Barbieri Sebastiano, Donati Olivio F, Froehlich Johannes M, Thoeny Harriet C
Department of Diagnostic, Pediatric, and Interventional Radiology, Inselspital University Hospital, Bern, Switzerland.
Department of Diagnostic and Interventional Radiology, University Hospital, Zürich, Switzerland.
Magn Reson Med. 2016 May;75(5):2175-84. doi: 10.1002/mrm.25765. Epub 2015 Jun 8.
To compare the variability, precision, and accuracy of six different algorithms (Levenberg-Marquardt, Trust-Region, Fixed-Dp , Segmented-Unconstrained, Segmented-Constrained, and Bayesian-Probability) for computing intravoxel-incoherent-motion-related parameters in upper abdominal organs.
Following the acquisition of abdominal diffusion-weighted magnetic resonance images of 10 healthy men, six distinct algorithms were employed to compute intravoxel-incoherent-motion-related parameters in the left and right liver lobe, pancreas, spleen, renal cortex, and renal medulla. Algorithms were evaluated regarding inter-reader and intersubject variability. Comparability of results was assessed by analyses of variance. The algorithms' precision and accuracy were investigated on simulated data.
A Bayesian-Probability based approach was associated with very low inter-reader variability (average Intraclass Correlation Coefficients: 96.5-99.6%), the lowest inter-subject variability (Coefficients of Variation [CV] for the pure diffusion coefficient Dt : 3.8% in the renal medulla, 6.6% in the renal cortex, 10.4-12.1% in the left and right liver lobe, 15.3% in the spleen, 15.8% in the pancreas; for the perfusion fraction Fp : 15.5% on average; for the pseudodiffusion coefficient Dp : 25.8% on average), and the highest precision and accuracy. Results differed significantly (P < 0.05) across algorithms in all anatomical regions.
The Bayesian-Probability algorithm should be preferred when computing intravoxel-incoherent-motion-related parameters in upper abdominal organs.
比较六种不同算法（列文伯格-马夸尔特算法、信赖域算法、固定扩散系数算法、分段无约束算法、分段约束算法和贝叶斯概率算法）在上腹部器官中计算体素内不相干运动相关参数时的变异性、精密度和准确性。
在获取10名健康男性的腹部扩散加权磁共振图像后，采用六种不同算法计算左、右肝叶、胰腺、脾脏、肾皮质和肾髓质中的体素内不相干运动相关参数。对算法进行了阅片者间和受试者间变异性的评估。通过方差分析评估结果的可比性。在模拟数据上研究了算法的精密度和准确性。
基于贝叶斯概率的方法具有非常低的阅片者间变异性（平均组内相关系数：96.5 - 99.6%），最低的受试者间变异性（纯扩散系数Dt的变异系数[CV]：肾髓质为3.8%，肾皮质为6.6%，左、右肝叶为10.4 - 12.1%，脾脏为15.3%，胰腺为15.8%；灌注分数Fp平均为15.5%；伪扩散系数Dp平均为25.8%），以及最高的精密度和准确性。在所有解剖区域中，不同算法的结果差异显著（P < 0.05）。
在上腹部器官中计算体素内不相干运动相关参数时，应首选贝叶斯概率算法。
