Basic Physics and Imaging Characteristics of Ultrasound |
| |
Authors: | George Kossoff |
| |
Institution: | (1) 1 Bowes Avenue, Killara, New South Wales 2071, Australia, AU |
| |
Abstract: | The imaging characteristics of diagnostic ultrasound (US) are determined by the ultrasonic properties of tissue. The velocity
of propagation of US and the attenuation are the 2 most important parameters. These determine the frequency with which the
tissues may be imaged, which in turn sets a fundamental limit on the axial and the lateral resolution. Ultrasonic imaging
equipment is designed on the premise that the ultrasonic energy propagates through tissue in a straight line and that the
ultrasonic beam is very narrow. In fact, the ultrasonic energy propagates through tissue as a beam of finite dimensions set
by the physical dimensions of the transducer, the way it is constructed, and the way it is energized. Also, the velocity of
propagation in different tissues varies and this can lead to deviation of the ultrasonic beam from the assumed direction of
propagation. This breakdown in assumptions leads to the creation of artifacts that must be appreciated in the interpretation
of ultrasonic images. For this reason skilled interpreters of ultrasonic images follow 3 golden rules: never make an interpretation
on a single image; just because a feature is displayed do not consider that it is necessarily real; and just because a feature
is not displayed do not consider that it is necessarily not there. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|