Figure 4.

Axial free-hand strain elastograms of (a) normal relaxed calf muscles and (b) vastus lateralis muscle. The medial and lateral heads of gastrocnemius (M and L, respectively), as well as the vastus lateralis (VL), appear as a mosaic of intermediate or increased stiffness (green or blue colour, respectively), with scattered softer (red) areas near muscle boundaries. The subcutaneous fat appears soft (red/yellow). The homogeneous stiff appearance of soleus (S) in (a) is probably because of inadequate B-mode and ultrasound elastography data due to increased depth.