Table_1_Amide Proton Transfer Contrast Distribution in Different Brain Regions in Young Healthy Subjects.DOCX

ObjectivesTo define normal signal intensity values of amide proton transfer-weighted (APTw) magnetic resonance (MR) imaging in different brain regions.
Materials and MethodsTwenty healthy subjects (9 females, mean age 29 years, range 19 – 37 years) underwent MR imaging at 3 Tesla. 3D APTw (RF saturation B1,rms = 2 μT, duration 2 s, 100% duty cycle) and 2D T2-weighted turbo spin echo (TSE) images were acquired. Postprocessing (image fusion, ROI measurements of APTw intensity values in 22 different brain regions) was performed and controlled by two independent neuroradiologists. Values were measured separately for each brain hemisphere. A subject was scanned both in prone and supine position to investigate differences between hemispheres. A mixed model on a 5% significance level was used to assess the effect of gender, brain region and side on APTw intensity values.
ResultsMean APTw intensity values in the hippocampus and amygdala varied between 1.13 and 1.57%, in the deep subcortical nuclei (putamen, globus pallidus, head of caudate nucleus, thalamus, red nucleus, substantia nigra) between 0.73 and 1.84%, in the frontal, occipital and parietal cortex between 0.56 and 1.03%; in the insular cortex between 1.11 and 1.15%, in the temporal cortex between 1.22 and 1.37%, in the frontal, occipital and parietal white matter between 0.32 and 0.54% and in the temporal white matter between 0.83 and 0.89%. APTw intensity values were significantly impacted both by brain region (p < 0.001) and by side (p < 0.001), whereby overall values on the left side were higher than on the right side (1.13 vs. 0.9%). Gender did not significantly impact APTw intensity values (p = 0.24). APTw intensity values between the left and the right side were partially reversed after changing the position of one subject from supine to prone.
ConclusionWe determined normal baseline APTw intensity values in different anatomical localizations in healthy subjects. APTw intensity values differed both between anatomical regions and between left and right brain hemisphere.

【研究目的】明确不同脑区的酰胺质子转移加权（amide proton transfer-weighted, APTw）磁共振（magnetic resonance, MR）成像的正常信号强度值。
【材料与方法】招募20名健康受试者（9名女性，平均年龄29岁，年龄范围19~37岁），于3特斯拉磁共振扫描仪上完成成像检查。采集序列包含三维APTw成像（射频饱和B1均方根值=2μT，持续时间2s，占空比100%）与二维T2加权涡轮自旋回波（turbo spin echo, TSE）图像。由两名独立的神经放射科医师完成图像处理（含图像融合、对22个不同脑区的APTw信号强度值开展感兴趣区（region of interest, ROI）测量）并进行质量控制。针对每个大脑半球分别测量信号强度值。1名受试者分别采用俯卧位与仰卧位完成扫描，以探究大脑半球间的信号差异。采用显著性水平为5%的混合效应模型，评估性别、脑区及大脑侧别对APTw信号强度值的影响。
【研究结果】海马体与杏仁核的平均APTw信号强度值介于1.13%~1.57%之间；深部皮层下核团（包括壳核、苍白球、尾状核头、丘脑、红核、黑质）的信号强度值介于0.73%~1.84%之间；额叶、枕叶及顶叶皮层的信号强度值介于0.56%~1.03%之间；岛叶皮层的信号强度值介于1.11%~1.15%之间；颞叶皮层的信号强度值介于1.22%~1.37%之间；额叶、枕叶及顶叶白质的信号强度值介于0.32%~0.54%之间；颞叶白质的信号强度值介于0.83%~0.89%之间。脑区（p<0.001）及大脑侧别（p<0.001）均对APTw信号强度值存在显著影响，整体而言左侧大脑的信号强度值高于右侧（1.13% vs 0.9%）。性别对APTw信号强度值无显著影响（p=0.24）。1名受试者改变体位（从仰卧位转为俯卧位）后，左右两侧的APTw信号强度值出现部分反转。
【研究结论】本研究明确了健康受试者不同解剖部位的APTw信号强度正常基线值。APTw信号强度值不仅存在解剖区域间的差异，同时也存在左右大脑半球间的差异。