Purpose of review
Real-time two-dimensional ultrasound guidance is undoubtedly one of the most important evolutions in the field of regional anesthesia techniques, for peripheral nerve blocks and neuraxial anesthesia. The recent literature has been analyzed for studies concerning new technological trends in ultrasound-guided regional anesthesia. This review focuses on electromagnetic tracking systems for ultrasound guidance and three/four-dimensional ultrasound imaging in regional anesthesia.
Electromagnetic tracking can facilitate needle-beam alignment for in-plane approaches and indicates where the needle crosses the beam during out-of-plane ultrasound-guided procedures. Three-dimensional ultrasound imaging can provide more detailed anatomical information and better spatial orientation than two-dimensional imaging. Four-dimensional ultrasound imaging enhances the visualization of a particular anatomy and offers real-time assessment of local anesthetic spread during ultrasound-guided regional anesthesia. These techniques have some limitations and drawbacks limiting their expansion.
This article describes the principles, technology and development of electromagnetic tracking system for ultrasound guidance and three/four-dimensional ultrasound imaging in regional anesthesia, considering whether these new technologies will have impending applications in clinical practice.