Basic Science: Principles of Ultrasound: Obtaining an Image, Resolution, Depth, Frequency, Resonance

Abstract

Ultrasound has become an essential tool for the modern anesthesiologist. Its value has been demonstrated in establishing vascular access, performing regional anesthetic techniques, and perioperative patient evaluation through the use of Point of Care Ultrasound. However, the ability to use ultrasound effectively in clinical practice requires a facile understanding of the principles that underlie this imaging modality. An understanding of the principles of frequency’s effect on resolution is important in selecting an appropriate ultrasound probe. An understanding of the way that ultrasound waves travel in biologic tissues is important for obtaining a high-quality ultrasound image. An understanding of the causes of ultrasound artifacts is important in interpreting those images. Additionally, it is important to understand how ultrasound machines interpret the ultrasonic signals that they receive. Through a basic understanding of the various modes which exist in modern ultrasound machines, one can take full advantage of this important imaging modality.