Fabian Kraus, Stephan Hackenberg, Wafaa Shehata-Dieler, Rudolf Hagen

• Purpose Flexible endoscopic evaluation of swallowing (FEES\(^{®}\)) is a standard diagnostic tool in dysphagia. The combination of FEES® and narrow band light (narrow band imaging; NBI) provides a more precise and detailed investigation method. So far, this technique could only be performed with the NBI illumination. The new version of the "professional image enhancement technique" (PIET) provides another image enhancing system. This study investigates the eligibility of PIET in the FEES\(^{®}\) procedure. Methods Both techniques, NBI andPurpose Flexible endoscopic evaluation of swallowing (FEES\(^{®}\)) is a standard diagnostic tool in dysphagia. The combination of FEES® and narrow band light (narrow band imaging; NBI) provides a more precise and detailed investigation method. So far, this technique could only be performed with the NBI illumination. The new version of the "professional image enhancement technique" (PIET) provides another image enhancing system. This study investigates the eligibility of PIET in the FEES\(^{®}\) procedure. Methods Both techniques, NBI and PIET, were compared using a target system. Furthermore, the image enhancement during FEES\(^{®}\) was performed and recorded with the two systems during daily routine. Results Performing an image enhancement during FEES\(^{®}\) is possible with both systems PIET and NBI. On the target system, the contrast of the PIET showed a brighter and a more detailed picture. In dysphagia patients, no difference between PIET and NBI was detected. Conclusion PIET proved to be non-inferior to NBI during image enhancement FEES\(^{®}\). So far, image enhancement FEES\(^{®}\) was exclusively connected to NBI. With the PIET system, an alternative endoscopy technology is available for certain indications.…