The solid lines in (a,d,g) represent the FEM displacement data, centered laterally, 0.2, 1.2, and 2.0 ms after ARFI excitation, respectively, as was shown in Fig. 2(a,d,g). The dashed line represents the tracked displacement data along these center lines. The dashed lines in (b,e,h) represent the same tracked data as in (a,d,g), while the solid line represents the tracked data after a 3.85 mm kernel running average. The plots in (c,f,i) represent the jitter in the tracked displacement data after the running average data (solid lines) were subtracted from the raw tracked data (dashed lines) in (b,e,h). Note that the underestimation of maximum displacement is worse in the early time step (a), and the focal zone jitter is worse immediately after excitation (c) than later in time (f,i).