Partial volume correction for in vivo 23Na-MRI data of the human brain
Partial volume correction for in vivo 23Na-MRI data of the human brain
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DOI：
10.1016/j.neuroimage.2015.03.025
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发表时间：
2015-05-15
期刊：
影响因子：
5.7
通讯作者：
Nagel, Armin M.
中科院分区：
文献类型：
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作者：
Niesporek, Sebastian C.;Hoffmann, Stefan H.;Nagel, Armin M.
钠浓度是一个功能性细胞参数，绝对定量对于诊断目的可能很有意义。钠磁共振成像 (Na-23-MRI) 的准确性受到部分体积效应 (PVE) 的强烈影响。因此，我们的目的是建立Na-23-MRI的部分体积校正（PVC）方法。将现有的几何转移矩阵（GTM）校正方法从正电子发射断层扫描（PET）转移到Na-23-MRI，并在模型研究中进行测试。在第一次体内测量之前评估不同的参数以及配准和分割的准确性。使用密度适应径向脉冲序列在 B-0 = 7 T 下获得人脑体内钠数据集，标称空间分辨率为 (3 mm)(3)。对四名健康受试者进行了一项志愿者研究，测量部分体积 (PV) 校正的组织钠浓度 (TSC)，并通过内在校正控制进行验证。在体模研究中，PVC 算法产生了良好的校正性能，并将测量的钠浓度值与体模最小隔室中的预期值之间的差异减少了 11%，校正后 PVE 引起的平均差异为 5.7%。校正后的体内数据显示，所有志愿者所研究的隔室的 PVE 偏差均有所减少，导致两个单独的 CSF 隔室之间的差异平均从 36% 减少到 7.6%。校正后两个单独的脑脊液室（脑沟、侧脑室）、灰脑和白脑物质的绝对 TSC 分别为 129 +/- 8 mmol/L、138 +/- 4 mmol/L、48 +/- 1 mmol/L 和 43 +/- 3 mmol/L。所应用的 PVC 算法减少了定量 Na-23-MRI 中的 PV 偏差。需要准确、高分辨率的解剖数据来实现适当的 PVC。该算法和分割方法非常稳健，并且可以产生可重复的结果。 (C) 2015 Elsevier Inc. 保留所有权利。
The concentration of sodium is a functional cell parameter and absolute quantification can be interesting for diagnostical purposes. The accuracy of sodium magnetic resonance imaging (Na-23-MRI) is strongly biased by partial volume effects (PVEs). Hence our purpose was to establish a partial volume correction (PVC) method for Na-23-MRI.The existing geometric transfer matrix (GTM) correction method was transferred from positron emission tomography (PET) to Na-23-MRI and tested in a phantom study. Different parameters, as well as accuracy of registration and segmentation were evaluated prior to first in vivo measurements. In vivo sodium data-sets of the human brain were obtained at B-0 = 7 T with a nominal spatial resolution of (3 mm)(3) using a density adapted radial pulse sequence. A volunteer study with four healthy subjects was performed to measure partial volume (PV) corrected tissue sodium concentration (TSC) which was verified by means of an intrinsic correction control.In the phantom study the PVC algorithm yielded a good correction performance and reduced the discrepancy between the measured sodium concentration value and the expected value in the smallest compartments of the phantom by 11% to a mean PVE induced discrepancy of 5.7% after correction. The corrected in vivo data showed a reduction of PVE bias for the investigated compartments for all volunteers, resulting in a mean reduction of discrepancy between two separate CSF compartments from 36% to 7.6%. The absolute TSC for two separate CSF compartments (sulci, lateral ventricles), gray and white brain matter after correction were 129 +/- 8 mmol/L, 138 +/- 4 mmol/L, 48 +/- 1 mmol/L and 43 +/- 3 mmol/L, respectively.The applied PVC algorithm reduces the PV-bias in quantitative Na-23-MRI. Accurate, high-resolution anatomical data is required to enable appropriate PVC. The algorithm and segmentation approach is robust and leads to reproducible results. (C) 2015 Elsevier Inc. All rights reserved.