Ultrasound Basics

The use of ultrasound guidance is increasingly popular for interventional pain management and has been demonstrated to be superior to landmark based injections. Proper knowledge of the mechanisms by which this technology works is essential for the success of ultrasound-guided procedures and allows for the maximum utility this technology offers. There are different types of probes depending on the objective that is required, the higher the frequency, the more the attenuation; lower frequency probes (2–5 MHz) are used to visualize deeper structures, higher frequency probes (5–18 MHz) are most often used for superficial structures. Regarding the procedures, there is nomenclature that describes the ultrasound probe-to-target orientation and the probe-to-needle disposition. The position and comfort of the doctor are very important when performing a procedure. Ultrasound is a tool that helps us to identify the target with the surrounding tissues, being able to observe the soft tissue and vascular structures which cannot be identified when procedures are performed with fluoroscopy. This chapter will discuss the fundamentals of ultrasound science and technology for the interventional pain physician.