Dankel Scott J, Abe Takashi, Bell Zachary W, Jessee Matthew B, Buckner Samuel L, Mattocks Kevin T, Mouser J Grant, Loenneke Jeremy P
Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, University, MS, USA.
School of Kinesiology, University of Southern Mississippi, Hattiesburg, MS, USA.
J Clin Densitom. 2020 Oct-Dec;23(4):630-638. doi: 10.1016/j.jocd.2018.10.003. Epub 2018 Oct 25.
INTRODUCTION/BACKGROUND: To determine the influence of ultrasound probe tilt on reliability and overall changes in muscle thickness and echo-intensity.
Thirty-six individuals had a total of 15 images taken on both the biceps brachii and tibialis anterior muscles. These images were taken in 2° increments with the probe tilted either upward (U) or downward (D) from perpendicular (0°) to the muscle (U6°, U4°, U2°, 0°, D2°, D4°, and D6°). All images were then saved, stored, and analyzed using Image-J software for echo-intensity and muscle thickness measures. Mean values (2-3 measurements within each probe angle) were compared across each probe angle, and reliability was assessed as if the first measure was taken perpendicular to the muscle, but the second measure was taken with the probe tilted to a different angle (to assume unintentional adjustments in reliability from probe tilt).
Tilting the probe as little as 2° produced a significant 4.7%, and 10.5% decrease in echo-intensity of the tibialis anterior and biceps brachii muscles, respectively, while changes in muscle thickness were negligible (<1%) at all probe angles. The reliability for muscle thickness was greater than that of echo-intensity when the probe was held perpendicular at both measurements (∼1% vs 3%), and the impact that probe tilt had on reliability was exacerbated for echo-intensity measurements (max coefficient of variation: 24.5%) compared to muscle thickness (max coefficient of variation: 1.5%).
While muscle thickness is less sensitive to ultrasound probe tilt, caution should be taken to ensure minimal probe tilt is present when taking echo-intensity measurements as this will alter mean values and reduce reliability. Echo-intensity values should be interpreted cautiously, particularly when comparing values across technicians/studies where greater alterations in probe tilt is likely.
引言/背景：确定超声探头倾斜对肌肉厚度和回声强度的可靠性及总体变化的影响。
36名个体的肱二头肌和胫骨前肌共采集了15张图像。这些图像以2°的增量拍摄，探头从垂直于肌肉的方向（0°）向上（U）或向下（D）倾斜（U6°、U4°、U2°、0°、D2°、D4°和D6°）。然后使用Image-J软件保存、存储并分析所有图像，以测量回声强度和肌肉厚度。比较每个探头角度的平均值（每个探头角度内进行2 - 3次测量），并评估可靠性，假设第一次测量时探头垂直于肌肉，但第二次测量时探头倾斜到不同角度（以假定探头倾斜对可靠性产生无意的调整）。
探头倾斜仅2°时，胫骨前肌和肱二头肌的回声强度分别显著降低4.7%和10.5%，而在所有探头角度下肌肉厚度的变化可忽略不计（<1%）。当两次测量时探头均保持垂直时，肌肉厚度的可靠性高于回声强度（约1%对3%），与肌肉厚度（最大变异系数：1.5%）相比，探头倾斜对回声强度测量可靠性的影响更为严重（最大变异系数：24.5%）。
虽然肌肉厚度对超声探头倾斜不太敏感，但在进行回声强度测量时应谨慎确保探头倾斜最小，因为这会改变平均值并降低可靠性。应谨慎解释回声强度值，特别是在比较不同技术人员/研究的值时，此时探头倾斜的变化可能更大。
