Objective Evaluation of a New Endoscopic Ultrasound (EUS) Processor

Abstract

Purpose: Image quality is critical for EUS examinations. High-end EUS processors have advanced features, but are expensive, space-consuming and not easily portable. Smaller-sized processors are more economical and portable, but have fewer features and are limited by image quality. A new EUS processor has recently been developed with the objective of being more versatile in functionality, portable and able to generate high-quality imaging. Aim: To evaluate the technical performance of a newly developed EUS processor. Methods: EUS processor EU-Y0006 (Olympus Medical Systems Corp.) is a compact, portable system with a touch screen keyboard. The processor has Tissue Harmonic Echo capability with penetration (THE-P) and resolution (THE-R) modes, pulse wave doppler and high-resolution flow mode. Study design: This is a prospective, single-blind study that compared the performance of the new EU-Y0006 processor with a commercially available high-end processor (ProSound Alpha 10, Hitachi Aloka Medical Ltd.). Visiting (observer) endosonographers (experience >150 procedures) were instructed to observe and grade image quality generated by both processors in individual patients. The top borders of image monitors were masked so as to blind the observer to source generator. Examinations were initiated in random sequence with either processor. Without withdrawing the echoendoscope, the generators were changed and the examination was continued. Given the predefined criteria and clinical importance, only pancreatic exams were included: suspected chronic pancreatitis (CP), solid pancreatic masses (SPM) and pancreatic cysts (PC). The overall image quality was graded 0-5 and morphological features of disease states were compared in individual patients. Results: Forty three observations were performed on 24 patients: CP (n=10), SPM (n=6) and PC (n=8). There was no significant difference in the median score for overall image quality in PC (5 vs. 5; p=0.63) and SPM (5 vs. 5; p=0.66), or for total number of EUS criteria (n=9) in CP (3 vs. 3; p=0.99) between Alpha 10 and EU-Y0006 processors, respectively. No significant difference in vascular or nodal involvement, metastasis or ascites (p=0.99) and cyst morphology (p>0.05) was observed between both processors. Although statistically insignificant, cyst-duct communication (0 vs. 21.4%; p=0.22) and septations (14.3 vs. 35.7%; p=0.39) were observed more definitively with EU-Y0006. Conclusion: Technical performance of the new EUS processor was comparable to that of the currently available high-end EUS processors. This development has implications for decreasing EUS capital equipment costs and for further dissemination of EUS technology. Disclosure - Dr. Shyam Varadarajulu - Consultant for Olympus Corp. and Boston Scientific, involved with teaching, research and development Dr. Robert Hawes - Consultant for Olympus Corp. and Boston Scientific, involved with teaching, research and development