Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
Sci Rep. 2017 Oct 26;7(1):14115. doi: 10.1038/s41598-017-14581-9.
The goal of this paper was to evaluate the possibility of bi-component T1ρ and T2 relaxation mapping of human skeletal muscle at 3 T in clinically feasible scan times. T1ρ- and T2-weighted images of calf muscle were acquired using a modified 3D-SPGR sequence on a standard 3 T clinical MRI scanner. The mono- and biexponential models were fitted pixel-wise to the series of T1ρ and T2 weighted images. The biexponential decay of T1ρ and T2 relaxations was detected in ~30% and ~40% of the pixels across all volunteers, respectively. Monoexponential and bi-exponential short and long T1ρ relaxation times were estimated to be 26.9 ms, 4.6 ms (fraction 22%) and 33.2 ms (fraction: 78%), respectively. Similarly, the mono- and bi-exponential short and long T2 relaxation times were 24.7 ms, 4.2 ms (fraction 15%) and 30.4 ms (fraction 85%) respectively. The experiments had good repeatability with RMSCV < 15% and ICC > 60%. This approach could potentially be used in exercise intervention studies or in studies of inflammatory myopathies or muscle fibrosis, permitting greater sensitivity and specificity via measurement of different water compartments and their fractions.
本文旨在评估在临床可行的扫描时间内在 3T 下对人体骨骼肌进行双组份 T1ρ 和 T2 弛豫映射的可能性。使用标准 3T 临床 MRI 扫描仪上的改良 3D-SPGR 序列获取小腿肌肉的 T1ρ 和 T2 加权图像。分别对单指数和双指数模型进行逐像素拟合，以拟合 T1ρ 和 T2 加权图像系列。在所有志愿者中，分别约有 30%和 40%的像素检测到 T1ρ 和 T2 弛豫的双指数衰减。单指数和双指数 T1ρ 短和长弛豫时间分别估计为 26.9ms、4.6ms（分数 22%）和 33.2ms（分数 78%）。类似地，单指数和双指数 T2 短和长弛豫时间分别为 24.7ms、4.2ms（分数 15%）和 30.4ms（分数 85%）。该实验具有良好的可重复性，RMSCV<15%，ICC>60%。该方法可用于运动干预研究或炎性肌病或肌肉纤维化的研究，通过测量不同的水腔及其分数，提高了灵敏度和特异性。
