Ultrasound physical principles in today's technology.

: New technology options are being provided on modern ultrasound machines such as tissue harmonic imaging, panoramic imaging, encoded pulses, mechanical and matrix 4D ultrasound and elastography. The increase in available features requires enhanced knowledge of the clinical benefits associated with each feature and of the additional diagnostic information in the images. However the question arises as to the necessity of understanding how these new technologies work. Also, ultrasound machines have become much more automated in recent years, with designers making it easier for users to produce excellent quality images with minimal technical input. : System presets provide adjustments to a variety of basic settings without the user requiring the knowledge of what each setting is doing. The developments in machine design and the increased level of automation pose an interesting question for sonologists and sonographers: Is there a need to know as much about the physical principles of ultrasound today as was required in the past? : To answer this question, this article will look at just one recent advance in ultrasound - Tissue Harmonic Imaging. The various mechanisms of this technology will be discussed with reference to the underlying principles of basic ultrasound physics. The conclusion provided is that a good grounding in the physics of ultrasound remains of vital importance in understanding new technologies and enabling informed decisions to be made on their use.