LeBlanc A, Evans H, Schonfeld E, Ford J, Schneider V, Jhingran S, Johnson P
Magn Reson Med. 1987 May;4(5):487-92. doi: 10.1002/mrm.1910040509.
Bed rest is used to simulate the effects of weightlessness on human physiology. A spin-echo procedure was used to image the lower leg of 15 normal male volunteers before and after 5 weeks of horizontal bedrest. In addition to noninvasively measuring muscle size changes, accurate T2 images were produced to investigate possible relaxation time changes immediately (2-4 h) and 1-2 days after bed rest. Subcutaneous fat showed no change in T2, bone marrow showed a decrease, and muscle showed no change immediately after bed rest but increased 1-2 days following reambulation.
卧床休息被用于模拟失重对人体生理的影响。采用自旋回波程序对15名正常男性志愿者在水平卧床休息5周前后的小腿进行成像。除了无创测量肌肉大小变化外，还生成了精确的T2图像，以研究卧床休息后即刻（2 - 4小时）以及1 - 2天后可能的弛豫时间变化。皮下脂肪的T2没有变化，骨髓T2降低，肌肉在卧床休息后即刻没有变化，但在重新行走1 - 2天后增加。
