作者:陈建，王苇，何玲，袁红梅，杜先懋，李澄
【摘要】 目的 观察波谱空间定位和扫描参数对图像质量的影响，并初步小结应用要点。方法 对65例头颅检查的受检者行磁共振波谱扫描，有目的地改变感兴趣区域（ROI）的位置、大小和其他参数设置（FOV、频率矩阵、相位矩阵、预饱和带等），记录预扫描后系统显示的半高宽、水抑制程度等数值，并对扫描后显示的图像质量进行初步评价，探讨这些数值与波谱质量之间的关系。结果 65例患者中有60例波谱谱线形态较好，代谢物峰值位置正常；5例谱线形态变形，波峰漂移较大。记录的结果数据中：半高宽5～23，水抑制级别92～99。谱线形态较好的60例中，半高宽均在系统提示的范围内；5例谱线差的半高宽为7、9、16和23，水抑制级别为95、96、97。结论 获得高质量的波谱，需要较高的磁场均匀度，而半高宽是反映均匀度的一个重要指标。只有尽一切技术手段使得半高宽在系统提示的范围之内，才有可能获得好的谱线。
【关键词】 磁共振波谱学；半高宽；质量控制
Quality control and main techniques in MRS technology
【Abstract】 Objective To explore the effects on images from the space location of spectrum and scanning parameters'and summarize the technological essential and application hints.Methods 65 patients were scanned in brain with magnetic resonance spectroscopy'the location and the size of region of interesting （ROI） and other scanning parameters values （FOV'frequency matrix'phase matrix'saturate cingulum'etc.） were changed intentionally'the values of full width at half maxium and water suppression lever were recorded.A preliminary evaluation of the resulted waves and the relationship between the parameters data and the quality of the MRS waves were probed.Results Of the 65 cases'60 were with better shape of wave lines and metabolite peak positions'5 with aberrant lines and shifted peaks.Among the recorded data: the range of full width at half maxium value was 5～23'water suppression level was 92～99.In the 60-case group'all those full width at half maxium values were in the given range of the system'on the contrast'in the 5-case group full width at half maxium values were 7'9'16 and 23'and water suppression levels were 95'96'97.Conclusion High-quality wave spectrum depends on high uniformity of magnetic field.The value of full width at half maxium is an important factor that reflects the uniformity of magnetic field.Good wave spectrum lines only could be acquired with all those techniques which ensure the value of full width at half maxium to be within the given range of the system.
【Key words】 magnetic resonance spectroscopy; full width at half maxium;quality control
磁共振波谱（magnetic resonance spectroscopy'MRS）是一种非侵入方式显示组织代谢物质的含量并以谱线的形式反映其含量的技术，这些谱线所提供的信息有助于做出定量分析和定性诊断。MRS利用核磁共振中的化学位移和自旋耦合现象使含有同一种原子核的不同化合物中的不同分子集团在频率轴的不同位置被分别表现出来，它们构成了谱线的精细结构。目前利用MRS已经对多种原子核进行过测定并都已在临床上取得了一定的进展，不仅颅脑，在肝、肌肉及前列腺中也有应用，其中1H-MRS应用最多［1～5］。
影响波谱图像质量的因素很多，但只有正确精细的谱线才能准确地反映组织中代谢物的含量，否则就会使其反映的效果收之甚微，甚至误导诊断。因此，如何提高波谱图像的质量，使其对早期病变检出及对病变的范围及边缘做出准确判断，显得尤为重要。
1 资料与方法
1.1 一般资料 本组65例中男37例，女28例。年龄1～73岁，平均35.1岁。