There are 3 possibilities when an ultrasound wave enters tissue: Transmission Attenuation Reflection Wave and its energy pass through the tissue in its propagation direction Wave loses energy due to interaction with tissue Wave changes direction and travels back...
The transducer alternates through phases of generating and receiving ultrasound waves The ‘Transmission Phase’ is the period of wave generation: Usually very brief (0.5–3 μs) Followed by a ‘Receiver Phase’ for wave detection: Much longer (up to...
Ultrasound waves are produced by an ultrasound probe: An electric current is passed through a piezoelectric crystal: Act as transducers converting electrical energy into mechanical vibrations at high frequencies Generates ultrasound waves at the frequency of the...
An effect exhibited by certain quartz crystals (such as lead zirconate titanates) known as ‘piezoelectric crystals’: Also exhibited by certain ceramics and biological materials such as collagen and DNA The piezoelectric crystal will change shape when an...
Attribute Intensity Definition The power of a wave present per unit area Unit W/m2 SI Unit kg/s3 Intensity varies throughout a diagnostic ultrasound beam It is highest at the centre of the beam, tapering off at the periphery It also varies along the path of the beam...
