Figure 3.

SNR variations for numerical TM phantoms with variations in the backscatter intensity from −3 to 3 dB with respect to the backscatter level of the reference phantom. The sound speeds in the phantoms were 1540 m/s. The sample phantom attenuation coefficients were (a) 0.5, (b) 0.3, (c) 0.7 dB/cm/MHz. In all cases, the reference phantom had a 0.5 dB/cm/MHz attenuation coefficient, 50 μm scatterer diameter, and 1540 m/s sound speed at a scatterer density of 20 scatterers/mm³. The frequency range was 2–9 MHz.