Raymond Christiana J, Bosch Tyler A, Bush Foster K, Chow Lisa S, Dengel Donald R
1Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, MN; 2College of Education and Human Development, University of Minnesota, Minneapolis, MN; 3Department of Medicine, University of Minnesota Medical School, University of Minnesota, Minneapolis, MN; and 4Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN.
Med Sci Sports Exerc. 2017 Apr;49(4):833-839. doi: 10.1249/MSS.0000000000001168.
This study aimed to investigate the accuracy and reliability of a novel dual-energy x-ray absorptiometry (DXA) scanning method in the frontal plane for total, fat, and lean mass quantification of the anterior and posterior upper leg compartments.
Twenty-one (11 females; X¯age = 20.3 ± 1.3 yr) college athletes were assessed for total and regional body composition using DXA. The segmentation of anterior/posterior thigh compartments was measured with participants lying on their right and left sides and the scanned leg elevated with two foam pads. Custom regions of interest (ROIs) were created manually with enCore software for each scan using bony landmarks to quantify lean, fat, and total masses. Paired t-tests assessed this novel positioning method's accuracy against standard positioning. Intraclass correlation coefficients and coefficients of variation examined inter- and intrarater reliability for lateral scan measures of total, fat, and lean masses from manually created ROIs.
All mean ± SD differences between frontal and lateral DXA scans of right (R) and left (L) leg total mass (R: 8.42 ± 195.57 g; L: 19.47 ± 131.80 g), fat mass (R: 61.26 ± 215.66 g; L: -5.89 ± 239.97 g), and lean mass (R: -103.00 ± 302.54 g; L: -27.58 ± 288.14 g) were nonsignificant (P value range = 0.15-0.91). Intraclass correlation coefficients were high for all composition measures between and within raters, ranging from 0.983 to 0.999 and from 0.954 to 0.999, respectively, with low variation across measures (all coefficients of variation ≤ 5%).
The results of this study suggest that DXA measures using lateral subject positioning and custom ROIs to assess upper leg total, fat, and lean masses are accurate and reliable compared with total-body frontal subject positioning. Future studies are needed to determine the clinical usefulness of lateral view measures regarding prevention or rehabilitation of sports- or age-related injury.
本研究旨在调查一种新型双能X线吸收法（DXA）扫描方法在额面用于定量大腿前后部总质量、脂肪质量和瘦体重的准确性和可靠性。
使用DXA对21名（11名女性；平均年龄=20.3±1.3岁）大学运动员的全身和局部身体成分进行评估。让参与者分别侧卧，用两个泡沫垫抬高扫描侧的腿，测量大腿前后部的分割情况。使用enCore软件，根据骨标志手动为每次扫描创建自定义感兴趣区域（ROI），以量化瘦体重、脂肪质量和总质量。配对t检验评估这种新定位方法相对于标准定位的准确性。组内相关系数和变异系数检验了手动创建ROI的总质量、脂肪质量和瘦体重横向扫描测量的评分者间和评分者内可靠性。
右（R）腿和左（L）腿总质量（R：8.42±195.57克；L：19.47±131.80克）、脂肪质量（R：61.26±215.66克；L：-5.89±239.97克）和瘦体重（R：-103.00±302.54克；L：-27.58±288.14克）的额面和侧面DXA扫描的所有均值±标准差差异均无统计学意义（P值范围=0.15 - 0.91）。评分者间和评分者内所有成分测量的组内相关系数都很高，分别为0.983至0.999和0.954至0.999，各测量的变异系数较低（所有变异系数≤5%）。
本研究结果表明，与全身额面受检者定位相比，使用侧面受检者定位和自定义ROI的DXA测量来评估大腿总质量、脂肪质量和瘦体重是准确且可靠的。未来需要开展研究以确定侧面视图测量在预防或康复运动相关或年龄相关损伤方面的临床实用性。
