Ultrasound Physics & Overview

Abstract

This chapter reviews the basic physics principles of ultrasound waveforms as well their interaction with soft tissues. Key concepts include reflection, attenuation, acoustic impedance and their effects on image formation, Doppler angle as well as Doppler shift and the utility of ultrasound in vascular imaging. In addition, ultrasound instrumentation is reviewed. This includes the function of transducers and their piezoelectric components, common types of transducers and standard placement orientations on the body surface. The physics of ultrasound image generation is also discussed, including conventional gray-scale imaging as well as Doppler ultrasound imaging. Lastly, a review of common artifacts seen on ultrasound imaging and the physics resulting in artifact formation, some of which can be of diagnostic aid when trying to evaluate for pathology, will be discussed.