ABSTRACT

The formation of ultrasound images of internal anatomy involves a wide range of physical processes. These include the generation of ultrasound waves, the formation of ultrasound beams, reflection, scattering, diffraction and attenuation of ultrasound waves and the processing of echoes to create a recognisable image. The Mexican wave is a simple example that demonstrates an important aspect of waves. The person at one end of a long line of people raises his or her arms briefly. As the arms of the first person are lowered, the next person in the line performs the same action. Radio waves and light waves are electromagnetic waves. They can travel not only through some solids, liquids and gasses, but also through the vacuum of space. The waves that we are concerned with in this text are mechanical waves, which travel through a deformable or elastic medium such as a solid or liquid. Waves may be classed as transverse or longitudinal waves.