Outcomes
The maximal horizontal displacement (mm) of SM and GM was quantified using cross-correlation analysis of the recorded US videos. The used MATLAB—(The MathWorks, Inc., Natick, MA, United States) based algorithm uses pre-defined determined regions of interest (ROI) to determine the correlation coefficients between pixel grey levels of successive framesTo analyze the tissue displacement of the SM, six equidistant ROIs (approximate size: 5 × 1 mm) were selected in the middle of the US imageExemplary visualization of the ultrasound cross-correlation analysis in (