生分别对两种脂肪抑制图像上的韧带、软骨、肌肉、半月板和图像均匀性的显示进行评价（将清晰列为3分,欠清晰为2分,模糊为1分）.采用t检验比较分析两种抑脂方法的抑脂效果图像质量、检查时间.采用Kappa检验评价2位阅片者间的诊断一致性.结果：30例志愿者两种检查方法均成功.Fatsat T1WI为（7.5±0.98）分,Smartfat T1WI为（12.2±1.51）分,Fatsat T2WI为（8.4±0.43）分,Smartfat T2WI为（15.1±0.75）分,Fatsat PD为（8.7±0.21）分,Smartfat PD为（12.3±0.81）分,差异有统计学意义.2位阅片者间的诊断一致性很好（Kappa值＞0.75）.结论：Smartfat法抑脂效果图像质量要大幅度优于Fatsat法,且检查时间相对较短.

A comparative study of Fatsat and Smartfat methods in fat suppression at knee joint on GE 1.5T optima 430 s MR system

Objective：All the traditional fat suppression methods have their own limitations,such as limitation of image quality,this study is through the comparative analysis of fat saturation technology of Fatsat and Smartfat methods for knee joint on GE 1.5T optima 430 s,to evaluate the fat suppression effect,MR image quality,examination time of the 2 methods in order to obtain the best optimal fat saturation technique.Materials and Methods：MR fat suppression sequences of the knee joints in 30 healthy volunteers were prospectively collected.There were 15 men and 15 women enrolled into this study,T1WI,T2WI,PD of bosh Fatsat and Smartfat were performed on each individual for comparison.The images of the ligament,cartilage,muscle,menisci and the signal uniformity,fat suppression effect and image quality were evaluated on each of these sequences by 2 experienced radiologists.The score of 3 points was indicated as image clear,2 points as image less clear,and 1 point as image blurred.Each radiologist evaluated 2 times,so 4 sets of evaluation data were obtained.Fat suppression effect,image quality,examination time of the two methods were compared using t-text analysis,and the diagnostic consistency of the two radiologists and the same radiologist at different time were evaluated using the kappa test.Result：Fatsat T1WI got 7.5±0.98 points,Smartfat T1WI got 12.2±1.51 points,Fatsat T2WI got 8.4±0.43 points,Smartfat T2WI got 15.1±0.75 points,Fatsat PD got 8.7±0.21 points,Smartfat PD got 12.3±0.43 points.The differences were statistically significant.The diagnostic consistency of the 2 radiologists was very good （kappa＞0.75）.The total examination time of Fatsat was （637±29.6） seconds,Smartfat was （600±25.6） seconds,the difference was statistically significant.Conclusion：The fat suppression effect and image quality of Smartfat sequence are substantially better than those of Fatsat,the examination time of Smartfat is relatively shorter than that of Fatsat.