Basics of Ultrasound: Pitfalls and Limitations

Abstract

Ultrasound has been used to image the human body for over half a century. Dr. Karl Theo Dussik, an Austrian neurologist, was the first to apply ultrasound as a medical diagnostic tool to image the brain [1]. Today, ultrasound (US) is one of the most widely used imaging technologies in medicine. It is portable, free of radiation risk, and relatively inexpensive when compared with other imaging modalities, such as magnetic resonance and computed tomography. Furthermore, US images are tomographic, i.e., offering a “cross-sectional” view of anatomical structures. The images can be acquired in “real time, " thus providing instantaneous visual guidance for many interventional procedures including those for regional anesthesia and pain management. In this chapter, we describe some of the fundamental principles and physics underlying US technology that are relevant to the pain practitioner.