Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
J Magn Reson Imaging. 2011 May;33(5):1194-208. doi: 10.1002/jmri.22535.
To develop a bootstrap method to assess the quality of High Angular Resolution Diffusion Imaging (HARDI) data using Q-Ball imaging (QBI) reconstruction.
HARDI data were re-shuffled using regular bootstrap with jackknife sampling. For each bootstrap dataset, the diffusion orientation distribution function (ODF) was estimated voxel-wise using QBI reconstruction based on spherical harmonics functions. The reproducibility of the ODF was assessed using the Jensen-Shannon divergence (JSD) and the angular confidence interval was derived for the first and the second ODF maxima. The sensitivity of the bootstrap method was evaluated on a human subject by adding synthetic noise to the data, by acquiring a map of image signal-to-noise ratio (SNR) and by varying the echo time and the b-value.
The JSD was directly linked to the image SNR. The impact of echo times and b-values was reflected by both the JSD and the angular confidence interval, proving the usefulness of the bootstrap method to evaluate specific features of HARDI data.
The bootstrap method can effectively assess the quality of HARDI data and can be used to evaluate new hardware and pulse sequences, perform multifiber probabilistic tractography, and provide reliability metrics to support clinical studies.
开发一种基于 Q-Ball 成像（QBI）重建的自举法，以评估高角分辨率扩散成像（HARDI）数据的质量。
使用带有叉袋抽样的常规自举法对 HARDI 数据进行重洗牌。对于每个自举数据集，使用基于球谐函数的 QBI 重建来估计体素的扩散方向分布函数（ODF）。使用 Jensen-Shannon 散度（JSD）评估 ODF 的可重复性，并为第一和第二 ODF 最大值导出角度置信区间。通过向数据中添加合成噪声、获取图像信噪比（SNR）图以及改变回波时间和 b 值，在人体受试者上评估自举方法的灵敏度。
JSD 与图像 SNR 直接相关。JSD 和角度置信区间反映了回波时间和 b 值的影响，证明了自举法评估 HARDI 数据特定特征的有效性。
自举法可有效评估 HARDI 数据的质量，可用于评估新的硬件和脉冲序列、进行多纤维概率轨迹追踪，并提供可靠性指标以支持临床研究。
