影响脂肪肝MR波谱分析结果因素的研究

Study of the Factors Affecting the 1H MR Spectroscopy Imaging of Fatty Liver.

目的:探讨影响脂肪肝1H-MRS成像的相关技术因素。方法:对13例脂肪肝病例及7例健康志愿者行常规MR扫描及MR波谱成像。分析自动预扫描、感兴区的选择、饱和带的使用、高阶匀场等技术因素对脂肪肝MR波谱分析结果的影响。结果:做自动预扫描、使用饱和带和高阶匀场、调节定位、使感兴趣区远离骨质和气体,有19例(95%)波谱正常,呈左高右低的原始波谱曲线,曲线通过校准和后处理,呈现代表水峰和脂肪峰的波谱线。未做自动预扫描、未使用饱和带和高阶匀场,有2例(10%)出现化学物质的峰线过宽;其余18例中,3例(15%)出现波谱曲线的基线呈明显的锯齿状;12例(60%)出现整个波谱曲线呈锯齿状,没有任何化学物质的尖峰,3例(15%)扫描失败,18例均无法进行图像校准和后处理。结论:自动预扫描、使用饱和带和高阶匀场,同时调节定位,使感兴区远离骨质和气体是决定波谱采集成功与否的重要因素。

Objective：To study the factors affecting the ^1 H MR spectroscopy imaging of fatty liver. Methods： 12 patients with fatty liver and 7 normal subjects as the contrast group underwent MR scan without contrast administration and ^1H MRS imaging. The effects of autoprescan,selection of regions of interest （ROI）, application of saturation zone,and the well distributed field were analyzed. Results.. When using autoprescan, saturation zone, well-distributed field, after adjusting the position, making the ROI to be away from bone and gas, the spectroscopy curve was normal in 19 cases（95%）, showing a primitive spectroscopy curve （high left low right）. After post-processing and correction with spectroscopy analysis software,only H2O and lipid peaks were shown. For the cases had neither auto-prescan and saturation zone,nor well distributed field,the peak curves were wide in 2 cases （10%）. For the other 18 cases,the essential peak curves showed obvious serra tion in 3 cases （15%）：all of the peak curves were serrated in12 cases（60%）, and without peak for any chemical substance. Study couldn＇t be carried out in 3 cases（15%） ,all of the above- mentioned curves couldn＇t be corrected and post-processed. Conclusion： Using autoprescan,saturation zone,well distributed field,and after adjusting the position,making the regions of interest to be away from bone and gas,which are important in the successful acquisition of^1 H-MRS imaging.