4829 MR Endoscopy vs EUS : A Comparison

Introduction Endoscopic ultrasound (EUS) is a well-established, safe modality for real-time imaging of the duodenum and nearby ductal systems. However, all echo-ranging imaging suffers from artifacts, the most significant being reverberation between impedance discontinuities. As a result, concentric artifacts dominate the near field even when a balloon is used. Acoustic shadowing is caused by strongly reflecting structures (voids such as lungs and bowel; bone and gallstones), while enhancement is caused by weakly attenuating fluid-filled structures (bladder and cysts). These artifacts cannot be suppressed without eliminating the fundamental contrast mechanism, unless a nonlinear contrast agent is used. As a result, EUS images are patient and operator dependent, and often hard to interpret. Although slower, internal MRI may therefore offer advantages, and suitable gastroscopes have already been developed. The aim of this paper is to compare the performance of a new MR-imaging duodenoscope with EUS.