目的 评估BaTiO3/CaTiO3制备的高介电常数(high dielectric constant,HDC)材料对7.0 T MRI小脑成像的改善效能.材料与方法 使用7.0 T MRI对10例受试者进行扫描,首先将HDC垫放在受试者枕后进行射频场场图(B1 map)、T2加权成像快速自旋回波序列(T2WI-turbo spin echo,T2WI-TSE)、T1磁化准备快速梯度回波成像(T1-magnetization prepared rapid gradient echo,T1-mprage)、扩散加权成像(diffusion weighted imaging,DWI)序列扫描(HDC垫组);任务结束后移除HDC垫,重复上述序列扫描方案作为对照组并进行结果比较.对同一人的两次数据进行端脑及小脑图像质量的评估,主观评估方法为Likert 5分量表法,客观评估方法为测量图像信噪比(signal-to-noise ratio,SNR).结果 10例受试者纳入研究[男5例,年龄27～34(30.60±2.58)岁;女5例,年龄26～32(29.20±2.99)岁].在小脑区域,主观评估中,HDC垫组T2WI-TSE和DWI序列的Likert 5评分均优于对照组(P<0.05);客观评估中,B1 map和T2WI-TSE序列采集图像的SNR均优于对照组(P<0.05).在端脑区域,B1 map、T2WI-TSE、T1-mprage和DWI序列主客观评估中差异均无统计学意义(P>0.05).结论 在7.0 T MRI应用中,HDC垫能够在不干扰端脑原有图像质量的情况下,提升小脑区域的成像质量,为7.0 T MRI小脑诊断及全脑研究提供了新的机会,同时也为其他部位的7.0 T MRI提供了优化思路.
Performance study of high dielectric constant materials to improve the effectiveness of 7.0 T MRI cerebellar imaging
Objective:To evaluate the efficacy of high dielectric constant(HDC)materials in improving the quality of 7.0 T MRI in cerebellar.Materials and Methods:Ten subjects were scanned using 7.0 T MRI,and firstly the HDC pad was placed on the occiput of each subject for B1 map,T2WI-turbo spin echo(T2WI-TSE),T1-mprage,and diffusion weighted imaging(DWI)sequence scanning.Then,the HDC pad was removed,and the above sequence scanning protocols were repeated.Comparisons were made between the results of using and not using HDC pad.To assess the quality of brain and cerebellar images of the same individual in two experiments,the Likert 5-point scale method was analyzed subjectively and changes in image signal-to-noise ratio(SNR)was quantified objectively.Results:Ten subjects[five males,27-34(30.60±2.58)years oid;five females,26-32(29.20±2.99)years old]were recruited in the present study.In cerebellar regions,the Likert 5 scores of T2WI-TSE and DWI sequences of the HDC pad group were better than the control group(P<0.05).In the objective assessment,the SNR of images acquired with B1 map and T2WI-TSE sequences were better than the control group(P<0.05).In brain regions,there were no statistical differences in the subjective and objective assessments of B1 map,T2WI-TSE,T1-mprage and DWI sequences(P>0.05).Conclusions:Applying the HDC pad in 7.0 T MRI can enhance the imaging quality of cerebellar regions without affecting the original image quality of the brain.It provides new opportunities for ultra-high field cerebellar diagnosis and research,as well as providing optimized strategies for ultra-high field imaging of other anatomical regions.
high dielectric constantcerebellumultrahigh magnetic field strengthssignal-to-noise ratiodielectric artifactmagnetic resonance imagingimage quality
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维普
