Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 9200942, Japan.
Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 9200942, Japan.
Magn Reson Imaging. 2020 Oct;72:42-48. doi: 10.1016/j.mri.2020.06.003. Epub 2020 Jun 16.
This study aimed to clarify exercise-induced changes in intravoxel incoherent motion (IVIM) parameters obtained from diffusion-weighted imaging (DWI) of the calf muscle, as well as the relationships between IVIM parameters, perfusion, and water content in muscle tissue.
Thirteen healthy volunteers underwent IVIM-DWI, arterial spin labeling (ASL), and multi-echo spin-echo T mapping of the right calf on a 3.0-T magnetic resonance imaging scanner before and after performing dorsiflexion exercise. From the data, we derived the perfusion-related diffusion coefficient (D), perfusion component fraction (F), blood flow parameter (FD), and restricted diffusion coefficient (D) in the tibialis anterior muscle. The muscle blood flow (MBF) and transverse relaxation time (T) were also calculated from the ASL and multi-echo spin-echo data, respectively. We compared the parameters measured before and after exercise and assessed the relationship of each IVIM-derived perfusion parameter (D, F, and FD) with MBF and each diffusion parameter (D and ADC) or F with T.
Notably, all these parameters were significantly increased after exercise. Before exercise, the FD exhibited a significant positive correlation with the MBF, whereas no significant correlation was observed between D or F and MBF. After exercise, both D and FD exhibited significant positive correlations with MBF, whereas F was not significantly correlated with MBF. Additionally, D was significantly correlated with T after exercise, but not before exercise. No significant correlations were found between ADC and T either before or after exercise.
The IVIM analyses before and after exercise enable the simultaneous evaluation of exercise-induced changes in perfusion and water diffusion in the muscle and increases the body of information on muscle physiology.
本研究旨在阐明小腿肌肉扩散加权成像（DWI）中体素内不相干运动（IVIM）参数的运动诱导变化，以及 IVIM 参数与肌肉组织中的灌注、血流和水含量之间的关系。
13 名健康志愿者在 3.0T 磁共振成像扫描仪上进行了右侧小腿的 IVIM-DWI、动脉自旋标记（ASL）和多回波自旋回波 T 映射，在进行背屈运动前后分别进行了这些检查。从数据中，我们推导出了胫骨前肌的灌注相关扩散系数（D）、灌注分量分数（F）、血流参数（FD）和受限扩散系数（D）。分别从 ASL 和多回波自旋回波数据计算出肌肉血流（MBF）和横向弛豫时间（T）。我们比较了运动前后测量的参数，并评估了每个 IVIM 衍生灌注参数（D、F 和 FD）与 MBF 以及每个扩散参数（D 和 ADC）或 F 与 T 的关系。
值得注意的是，所有这些参数在运动后均显著增加。运动前，FD 与 MBF 呈显著正相关，而 D 或 F 与 MBF 之间无显著相关性。运动后，D 和 FD 均与 MBF 呈显著正相关，而 F 与 MBF 无显著相关性。此外，运动后 D 与 T 呈显著正相关，但运动前无相关性。运动前后，ADC 与 T 之间均无显著相关性。
运动前后的 IVIM 分析可同时评估肌肉中灌注和水扩散的运动诱导变化，并增加对肌肉生理学的信息了解。
