Combining low echo reduction and gain adjustment for enhanced pancreatic visualization in endoscopic ultrasound

Article information

Clin Endosc. 2025;.ce.2024.358

Publication date (electronic) : 2025 April 24

doi : https://doi.org/10.5946/ce.2024.358

Akashi Fujita, Masafumi Mizuide, Shomei Ryozawa, Yuki Tanisaka, Ryuhei Jinushi, Ryuichi Watanabe

Department of Gastroenterology, Saitama Medical University International Medical Center, Saitama, Japan

Correspondence: Masafumi Mizuide Department of Gastroenterology, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan E-mail: mizuide1971@yahoo.co.jp

Received 2024 December 30; Revised 2025 March 3; Accepted 2025 March 12.

Endoscopic ultrasound (EUS) is a widely used imaging modality that provides high-resolution visualization for pancreatic evaluation.1,2 A novel ultrasound observation system (EVIS EUS-EU-ME3; Olympus) that incorporates a low echo reduction (LER) function to enhance contrast between high- and low echo areas was developed. The utility of this innovative function in pancreatic imaging has been extensively reported.3 However, when adjusted alone, LER can excessively darken the image, making accurate evaluation challenging. This function typically has a default level of 3, adjustable from 1 to 20. Combining LER with gain adjustment mitigates these limitations, enabling a more detailed and balanced visualization of pancreatic structures.

A 72-year-old woman was referred to our hospital for evaluation of pancreatic duct dilatation detected on imaging. Computed tomography and magnetic resonance cholangiopancreatography did not reveal a clear pancreatic mass but showed dilation of the distal pancreatic duct. EUS was performed using a linear array endoscope (UCT260; Olympus) to investigate potential malignancy (Video 1). Initial settings included an LER value of 3 and a gain of 10. Increasing the LER to 14 significantly enhanced contrast but excessively darkened the image, reducing clarity. Adjusting the gain to 15 successfully balanced brightness and contrast, improving visualization of both the pancreatic parenchyma and duct. This detailed assessment revealed branch duct dilation but no evidence of a malignant mass (Fig. 1). Based on these findings, the patient was diagnosed with a branch-duct intraductal papillary mucinous neoplasm and a pancreatic cystic lesion.

Fig. 1.

Comparison of pancreatic parenchyma and branch duct visualization before and after low echo reduction (LER) and gain adjustment. (A) Initial settings: LER set to 3 and gain to 10, providing standard visualization of the pancreatic parenchyma. (B) Adjusted settings: LER set to 14 and gain to 15, with enhanced contrast and brightness, improving the evaluation of the pancreatic parenchymal structure. (C) Initial settings: LER set to 3 and gain to 10, providing standard visualization of the dilated branch pancreatic duct. (D) Adjusted settings: LER set to 14 and gain to 15, achieving enhanced contrast and clarity, enabling a detailed evaluation of the dilated branch duct.

This case highlights the importance of combining LER and gain adjustments to optimize EUS imaging quality. Such adjustments enhance visualization and improve diagnostic accuracy for pancreatic lesions, and may also have broader applications in EUS-guided tissue acquisition and pancreatic duct drainage, where precise and reliable imaging is essential.

The patient involved in this study provided informed consent for the use of her clinical information and imaging. This study was conducted in accordance with the principles outlined in the Declaration of Helsinki.