Figure 3.

Sequence of 1100 MHz conductivity difference images at time points (in seconds from the start of the first microwave image acquisition) during and after heating (US power was turned on at 143 seconds and off at 1420 seconds) from the beam steering pattern shown in Figure 2: (A) 143, (B) 321, (C) 499, (D) 678, (E) 856, (F) 1034, (G) 1213, (H) 1391, (I) 1569, (J) 1748, (K) 1926, and (L) 2105 seconds, respectively. Difference images were formed by subtracting the pre-heating baseline conductivity image from the conductivity image acquired at the time points indicated.