Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705-2275, USA.
J Magn Reson Imaging. 2013 Apr;37(4):853-9. doi: 10.1002/jmri.23877. Epub 2012 Nov 2.
To compare pulse wave velocity (PWV) measurements obtained from radially undersampled 4D phase-contrast magnetic resonance imaging (PC-MRI) with 2D PC measurements and to evaluate four PWV algorithms.
PWV was computed from radially undersampled 3D, 3-directionally velocity-encoded PC-MRI (4D) acquisitions performed on a 3T MR scanner in 18 volunteers. High temporal resolution 2D PC scans serving as a reference standard were available in 14 volunteers. Four PWV algorithms were tested: time-to-upstroke (TTU), time-to-peak (TTP), time-to-foot (TTF), and cross-correlation (XCorr). Bland-Altman analysis was used to determine inter- and intraobserver reproducibility and to compare differences between algorithms. Differences in age and PWV measurements were analyzed with Student's t-tests. The variability of age-corrected data was assessed with a Brown-Forsythe analysis of variance (ANOVA) test.
2D (4.6-5.3 m/s) and 4D (3.8-4.8 m/s) PWV results were in agreement with previously reported values in healthy subjects. Of the four PWV algorithms, the TTU, TTF, and XCorr algorithms gave similar and reliable results. Average biases of +0.30 m/s and -0.01 m/s were determined for intra- and interobserver variability, respectively. The Brown-Forsythe test revealed that no differences in variability could be found between 2D and 4D PWV measurements.
4D PC-MRI with radial undersampling provides reliable and reproducible measurements of PWV. TTU, TTF, and XCorr were the preferred PWV algorithms.
比较从径向欠采样的 4D 相位对比磁共振成像（PC-MRI）获得的脉搏波速度（PWV）测量值与 2D PC 测量值，并评估四种 PWV 算法。
在 3T 磁共振扫描仪上对 18 名志愿者进行了径向欠采样的 3D、3 方向速度编码 PC-MRI（4D）采集，计算 PWV。在 14 名志愿者中可获得作为参考标准的高时间分辨率 2D PC 扫描。测试了四种 PWV 算法：上升时间（TTU）、峰值时间（TTP）、足时间（TTF）和互相关（XCorr）。Bland-Altman 分析用于确定观察者内和观察者间的可重复性，并比较算法之间的差异。使用学生 t 检验分析年龄和 PWV 测量值之间的差异。使用 Brown-Forsythe 方差分析（ANOVA）检验评估年龄校正数据的变异性。
2D（4.6-5.3 m/s）和 4D（3.8-4.8 m/s）PWV 结果与健康受试者的先前报道值一致。在四种 PWV 算法中，TTU、TTF 和 XCorr 算法得出了相似且可靠的结果。观察者内和观察者间可变性的平均偏差分别为+0.30 m/s 和-0.01 m/s。Brown-Forsythe 检验表明，2D 和 4D PWV 测量之间的变异性无差异。
径向欠采样的 4D PC-MRI 可提供可靠且可重复的 PWV 测量值。TTU、TTF 和 XCorr 是首选的 PWV 算法。
