INTRODUCTION Displacement encoding with stimulated echoes (DENSE) is a phase contrast technique that encodes tissue displacement into phase images, which are typically processed into measures of cardiac function such as strains. For improved signal to noise ratio and spatiotemporal resolution, DENSE is often acquired with a spiral readout using an 11.1 ms readout duration. However, long spiral readout durations are prone to blurring due to common phenomena such as off-resonance and T2* decay, which may alter the resulting quantifications of strain. We hypothesized that longer readout durations would reduce image quality and underestimate cardiac strains at both 3.0 T and 1.5 T and that using short readout durations could overcome these limitations. MATERIAL AND METHODS Computational simulations were performed to investigate the relationship between off-resonance and T2* decay, the spiral cine DENSE readout duration, and measured radial and circumferential strain. Five healthy participants subsequently underwent 2D spiral cine DENSE at both 3.0 T and 1.5 T with several different readout durations 11.1 ms and shorter. Pearson correlations were used to assess the relationship between cardiac strains and the spiral readout duration. RESULTS Simulations demonstrated that long readout durations combined with off-resonance and T2* decay yield blurred images and underestimate strains. With the typical 11.1 ms DENSE readout, blurring was present in the anterior and lateral left ventricular segments of participants and was markedly improved with shorter readout durations. Radial and circumferential strains from those segments were significantly correlated with the readout duration. Compared to the 1.9 ms readout, the 11.1 ms readout underestimated radial and circumferential strains in those segments at both field strengths by up to 19.6% and 1.5% (absolute), or 42% and 7% (relative), respectively. CONCLUSIONS Blurring is present in spiral cine DENSE images acquired at both 3.0 T and 1.5 T using the typical 11.1 ms readout duration, which yielded substantially reduced radial strains and mildly reduced circumferential strains. Clinical studies using spiral cine DENSE should consider these limitations, while future technical advances may need to leverage accelerated techniques to improve the robustness and accuracy of the DENSE acquisition rather than focusing solely on reduced acquisition time.

中文翻译：

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螺旋电影DENSE中的典型读数持续时间会产生模糊的图像，并低估3.0 T和1.5 T时的心脏应变。

简介带有刺激回声的位移编码（DENSE）是一种相衬技术，可将组织位移编码为相位图像，该图像通常被处理为心脏功能（例如应变）的量度。为了提高信噪比和时空分辨率，通常使用11.1 ms的读取持续时间通过螺旋式读取获得DENSE。但是，由于常见现象（例如，非共振和T2 *衰减）会导致较长的螺旋读数持续时间变得模糊，这可能会改变应变的结果。我们假设较长的读出持续时间会降低图像质量，并在3.0 T和1.5 T时低估心脏应变，并且使用较短的读出持续时间可以克服这些限制。材料与方法进行了计算仿真，以研究非共振与T2 *衰减，螺旋电影DENSE读出持续时间以及测得的径向和周向应变之间的关系。五名健康​​参与者随后分别以3.0 T和1.5 T进行了2D螺旋电影DENSE，其读出持续时间为11.1 ms或更短。皮尔逊相关性用于评估心脏应变与螺旋读数持续时间之间的关系。结果仿真表明，较长的读取时间与非共振和T2 *衰减相结合，会产生模糊的图像并低估应变。在典型的11.1 ms DENSE读数下，参与者的左前和外侧心室部段出现模糊，并且随着较短的读出时间而明显改善。这些段的径向和周向应变与读数持续时间显着相关。与1.9 ms的读数相比，11.1 ms的读数在两个场强下均低估了这些段中的径向应变和圆周应变，分别低了19.6％和1.5％（绝对值）或42％和7％（相对值）。结论使用典型的11.1 ms读出持续时间，在3.0 T和1.5 T下采集的螺旋电影DENSE图像中存在模糊，从而产生了显着减小的径向应变和适度减小的圆周应变。使用螺旋电影DENSE的临床研究应考虑这些局限性，而未来的技术进步可能需要利用加速技术来提高DENSE采集的鲁棒性和准确性，而不是仅仅着眼于缩短采集时间。