腹部低场强MRI中的半扫描技术  

Half-scan Technique in Abdomen MRI on Lower-field Set

作　　者：胡永胜[1] 何新华[1] 高斌[1] 陈兵[1] 

机构地区：[1]安徽合肥市第一人民医院影像中心,230061

出　　处：《中国医学计算机成像杂志》2004年第3期178-181,共4页Chinese Computed Medical Imaging

摘　　要：目的探讨磁共振成像的半扫描技术在低场腹部扫描中的应用价值。材料和方法使用0.2T开放式永磁型MRI仪对20例患者进行腹部SE-T1WI序列扫描,均采用Half-scan技术,NSA分别为4、6、8,并同时完成非Half-scan技术、NSA4扫描作为对照。对上述4种图像的同一层面进行对比分析,包括SNR、运动伪影、图像质量及扫描时间。结果与对照相比,Half-scan技术4次采集的扫描时间明显缩短,6次采集的运动伪影抑制效果最佳(t=6.28,P<0.001)且扫描时间有所缩短,8次采集的伪影抑制效果较佳(t=3.25,P<0.01)但扫描时间有所增加。SNR间无明显统计学差异。结论低场MRI半扫描技术配合恰当的采集次数可显著抑制运动伪影,保证良好的SNR,缩短检查时间,从而获得优质的MR图像。Purpose:To evaluate the value of the half-scan technique in eliminated motion artifacts,improved image quality and shorten scan time.Materials and Methods:Selected SE imaging sequence and used of AIRIS mate(0.2T),20cases of abdomen MRI were taken4sorts of different scan sequences for T 1 WI:half-scan on,NSA=4,6,8(test method),Half-scan off,NSA=4(control method).Wrote down the scan times.The SNR of difference scan sequences were measured,motion artifacts and image quantitative analyses were performed for comparison of these sequences in same section and same location.Results:Compared with control method,the scan time on test method1(NSA=4)was the shortest;the effects of eliminated motion artifacts on test method2(NSA=6)were the best,motion artifacts were significantly smaller(t=6.28,P<0.001),the scan time was little shorter;motion artifacts on test method3(NSA=8)were significantly smaller too(t=3.25,P<0.01),but the scan time was longer.SNR were no sigˉnificant difference(P>0.05).Conclusion:Half-scan with increased NSA(half-scan,NSA=6)propˉerly could eliminate motion artifacts,improve image quality,shorten scan time significantly,therefore high quality image can be obtained.

关 键 词：腹部低场强 MRI 半扫描技术 MR图像 磁共振成像 图像质量 

分 类 号：R445.2[医药卫生—影像医学与核医学]