It is important to note that sound waves brought into use in modern day ultrasound applications are based on highly complex acoustic structures and that this complexity of structured is further increased when the sound waves are propagated to pass through complex tissue structures. In terms of their physics, the spatial resolution of the ultrasound acoustic waves is maintained at a length that spans less than a singular millimeter. The velocity may lie anywhere between 1450m/s to 1600m/s and the wavelength may be present in anywhere between 0.15mm to as far as 0.75mm (Hofer, 1999).
Symmetry of the sound waves transmitted is of the utmost importance in the application of ultrasound and modern day ultrasound machines bring phased arrays into use in order to ensure symmetry. Also, any discussion on ultrasound, its applications and its implications will be incomplete without an overview of the properties of tissues that make them responsive to ultrasound. Ultrasound images are generally formed as a result of the impedance, scattering, attenuation and absorption of sound waves. Tissues generally tend to emit a plane sound wave as a result of absorption and scattering phenomena.