Radial Endoscopic Ultrasound

Abstract

Over the past decade, radial endoscopic ultrasonography has emerged as a powerful diagnostic tool for evaluating and staging neoplasms of the gastrointestinal tract. Although the initial radial echoendoscopes were heavy, cumbersome instruments, technological advances have resulted in slimmer, lighter scopes with increased agility and a wider range of ultrasound frequencies. Initially, this technology was limited to large, tertiary referral centers due to excessive equipment costs and lack of skilled endosonographers. However, the ever increasing demand for EUS has led to investment in both equipment and experienced endosonographers by some smaller community programs and private practitioners. For the beginner, understanding the basic principles of radial EUS is fundamental for establishing the skill set necessary to perform an accurate and efficient exam. A systematic approach to each anatomical station of the digestive tract is critical for assuring a thorough and complete exam. Review of both anatomical and radiologic atlases is helpful for the beginner to understand and accurately interpret ultrasound images. This chapter focuses on the technical details of performing radial EUS on the upper gastrointestinal tract and rectum. Furthermore, attention is directed toward the recognition of common anatomical landmarks in efforts to improve both the efficiency and accuracy of the exam. Although reading a textbook chapter obviously does not substitute for dedicated, supervised hands-on training, a general understanding of the procedure and common anatomical landmarks is crucial to begin EUS training.