Incorporation of Rician noise in the analysis of biexponential transverse relaxation in cartilage using a multiple gradient echo sequence at 3 and 7 Tesla.
Incorporation of Rician noise in the analysis of biexponential transverse relaxation in cartilage using a multiple gradient echo sequence at 3 and 7 Tesla.
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DOI：
10.1002/mrm.25111
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发表时间：
2015-01
影响因子：
3.3
通讯作者：
Spencer, Richard G.
中科院分区：
文献类型：
--
作者：
Bouhrara, Mustapha;Reiter, David A.;Celik, Hasan;Bonny, Jean-Marie;Lukas, Vanessa;Fishbein, Kenneth W.;Spencer, Richard G.
先前的工作评估了从表现出莱斯噪声的震级成像数据中提取弛豫时间的不同分析方法的质量。然而，组织（包括软骨和材料）松弛的双指数分析越来越引起人们的兴趣。因此，我们分析了莱斯噪声存在下的双指数横向弛豫衰减，并评估了几种确定成分分数和表观横向弛豫时间的方法的准确性和精确度。使用蒙特卡罗模拟以及模型和离体牛鼻软骨 (BNC) 实验对四种不同的逐体素拟合方法进行了比较。在每种情况下，我们都在一系列信噪比 (SNR) 范围内研究了 7T 和 3T 的临床前和临床成像场强以及参数。将结果与 Cramér-Rao 下限计算结果进行比较。正如预期的那样，在高信噪比下，所有方法都表现良好。在较低的 SNR 下，明确地拟合了保持性能的莱斯噪声的分析形式。 Gudbjartsson 和 Patz 的更有效的校正方案在许多情况下几乎表现得一样好。体模和 BNC 的离体实验与模拟结果一致。明确结合莱斯噪声极大地提高了双指数横向衰减数据分析的准确性和精度。
Previous work has evaluated the quality of different analytic methods for extracting relaxation times from magnitude imaging data exhibiting Rician noise. However, biexponential analysis of relaxation in tissue, including cartilage, and materials, is of increasing interest. We therefore analyzed biexponential transverse relaxation decay in the presence of Rician noise and assessed the accuracy and precision of several approaches to determining component fractions and apparent transverse relaxation times. Comparisons of four different voxel-by-voxel fitting methods were performed using Monte Carlo simulations, and phantom and ex-vivo bovine nasal cartilage (BNC) experiments. In each case, preclinical and clinical imaging field strengths of 7T and 3T, respectively, and parameters, were investigated across a range of signal-to-noise ratios (SNR). Results were compared to Cramér-Rao lower bound calculations. As expected, at high SNR, all methods performed well. At lower SNR, fits explicitly incorporating the analytic form of the Rician noise maintained performance. The much more efficient correction scheme of Gudbjartsson and Patz performed almost as well in many cases. Ex-vivo experiments on phantoms and BNC were consistent with simulation results. Explicit incorporation of Rician noise greatly improves accuracy and precision in the analysis of biexponential transverse decay data.
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影响因子：
14
作者：
Ghiassi-Nejad, M;Torzilli, PA;Pintar, MM
通讯作者：
Pintar, MM
影响因子：
3.8
作者：
EDELSTEIN, WA;BOTTOMLEY, PA;PFEIFER, LM
通讯作者：
PFEIFER, LM
影响因子：
2.9
作者：
Diaz, Eric;Chung, Christine B.;Du, Jiang
通讯作者：
Du, Jiang
影响因子：
3.3
作者：
Du, Jiang;Diaz, Eric;Bydder, Graeme M.
通讯作者：
Bydder, Graeme M.
影响因子：
2.9
作者：
Du, Jiang;Bydder, Graeme M.
通讯作者：
Bydder, Graeme M.