Cardiac MRI tagging is a valuable technique for evaluating regional heart function. Currently, there are a number of different techniques for analyzing the tagged images. Specifically, k-space-based analysis techniques showed to be much faster than image-based techniques, where harmonic-phase (HARP) and sine-wave modeling (SinMod) stand as two famous techniques of the former group, which are frequently used in clinical studies. In this study, we compared HARP and SinMod and studied inter-observer variability between the two techniques for evaluating myocardial strain and apical-to-base torsion in numerical phantom, nine healthy controls, and thirty diabetic patients. Based on the ground-truth numerical phantom measurements (strain = -20% and rotation angle = -4.4°), HARP and SinMod resulted in overestimation (in absolute value terms) of strain by 1% and 5% (strain values), and of rotation angle by 0.4° and 2.0°, respectively. For the in-vivo results, global strain and torsion ranges were -10.6% to -35.3% and 1.8°/cm to 12.7°/cm in patients, and -17.8% to -32.7% and 1.8°/cm to 12.3°/cm in volunteers. On average, SinMod overestimated strain measurements by 5.7% and 5.9% (strain values) in the patients and volunteers, respectively, compared to HARP, and overestimated torsion measurements by 2.9°/cm and 2.5°/cm in the patients and volunteers, respectively, compared to HARP. Location-wise, the ranges for basal, mid-ventricular, and apical strain in patients (volunteers) were -8.4% to -31.5% (-11.6% to -33.3%), -6.3% to -37.2% (-17.8% to -33.3%), and -5.2% to -38.4% (-20.0% to -33.2%), respectively. SinMod overestimated strain in the basal, mid-ventricular, and apical slices by 4.7% (5.7%), 5.9% (5.5%), and 8.9% (6.8%), respectively, compared to HARP in the patients (volunteers). Nevertheless, there existed good correlation between the HARP and SinMod measurements. Finally, there were no significant strain or torsion measurement differences between patients and volunteers. There existed good inter-observer agreement, as all measurement differences lied within the Bland-Altman ± 2 standard-deviation (SD) difference limits. In conclusion, despite the consistency of the results by either HARP or SinMod and acceptable agreement of the generated strain and torsion patterns by both techniques, SinMod systematically overestimated the measurements compared to HARP. Under current operating conditions, the measurements from HARP and SinMod cannot be used interchangeably.

中文翻译：

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来自标记的MRI图像的区域心脏功能分析。技术比较：谐波相位（HARP）与正弦建模（SinMod）分析。

心脏MRI标签是评估区域心脏功能的宝贵技术。当前，有许多不同的技术用于分析标记图像。具体而言，基于k空间的分析技术比基于图像的技术要快得多，后者的谐波相位（HARP）和正弦波建模（SinMod）是前一组的两种著名技术，它们经常用于临床研究。在这项研究中，我们比较了HARP和SinMod，并研究了两种用于评估数字体模，9例健康对照和30例糖尿病患者的心肌应变和心尖至基端扭转的观察者之间的变异性。根据真实的数字体模测量（应变= -20％，旋转角度= -4.4°），HARP和SinMod分别导致应变（按绝对值计算）高估1％和5％（应变值），以及旋转角度分别高估0.4°和2.0°。对于体内结果，患者的总体应变和扭转范围分别为-10.6％至-35.3％和1.8°/ cm至12.7°/ cm，以及-17.8％至-32.7％和1.8°/ cm至12.3°/厘米的志愿者。平均而言，与HARP相比，SinMod分别高估了患者和志愿者的应变测量值5.7％和5.9％（应变值），而高估了患者和志愿者的扭力测量值2.9°/ cm和2.5°/ cm ，相比于HARP。就位置而言，患者（志愿者）的基础，心室中和心尖应变的范围为-8.4％至-31.5％（-11.6％至-33.3％），-6.3％至-37.2％（-17.8％）至-33.3％）和-5.2％至-38.4％（-20.0％至-33.2％）。与患者（志愿者）的HARP相比，SinMod高估了基底，心室中和心尖切片中的应变，分别为4.7％（5.7％），5.9％（5.5％）和8.9％（6.8％）。但是，HARP和SinMod测量之间存在良好的相关性。最后，患者和志愿者之间没有显着的拉力或扭力测量差异。观察者之间达成了良好的协议，因为所有测量差异均在Bland-Altman±2标准偏差（SD）差异限制之内。总之，尽管HARP或SinMod的结果具有一致性，并且两种技术都可以使产生的应变和扭转模式相一致，但与HARP相比，SinMod系统地高估了测量值。在当前的运行条件下，