8. Barriers to the use of multi-elements

8.1 Physical limits

As with conventional ultrasound techniques, multi-elements face the same physical limitations:

• the translator's aperture is decisive in determining the limit of the Fresnel zone, for both multi-element and single-element applications: it will not be possible to focus beyond it;

• the attenuation or noise of a material is a constraint, and the choice of a multi-element transducer is the result of a compromise, as with a single-element transducer. The multi-element technique can only be used to improve resolution or signal-to-noise ratio in very specific cases (see...