Brown Ryan, Khegai Oleksandr, Parasoglou Prodromos
Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.
Sci Rep. 2016 Jul 28;6:30568. doi: 10.1038/srep30568.
Magnetic resonance imaging (MRI) provides the unique ability to study metabolic and microvasculature functions in skeletal muscle using phosphorus and proton measurements. However, the low sensitivity of these techniques can make it difficult to capture dynamic muscle activity due to the temporal resolution required for kinetic measurements during and after exercise tasks. Here, we report the design of a dual-nuclei coil array that enables proton and phosphorus MRI of the human lower extremities with high spatial and temporal resolution. We developed an array with whole-volume coverage of the calf and a phosphorus signal-to-noise ratio of more than double that of a birdcage coil in the gastrocnemius muscles. This enabled the local assessment of phosphocreatine recovery kinetics following a plantar flexion exercise using an efficient sampling scheme with a 6 s temporal resolution. The integrated proton array demonstrated image quality approximately equal to that of a clinical state-of-the-art knee coil, which enabled fat quantification and dynamic blood oxygen level-dependent measurements that reflect microvasculature function. The developed array and time-efficient pulse sequences were combined to create a localized assessment of calf metabolism using phosphorus measurements and vasculature function using proton measurements, which could provide new insights into muscle function.
磁共振成像（MRI）具有独特的能力，可通过磷和质子测量来研究骨骼肌中的代谢和微血管功能。然而，由于运动任务期间及之后进行动力学测量所需的时间分辨率，这些技术的低灵敏度可能使得难以捕捉动态肌肉活动。在此，我们报告了一种双原子核线圈阵列的设计，该阵列能够以高空间和时间分辨率对人体下肢进行质子和磷MRI检查。我们开发了一种覆盖小腿全容积的阵列，其在腓肠肌中的磷信噪比是鸟笼线圈的两倍多。这使得能够使用具有6秒时间分辨率的高效采样方案，对跖屈运动后磷酸肌酸的恢复动力学进行局部评估。集成的质子阵列显示出的图像质量与临床最先进的膝关节线圈大致相当，这使得能够进行脂肪定量以及反映微血管功能的动态血氧水平依赖测量。所开发的阵列和高效脉冲序列相结合，可利用磷测量对小腿代谢进行局部评估，并利用质子测量对血管功能进行评估，这可为肌肉功能提供新的见解。
