Fig. 3.

(a) Simulated temperature increases in the axial-lateral plane (centered in elevation) for a single ARFI interrogation using a relatively high frequency (7 MHz), and tight focal configuration (F/1.3). The transducer is centered along the top of the image, spanning a total of 1.52 cm laterally. The focus is at 2.0 cm. (b) Temperature increases after a single frame of two-dimensional ARFI imaging using the pulse from (a) in a high contrast beam sequence (50 tightly focused, closely spaced (0.35 mm) push pulses, with a time delay of 5 ms between successive locations temporally), assuming a tissue. absorption of 0.5 dB/cm/MHz. Note that the maximum temperature increase has shifted from the focal depth of 2.0 cm (the location of maximum temperature increase for a single ARFI interrogation), to 1.45 cm, which is the region of maximum overlap for the sequence. (c) Real-time, two-dimensional ARFI imaging, using the same sequence as in (b), performed at a frame rate of 3 frames per second for a total duration of 3 seconds. Note that the temperature scale, in degrees Celsius, is different for each figure. Figure reproduced with permission from:(43)