Empirical validation of gradient field models for an accurate ADC measured on clinical 3T MR systems in body oncologic applications.
Empirical validation of gradient field models for an accurate ADC measured on clinical 3T MR systems in body oncologic applications.
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在身体肿瘤学应用中，在临床3T MR系统上测量精确ADC的梯度场模型的经验验证。
DOI：
10.1016/j.ejmp.2021.05.030
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发表时间：
2021-06
期刊：
影响因子：
--
通讯作者：
Chenevert TL
中科院分区：
文献类型：
--
作者：
Pang Y;Malyarenko DI;Amouzandeh G;Barberi E;Cole M;Vom Endt A;Peeters J;Tan ET;Chenevert TL
以经验证实供应商提供的梯度非线性（GNL）特性，并证明3 T MR系统和空间位置上人脑表观扩散系数（ADC）的有效GNL偏差校正。在来自不同供应商的三个3 T MR平台上，使用表面基准阵列体模对单个梯度通道进行3D空间失真矢量场（DVF）标测。测量的DVF转换成经验的三维GNL张量，并与他们的理论同行来自供应商提供的球谐（SPH）系数进行比较。为了说明GNL对ADC的空间影响，使用三个正交梯度方向对定位在等中心（作为参考）并向上偏移10-17 cm（>10%预测GNL偏差）的志愿者大脑进行扩散加权成像。将基于SPH张量的GNL校正应用于单个DWI梯度方向，并将导出的ADC与人脑白色物质（WM）ROI的低偏差参考进行比较。经验和预测GNL误差是可比的所有三个研究的3 T MR系统，小于1.0%的差异，在中位数和宽度的空间直方图为个人GNL张量元素。ADC的中位数（±宽度）在三个MR系统的WM参考ROI中等中心点处测量的（10− 3 mm 2/s）直方图为：0.73±0.11，0.71±0.14，0.74±0.17，在非等中心点（GNL校正前与校正后）分别为0.63±0.14与0.72±0.11、0.53±0.16与0.74±0.18和0.65±0.16与0.76±0.18。基于体模的空间失真测量验证了供应商提供的梯度场，并且使用系统特定的基于张量的GNL校正进行常规DWI，无论空间位置和临床MR平台如何，都可以恢复准确的WM ADC。
To empirically corroborate vendor-provided gradient nonlinearity (GNL) characteristics and demonstrate efficient GNL bias correction for human brain apparent diffusion coefficient (ADC) across 3T MR systems and spatial locations. Spatial distortion vector fields (DVF) were mapped in 3D using a surface fiducial array phantom for individual gradient channels on three 3T MR platforms from different vendors. Measured DVF were converted into empirical 3D GNL tensors and compared with their theoretical counterparts derived from vendor-provided spherical harmonic (SPH) coefficients. To illustrate spatial impact of GNL on ADC, diffusion weighted imaging using three orthogonal gradient directions was performed on a volunteer brain positioned at isocenter (as a reference) and offset superiorly by 10–17 cm (>10% predicted GNL bias). The SPH tensor-based GNL correction was applied to individual DWI gradient directions, and derived ADC was compared with low-bias reference for human brain white matter (WM) ROIs. Empiric and predicted GNL errors were comparable for all three studied 3T MR systems, with less than 1.0% differences in the median and width of spatial histograms for individual GNL tensor elements. Median (±width) of ADC (10−3mm2/s) histograms measured at isocenter in WM reference ROIs from three MR systems were: 0.73±0.11, 0.71±0.14, 0.74±0.17, and at off-isocenters (before versus after GNL correction) were respectively 0.63±0.14 versus 0.72±0.11, 0.53±0.16 versus 0.74±0.18, and 0.65±0.16 versus 0.76±0.18. The phantom-based spatial distortion measurements validated vendor-provided gradient fields, and accurate WM ADC was recovered regardless of spatial locations and clinical MR platforms using system-specific tensor-based GNL correction for routine DWI.
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DOI：
10.1002/jmri.24883
发表时间：
2015-10
期刊：
Journal of magnetic resonance imaging : JMRI
影响因子：
--
作者：
Newitt DC;Tan ET;Wilmes LJ;Chenevert TL;Kornak J;Marinelli L;Hylton N
通讯作者：
Hylton N
DOI：
10.1016/j.ejmp.2018.08.013
发表时间：
2018-10-01
影响因子：
3.4
作者：
Sghedoni, Roberto;Coniglio, Angela;Giannelli, Marco
通讯作者：
Giannelli, Marco
影响因子：
3.3
作者：
Malyarenko, Dariya I.;Ross, Brian D.;Chenevert, Thomas L.
通讯作者：
Chenevert, Thomas L.
影响因子：
3.3
作者：
Janke, A;Zhao, HW;Doddrell, DM
通讯作者：
Doddrell, DM
影响因子：
3.3
作者：
Malyarenko, Dariya I.;Newitt, David;Chenevert, Thomas L.
通讯作者：
Chenevert, Thomas L.