Quantification of collagen fiber orientation in human tendons with the coefficient of variation of echogenicity
Quantification of collagen fiber orientation in human tendons with the coefficient of variation of echogenicity
复制标题
用回声变异系数量化人体肌腱中的胶原纤维取向
DOI：
10.1016/j.jbiomech.2016.11.004
复制
发表时间：
2016
影响因子：
2.4
通讯作者：
Kubo K.
中科院分区：
文献类型：
--
作者：
Ishigaki T;Kouno M;Ikebukuro T;Kubo K.
肌腱超声图像上的灰度分布可能随着胶原纤维的排列而降低，这是由于肌腱的声学各向异性导致肌腱胶原纤维取向的改变而导致超声信号强度的变化。本研究的目的是探讨被动背屈（角度任务）和等距足底屈（收缩任务）时跟腱回声变异系数（CV）的变化。在角度任务中，从20°到- 20°每10°（足底屈曲阳性值）采集14名健康人的跟腱横向超声图像，在收缩任务中，从0%到70% MVC每10%最大自愿收缩（MVC）采集一次。测量每幅图像的回声度CV。此外，比较了各任务前半部分（角度20°~ 0°，收缩任务MVC比例为0% ~ 30%）和后半部分（角度0°~ - 20°，收缩任务MVC比例为40% ~ 70%）测量变量的相对变化。回声强度随背屈角度和收缩强度的增大而减小。此外，在角度任务中，背屈程度越高，在收缩任务中，背屈程度越低，回声度CV的相对变化越大。这些结果表明，回声性CV的降低部分与肌腱拉伸时肌腱胶原纤维的排列有关。
The grayscale distribution on the ultrasonic images of tendons may be reduced with alignment of collagen fibers, because ultrasound signal intensity changes with alterations in tendon collagen fiber orientation due to acoustic anisotropy in the tendons. The purpose of this study was to investigate changes in the coefficient of variation (CV) of echogenicity in the Achilles tendon during passive dorsiflexion (the angle task) and isometric plantar flexion (the contraction task). Achilles tendon transverse ultrasonic images were collected from 14 healthy individuals every 10° from 20° to −20° (positive values for plantar flexion) in the angle task and every 10% maximum voluntary contraction (MVC) from 0% to 70% MVC in the contraction task. The CV of echogenicity was measured in each image. In addition, relative changes in the measured variables between the former half (20–0° in the angle task, 0% to 30% MVC in the contraction task) and the latter half (0° to −20° in the angle task, 40% to 70% MVC in the contraction task) of each task were compared. The CV of echogenicity decreased with increases in the dorsiflexion angle and intensity of isometric contractions. Furthermore, relative changes in the CV of echogenicity were greater at more dorsiflexed positions in the angle task and at lower torque levels in the contraction task. These results suggested that decreases in the CV of echogenicity were partially related to the alignment of the tendon collagen fibers with tendon stretching.