Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA.
Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.
Magn Reson Med. 2021 Jun;85(6):3318-3325. doi: 10.1002/mrm.28673. Epub 2021 Jan 26.
To demonstrate a proof of concept for the measurement of myocardial oxygen extraction fraction (mOEF) by a cardiovascular magnetic resonance technique.
The mOEF measurement was performed using an electrocardiogram-triggered double-echo asymmetric spin-echo sequence with EPI readout. Seven healthy volunteers (22-37 years old, 5 females) were recruited and underwent the same imaging scans at rest on 2 different days for reproducibility assessment. Another 5 subjects (23-37 years old, 4 females) underwent cardiovascular magnetic resonance studies at rest and during a handgrip isometric exercise with a 25% of maximal voluntary contraction. Both mOEF and myocardial blood volume values were obtained in septal regions from respective maps.
The reproducibility was excellent for the measurements of mOEF in septal myocardium (coefficient of variation: 3.37%) and moderate for myocardial blood volume (coefficient of variation: 19.7%). The average mOEF and myocardial blood volume of 7 subjects at rest were 0.61 ± 0.05 and 11.0 ± 4.3%, respectively. The mOEF agreed well with literature values that were measured by PET in healthy volunteers. In the exercise study, there was no significant change in mOEF (0.61 ± 0.06 vs 0.62 ± 0.07) or myocardial blood volume (12 ± 6% vs 13 ± 4%) from rest to exercise, as expected.
The implemented cardiovascular magnetic resonance method shows potential for the quantitative assessment of mOEF in vivo. Future technical work is needed to improve image quality and to further validate mOEF measurements.
通过心血管磁共振技术证明心肌氧摄取分数（mOEF）测量的概念验证。
使用心电图触发的双回波不对称自旋回波序列进行 mOEF 测量，采用 EPI 读取。招募了 7 名健康志愿者（22-37 岁，5 名女性），并在 2 天的不同时间进行了相同的成像扫描，以评估重复性。另外 5 名志愿者（23-37 岁，4 名女性）在休息和进行握力等长运动时进行了心血管磁共振研究，等长运动时的收缩力为最大自主收缩力的 25%。分别从相应的地图中获得室间隔区域的 mOEF 和心肌血容量值。
室间隔心肌 mOEF 的测量重复性极好（变异系数：3.37%），心肌血容量的测量重复性中等（变异系数：19.7%）。7 名志愿者在休息时的平均 mOEF 和心肌血容量分别为 0.61 ± 0.05 和 11.0 ± 4.3%。mOEF 与通过 PET 在健康志愿者中测量的文献值吻合良好。在运动研究中，mOEF（0.61 ± 0.06 与 0.62 ± 0.07）或心肌血容量（12 ± 6%与 13 ± 4%）从休息到运动均无显著变化，符合预期。
所实现的心血管磁共振方法具有在体内定量评估 mOEF 的潜力。未来需要进行技术工作来提高图像质量，并进一步验证 mOEF 测量值。
