Medicine and Digitalization-MedDigit, Medical Faculty, University Department of Neurology, Otto von Guericke University, Magdeburg, Germany.
Department of Biomedical Magnetic Resonance, Otto von Guericke University, Magdeburg, Germany.
Magn Reson Med. 2022 Feb;87(2):646-657. doi: 10.1002/mrm.28998. Epub 2021 Aug 31.
Quantitative assessment of prospective motion correction (PMC) capability at 7T MRI for compliant healthy subjects to improve high-resolution images in the absence of intentional motion.
Twenty-one healthy subjects were imaged at 7 T. They were asked not to move, to consider only unintentional motion. An in-bore optical tracking system was used to monitor head motion and consequently update the imaging volume. For all subjects, high-resolution T (3D-MPRAGE), T (2D turbo spin echo), proton density (2D turbo spin echo), and (2D gradient echo) weighted images were acquired with and without PMC. The images were evaluated through subjective and objective analysis.
Subjective evaluation overall has shown a statistically significant improvement (5.5%) in terms of image quality with PMC ON. In a separate evaluation of every contrast, three of the four contrasts (T , T , and proton density) have shown a statistically significant improvement (9.62%, 9.85%, and 9.26%), whereas the fourth one ( ) has shown improvement, although not statistically significant. In the evaluation with objective metrics, average edge strength has shown an overall improvement of 6% with PMC ON, which was statistically significant; and gradient entropy has shown an overall improvement of 2%, which did not reach statistical significance.
Based on subjective assessment, PMC improved image quality in high-resolution images of healthy compliant subjects in the absence of intentional motion for all contrasts except , in which no significant differences were observed. Quantitative metrics showed an overall trend for an improvement with PMC, but not all differences were significant.
在 7T MRI 下对顺应性健康受试者的前瞻性运动校正（PMC）能力进行定量评估，以在没有故意运动的情况下改善高分辨率图像。
对 21 名健康受试者在 7T 下进行成像。要求他们不要移动，只考虑无意识运动。使用腔内光学跟踪系统来监测头部运动并相应地更新成像体积。对于所有受试者，使用和不使用 PMC 采集高分辨率 T（3D-MPRAGE）、T（2D 涡轮自旋回波）、质子密度（2D 涡轮自旋回波）和 T2（2D 梯度回波）加权图像。通过主观和客观分析评估图像。
主观评估总体显示，使用 PMC 时图像质量有统计学意义的提高（5.5%）。在对每种对比的单独评估中，四种对比中的三种（T1、T2 和质子密度）显示出统计学意义的提高（9.62%、9.85%和 9.26%），而第四种（T2）则显示出虽然没有统计学意义的提高。在使用客观指标的评估中，平均边缘强度显示使用 PMC 时整体提高了 6%，具有统计学意义；梯度熵显示整体提高了 2%，但没有达到统计学意义。
基于主观评估，PMC 改善了健康顺应性受试者在没有故意运动的情况下的高分辨率图像的图像质量，除了 T2 之外，所有对比度都有所改善，而在 T2 中则没有观察到显著差异。定量指标显示整体上有改善的趋势，但并非所有差异都具有统计学意义。
