Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004; Department of Radiology, The fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning 110032, China.
Chinese Freestyle Skiing Aerials team, General Administration of Sport, Beijing 100050; Affiliated Sports School, Shenyang Sport University, Shenyang, Liaoning 110102, China.
Chin Med J (Engl). 2018 May 5;131(9):1045-1050. doi: 10.4103/0366-6999.230740.
Magnetic resonance (MR) imaging provides a unique, noninvasive diagnostic platform to quantify the physiological and biochemical variables of skeletal muscle at rest. This study was to investigate the difference in thigh skeletal muscles between snowboarding halfpipe athletes and healthy volunteers via multiparametric MR imaging.
A comparative study was conducted between 12 healthy volunteers and 14 snowboarding halfpipe athletes. MR scanning targeted the left leg at the level of the proximal thigh on a 3.0T MR system. The measured parameters compared between the two groups included T1, T2, T2* relaxation times, fat fraction (FF), and cross-sectional area (CSA) of the quadriceps femoris and the hamstring muscles. Statistical analysis was carried out using independent sample t-test. Interrater reliability was also assessed with intraclass correlation coefficients (ICCs).
It was statistically equivalent between two groups in age, body mass index, thigh circumference, calf circumference, systolic blood pressure, and resting heart rate (all P > 0.05). However, the T1 and T2 values of the hamstring muscles in the athlete group were found to be significantly shorter than those in control group (T1: 1063.3 ± 24.1 ms vs. 1112.0 ± 38.2 ms in biceps femoris, 1050.4 ± 31.2 ms vs. 1095.0 ± 39.5 ms in semitendinosus, 1053.1 ± 31.7 ms vs. 1118.4 ± 40.0 ms in semimembranosus, respectively; T2: 33.4 ± 0.7 ms vs. 36.1 ± 1.9 ms in biceps femoris, 34.6 ± 2.0 ms vs. 37.0 ± 1.9 ms in semitendinosus, 36.9 ± 1.5 ms vs. 38.9 ± 2.4 ms in semimembranosus, respectively; all P < 0.05) although T2* relaxation time was detected with no significant difference. The FF of the hamstring muscles was obviously less than the control group (5.5 ± 1.9% vs. 10.7 ± 4.7%, P < 0.001). In addition, the quadriceps' CSA in the athlete group was substantially larger than the control group (8039.0 ± 1072.3 vs. 6258.2 ± 852.0 mm, P < 0.001). Interrater reliability was excellent (ICC: 0.758-0.994).
Multiple MR imaging parameters indicated significant differences between snowboarding halfpipe athletes and healthy volunteers in the thigh skeletal muscles.
磁共振（MR）成像提供了一种独特的、非侵入性的诊断平台，可在休息时定量评估骨骼肌的生理和生化变量。本研究旨在通过多参数 MR 成像技术比较单板滑雪半管运动员和健康志愿者的大腿骨骼肌差异。
在 3.0T MR 系统上对 12 名健康志愿者和 14 名单板滑雪半管运动员的左腿进行对比研究。MR 扫描以大腿近端为目标。两组间比较的测量参数包括 T1、T2、T2*弛豫时间、脂肪分数（FF）和股四头肌及腘绳肌的横截面积（CSA）。采用独立样本 t 检验进行统计学分析。采用组内相关系数（ICC）评估组内一致性。
两组间在年龄、体重指数、大腿围、小腿围、收缩压和静息心率方面差异无统计学意义（均 P＞0.05）。然而，运动员组的腘绳肌 T1 和 T2 值明显短于对照组（T1：股二头肌 1063.3±24.1ms 比 1112.0±38.2ms，半腱肌 1050.4±31.2ms 比 1095.0±39.5ms，半膜肌 1053.1±31.7ms 比 1118.4±40.0ms；T2：股二头肌 33.4±0.7ms 比 36.1±1.9ms，半腱肌 34.6±2.0ms 比 37.0±1.9ms，半膜肌 36.9±1.5ms 比 38.9±2.4ms，均 P＜0.05），尽管 T2*弛豫时间无显著差异。腘绳肌的 FF 明显低于对照组（5.5±1.9%比 10.7±4.7%，P＜0.001）。此外，运动员组的股四头肌 CSA 明显大于对照组（8039.0±1072.3 比 6258.2±852.0mm，P＜0.001）。组内一致性良好（ICC：0.758-0.994）。
多种 MR 成像参数表明，单板滑雪半管运动员与健康志愿者的大腿骨骼肌存在显著差异。
