Yang Long, Yuan Jianjun, Wang Qi, Wu Gang, Guo Wen-Qing, Wang Wen-Wei, Zhao Bing
Department of Ultrasound, The People's Hospital of Zhengzhou University (Henan Provincial People's Hospital), Zhengzhou, China.
Ultrasound Q. 2015 Mar;31(1):59-62. doi: 10.1097/RUQ.0000000000000070.
The effect of scanning angle and region of interest (ROI) depth on shear-wave velocity (SWV) was investigated in this study. Shear-wave velocity of ox liver ex vivo was measured with different approaches. Region of interest was set underneath the liver capsule at depths of 1, 2, 3, 4, and 5 cm. Three groups of measurements were performed at different scanning angles. One group of measurement was conducted with a scanning angle of 0 to 15 degrees from the midline, and the other 2 groups were performed with scanning angles of 15 to 30 degrees and 30 to 45 degrees. The data on SWV from different scan angles and ROI depths were analyzed statistically. Scanning angle and ROI depth were found to be the 2 factors that affect SWV. Interaction was observed between the scan angle and ROI depth. The data at different depths within 0- to 15-degree scanning angles exhibited no significant difference. However, the reliability of SWV decreased with the increase in ROI depth. In the groups of 15 to 30 degrees and 30 to 45 degrees, a significant difference was found between the 2 different measured depths. Scanning angle and ROI depth affected the reliability of SWV measurement. The scanning angle should be confined within 15 degrees from the midline. Therefore, SWV from shallow ROI is more reliable than that at deep ROI.
本研究探讨了扫描角度和感兴趣区域（ROI）深度对剪切波速度（SWV）的影响。采用不同方法测量了离体牛肝的剪切波速度。感兴趣区域设置在肝包膜下方1、2、3、4和5厘米深度处。在不同扫描角度下进行了三组测量。一组测量是在与中线成0至15度的扫描角度下进行的，另外两组是在15至30度和30至45度的扫描角度下进行的。对不同扫描角度和ROI深度的SWV数据进行了统计分析。发现扫描角度和ROI深度是影响SWV的两个因素。观察到扫描角度和ROI深度之间存在相互作用。在0至15度扫描角度内不同深度的数据无显著差异。然而，SWV的可靠性随ROI深度的增加而降低。在15至30度和30至45度的组中，发现两个不同测量深度之间存在显著差异。扫描角度和ROI深度影响SWV测量的可靠性。扫描角度应限制在距中线15度以内。因此，浅ROI的SWV比深ROI的更可靠。
