Signal to Noise Ratio and Uncertainty in Diffusion Tensor Imaging at 1.5, 3.0, and 7.0 Tesla
Signal to Noise Ratio and Uncertainty in Diffusion Tensor Imaging at 1.5, 3.0, and 7.0 Tesla
复制标题
DOI：
10.1002/jmri.22554
复制
发表时间：
2011-06-01
影响因子：
4.4
通讯作者：
Hoogduin, Johannes M.
中科院分区：
文献类型：
--
作者：
Polders, Daniel L.;Leemans, Alexander;Hoogduin, Johannes M.
目的：比较人体超高场强(7特斯拉[T])下的扩散张量成像(DTI)测量结果与1.5特斯拉和3特斯拉下的DTI测量结果。材料和方法：通过对9名志愿者在1.5T、3T和7T三种硬件配置下的感兴趣区域的声道成像测量，评估信噪比(SNR)和DTI参数拟合的不确定度分数各向异性和主特征向量。在7T时测得的信噪比增幅大于预期，仅从场强来看，这表明改进的接收线圈硬件对信噪比的影响很大。此外，当平均分数各向异性在不同场强下保持相对恒定时，分数各向异性和DTI张量的主特征向量拟合值的不确定性降低。在7T下观察到信号强度的空间异质性增加。结论：在目前的硬件限制下，超高场强下的DTI有可能改善所选感兴趣区的性能。
Purpose: To compare diffusion tensor imaging (DTI) measurements at ultra high field strength (7 Tesla [T]) in human volunteers with DTI measurements performed at 1.5 and 3 Tesla.Materials and Methods: The signal to noise ratio (SNR) and the uncertainty in fitted DTI parameters fractional anisotropy and primary eigenvector are assessed with tractography based regions of interest, measured in nine volunteers at 1.5T, 3T, and 7T with clinically available hardware configurations.Results: An increase in SNR is observed on the 7T system compared with the 1.5 or 3T system. The measured increase in SNR at 7T is larger than expected from field strength alone, indicating the large influence of improved receive coil hardware. Additionally, while the average fractional anisotropy remains relatively constant across field strengths, a decrease in uncertainty in the fitted values for fractional anisotropy and the principal eigenvector of the DTI tensor was found. Increased spatial heterogeneity of signal intensities is observed at 7T.Conclusion: Given the current hardware constraints, DTI at ultra-high field strengths is possible with improved performance in selected regions of interest.