Answer #43

The correct answer is B: penetration is worse compared to fundamental imaging.

Harmonic imaging means transmitting at a fundamental frequency and receiving signals at some multiple of that fundamental frequency, usually at the 2nd harmonic which corresponds to twice the fundamental frequency. The harmonic response is non linear with increasing intensity and varies significantly with imaging depth. The main advantage of harmonic imaging is to decrease clutter signals and also imaging artifacts. Ideally there should be little overlap between the fundamental (trasmitting) and harmonic (receiving) bandwidths so that the quality of the harmonic image is not degraded.
Because the harmonic frequency is by definition higher than the fundamental frequency and because at greater imaging depths, there is increased rate of attenuation for hamornic signals, penetration is worse with harmonic imaging.