Englund Erin K, Berry David B, Behun John J, Ward Samuel R, Frank Lawrence R, Shahidi Bahar
Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, United States.
Department of Radiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
Front Rehabil Sci. 2022 May;3. doi: 10.3389/fresc.2022.910068. Epub 2022 May 31.
Quantification of the magnitude and spatial distribution of muscle blood flow changes following exercise may improve our understanding of the effectiveness of various exercise prescriptions. Intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) is a technique that quantifies molecular diffusion and microvascular blood flow, and has recently gained momentum as a method to evaluate a muscle's response to exercise. It has also been shown to predict responses to exercise-based physical therapy in individuals with low back pain. However, no study has evaluated the sensitivity of IVIM-MRI to exercise of varying intensity in humans. Here, we aimed to evaluate IVIM signal changes of the paraspinal muscles in response to moderate and high intensity lumbar extension exercise in healthy individuals.
IVIM data were collected in 11 healthy volunteers before and immediately after a 3-min bout of moderate and high-intensity resisted lumbar extension. IVIM data were analyzed to determine the average perfusion fraction (f), pseudo-diffusion coefficient (D*), and diffusion coefficient (D) in the bilateral paraspinal muscles. Changes in IVIM parameters were compared between the moderate and high intensity exercise bouts.
Exercise increased all IVIM parameters, regardless of intensity ( < 0.003). Moderate intensity exercise resulted in a 11.2, 19.6, and 3.5% increase in f, D* and D, respectively. High intensity exercise led to a similar increase in f (12.2%), but much greater changes in D* (48.6%) and D (7.9%).
IVIM parameter increases suggest that both the moderate and high-intensity exercise conditions elicited measurable changes in blood flow (increased f and D*) and extravascular molecular diffusion rates (increased D), and that there was a dose-dependence of exercise intensity on D* and D.
量化运动后肌肉血流变化的幅度和空间分布，可能会增进我们对各种运动处方有效性的理解。体素内不相干运动（IVIM）磁共振成像（MRI）是一种量化分子扩散和微血管血流的技术，最近作为一种评估肌肉对运动反应的方法而受到关注。它还被证明可以预测腰痛患者对运动疗法的反应。然而，尚无研究评估IVIM-MRI对不同强度人体运动的敏感性。在此，我们旨在评估健康个体中，中度和高强度腰椎伸展运动对椎旁肌IVIM信号的影响。
11名健康志愿者在进行3分钟的中度和高强度抗阻腰椎伸展运动前及运动后即刻，采集IVIM数据。分析IVIM数据，以确定双侧椎旁肌的平均灌注分数（f）、伪扩散系数（D*）和扩散系数（D）。比较中度和高强度运动组之间IVIM参数的变化。
无论运动强度如何，运动均增加了所有IVIM参数（<0.003）。中度强度运动使f、D和D分别增加了11.2%、19.6%和3.5%。高强度运动使f有类似增加（12.2%），但D（48.6%）和D（7.9%）的变化更大。
IVIM参数增加表明，中度和高强度运动条件均引起了血流（f和D增加）和血管外分子扩散率（D增加）的可测量变化，并且运动强度对D和D具有剂量依赖性。
