Comparison of image quality between electronic and mechanical radial scanning echoendoscopes in pancreatic diseases

Background and Aim: It is common knowledge that endoscopic ultrasonography (EUS) can accurately diagnose pancreatic diseases. Echoendoscopes for EUS are roughly classified into two categories, the mechanical radial scanning echoendoscope (MR-ES) and the electronic linear array echoendoscope, both of which have their merits and demerits. In 2000, a newly designed echoendoscope, the electronic radial scanning echoendoscope (ER-ES), appeared. The aim of the present study was to compare B-mode image quality between the ER-ES and the MR-ES in pancreatic diseases. Methods: Patients with pancreatic diseases (30 cystic diseases and 22 solid diseases) underwent EUS with both ER-ES and MR-ES. The B-mode images obtained using both echoendoscopes were graded using a scoring system and statistically analyzed. The assessed point for cystic lesions was the existence of mechanical-noise-like ring-like artifacts derived using multiple reflections ('ring-down'), grating robe and so on, and that for solid lesions was the scale of penetration. The authors compared maneuverability, endurance and endoscopic images between the two types of echoendoscopes. Results: The ER-ES had a significantly higher score than the MR-ES (P < 0.05) in the analysis of both cystic and solid diseases. There was no apparent difference as to maneuverability, endurance and endoscopic images. Conclusion: Ultrasound images acquired by ER-ES appear better compared with those acquired by MR-ES.