Figure 2.

The real-time tissue elastographic (RTE) image (left image) and the B-mode image (right image) for the measurement of the levator scapulae. The color code indicates the relative strain of the tissues, ranging from red (soft) to blue (hard). The region of interests (ROIs), which is represented as yellow rectangle, were individually set on the acoustic coupler (A) and the muscle (B). The depth of the ROIs was defined as approximately the middle two-thirds of the acoustic coupler and the muscle to avoid the boundary condition effect. The width of the ROI on the muscle was adjusted to coincide with that on the acoustic coupler. The strain ratio (B/A) was automatically calculated from the strains of the acoustic coupler (A) and the muscle (B) in the ROIs. C, coupler; U, the upper trapezius; L, the levator scapulae.