Exercises to strengthen and stabilize the trunk musculature are a common conservative treatment strategy for low back pain (LBP), despite the possible presence of impairments in muscle activation in this population. Intravoxel incoherent motion (IVIM) MRI permits evaluation of activation-induced blood flow through diffusion-weighted images that are sensitized to microvascular blood flow. In the current study we aimed to evaluate IVIM signal changes after exercise in patients with LBP compared with pain-free healthy controls and determine if these changes were related to reductions in disability with a 12-week rehabilitation program. We hypothesize that the magnitude of changes in IVIM parameters in the lumbar extensor muscles will be smaller in patients with LBP compared with those without LBP, and that these magnitudes will be correlated with responsiveness to a 12-week, resistance-based exercise program. IVIM MR data for molecular diffusion (D), blood flow pseudodiffusion (D*) and perfusion fraction (f) were collected before and immediately after an ~ 3-min session of high-intensity lumbar extension resistance exercise in 16 healthy participants and 17 participants with LBP. Improvements in LBP-related disability after the 12-week, machine-based, high-intensity exercise rehabilitation program were measured in the LBP group. We observed a significant increase in all IVIM parameters (f, D*, D) in response to exercise (p < 0.0001) and an interaction of group-by-time for D (p = 0.016). Thresholds were identified using receiver operating characteristic (ROC) curves for diffusion and pseudodiffusion coefficients, which predicted a reduction in LBP-related disability in response to the 12-week, exercise-based rehabilitation program. Exercise was associated with an increase in (f), capillary blood flow-based pseudodiffusion (D*) and diffusion coefficient (D), regardless of the presence of LBP. Additionally, subgroup analysis identified patients who were not responsive to the acute exercise session, for whom, based on ROC analysis, there was no clinically significant change in disability following the 12-week program.

中文翻译：

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体素内不相干运动成像可预测腰痛患者基于运动的康复反应

尽管在该人群中可能存在肌肉激活障碍，但加强和稳定躯干肌肉组织的锻炼是腰痛 (LBP) 常见的保守治疗策略。体素内不相干运动 (IVIM) MRI 允许通过对微血管血流敏感的扩散加权图像评估激活诱导的血流。在目前的研究中，我们旨在评估与无痛健康对照组相比，LBP 患者运动后 IVIM 信号的变化，并确定这些变化是否与 12 周康复计划的残疾减少有关。我们假设与没有 LBP 的患者相比，有 LBP 的患者腰伸肌 IVIM 参数的变化幅度会更小，并且这些幅度将与对为期 12 周的基于阻力的锻炼计划的反应相关。在 16 名健康参与者和 17 名参与者进行约 3 分钟的高强度腰椎伸展阻力运动之前和之后立即收集分子扩散 (D)、血流假扩散 (D*) 和灌注分数 (f) 的 IVIM MR 数据与 LBP。在 LBP 组中测量了 12 周、基于机器的高强度运动康复计划后 LBP 相关残疾的改善情况。我们观察到所有 IVIM 参数（f、D*、D）在运动后显着增加（在 16 名健康参与者和 17 名 LBP 参与者进行约 3 分钟的高强度腰椎伸展阻力运动之前和之后立即收集血流假扩散 (D*) 和灌注分数 (f)。在 LBP 组中测量了 12 周、基于机器的高强度运动康复计划后 LBP 相关残疾的改善情况。我们观察到所有 IVIM 参数（f、D*、D）在运动后显着增加（在 16 名健康参与者和 17 名 LBP 参与者进行约 3 分钟的高强度腰椎伸展阻力运动之前和之后立即收集血流假扩散 (D*) 和灌注分数 (f)。在 LBP 组中测量了 12 周、基于机器的高强度运动康复计划后 LBP 相关残疾的改善情况。我们观察到所有 IVIM 参数（f、D*、D）在运动后显着增加（p  < 0.0001）和 D 的按时间分组的交互作用（p  = 0.016）。使用扩散和伪扩散系数的接受者操作特征 (ROC) 曲线确定阈值，该曲线预测 LBP 相关残疾的减少，以响应 12 周的基于运动的康复计划。无论是否存在 LBP，运动与 (f)、基于毛细血管血流的假扩散 (D*) 和扩散系数 (D) 的增加有关。此外，亚组分析确定了对急性锻炼没有反应的患者，根据 ROC 分析，在 12 周的项目后，这些患者的残疾没有临床上的显着变化。