Recent advancements in image-enhanced endoscopy in the pancreatobiliary field

Abstract

Image-enhanced endoscopy (IEE) has advanced gastrointestinal disease diagnosis and treatment. Traditional white-light imaging has limitations in detecting all gastrointestinal diseases, prompting the development of IEE. In this review, we explore the utility of IEE, including texture and color enhancement imaging and red dichromatic imaging, in pancreatobiliary (PB) diseases. IEE includes methods such as chromoendoscopy, optical-digital, and digital methods. Chromoendoscopy, using dyes such as indigo carmine, aids in delineating lesions and structures, including pancreato-/cholangio-jejunal anastomoses. Optical-digital methods such as narrow-band imaging enhance mucosal details and vessel patterns, aiding in ampullary tumor evaluation and peroral cholangioscopy. Moreover, red dichromatic imaging with its specific color allocation, improves the visibility of thick blood vessels in deeper tissues and enhances bleeding points with different colors and see-through effects, proving beneficial in managing bleeding complications post-endoscopic sphincterotomy. Color enhancement imaging, a novel digital method, enhances tissue texture, brightness, and color, improving visualization of PB structures, such as PB orifices, anastomotic sites, ampullary tumors, and intraductal PB lesions. Advancements in IEE hold substantial potential in improving the accuracy of PB disease diagnosis and treatment. These innovative techniques offer advantages paving the way for enhanced clinical management of PB diseases. Further research is warranted to establish their standard clinical utility and explore new frontiers in PB disease management.

Keywords: endoscopy; image‐enhanced endoscopy; pancreatobiliary; red dichromatic imaging; texture and color enhancement imaging.

FIGURE 1

Endoscopic imaging‐object‐oriented classification.

FIGURE 2

Chromoendoscopy with indigo carmine for ampullary tumors. Indigo carmine enhances the surface structure and boundaries of the tumors (a) and clarifies bile secretion to facilitate the recognition of the biliary orifice (green arrowhead) (b).

FIGURE 3

Intraluminal injection of indigo carmine for identifying the afferent limb during balloon enteroscopy‐assisted endoscopic retrograde cholangiopancreatography.

FIGURE 4

(a) In white light imaging, the pancreato‐jejunal anastomosis stenosis is not discernible. (b) Spraying indigo carmine reveals the depression of the pancreato‐jejunal anastomosis stenosis. (c) Indigo carmine accumulation in the depression is diluted by the secreted pancreatic juice (yellow arrowhead).

FIGURE 5

Narrow‐band imaging of ampullary tumors. With narrow‐band imaging, it is easier to recognize abnormalities in the surface and vascular structures. (a, b) White light imaging; (c, d) narrow‐band imaging.

FIGURE 6

Peroral cholangioscopy with narrow‐band imaging of bile duct lesions. (a) Laterally spreading papillary biliary lesions in white light imaging and (b) in narrow‐band imaging. (c) Nodular bile duct cancer with irregularly dilated and tortuous vessels in white light imaging and (d) in narrow‐band imaging.

FIGURE 7

Main mechanism of red dichromatic imaging.

FIGURE 8

Detection of the bleeding point (blue arrowhead) with red dichromatic imaging during post‐endoscopic sphincterotomy bleeding. (a) White light imaging and (b) red dichromatic imaging Mode 2. Owing to the characteristics of red dichromatic imaging, diluted blood appears transparent and bleeding points are depicted as orange.

FIGURE 9

Endoscopic variceal ligation for massive variceal hemorrhage around the cholangio‐jejunal anastomotic site after pancreaticoduodenectomy. (a) Poor visibility due to massive bleeding. (b) Gel immersion technique using Viscoclear (Otsuka Pharmaceutical Factory, Inc., Tokushima, Japan) secures visibility. (c) Red dichromatic imaging further improves the visibility of bleeding points (blue arrowhead) and reduces the mental load caused by the color of the blood. (d) Successful achievement of hemostasis with endoscopic variceal ligation.

FIGURE 10

Red dichromatic imaging during peroral cholangioscopy. (a) White light imaging, (b) narrow‐band imaging: Bile is depicted in red color, significantly impairing the field of vision. (c) Red dichromatic imaging: Even in the presence of bile, it is possible to clearly visualize the bile duct walls and vessels. (d) Intraductal papillary neoplasm of the bile duct in white light imaging, (e) narrow‐band imaging, and (f) red dichromatic imaging Mode 3.

FIGURE 11

Main mechanism of texture and color enhancement imaging (TXI).

FIGURE 12

Texture and color enhancement imaging (TXI) for identifying the biliary orifice (green arrowhead) of a naïve papilla. (a) White light imaging, (b) texture and color enhancement imaging Mode 1, and (c) texture and color enhancement imaging Mode 2.

FIGURE 13

Texture and color enhancement imaging for detecting the biliary orifice (green arrowhead) of an interdiverticular papilla. (a) White light imaging and (b) texture and color anhancement imaging Mode 2. [Reprinted with permission from Georg Thieme Verlag KG, originally published in Endoscopy 2022 ³⁵ ]

FIGURE 14

Texture and color enhancement imaging for detecting the biliary orifice (green arrowhead) after precut papillotomy. (a) White light imaging, (b) texture and color anhancement imaging Mode 2, (c) white light imaging, and (d) texture and color enhancement imaging Mode 2. [Reprinted with permission from Georg Thieme Verlag KG, originally published in Endoscopy 2022 ³⁶ ]

FIGURE 15

Texture and color enhancement imaging for recognition of boundaries of an ampullary tumor. (a) White light imaging, (b) texture and color enhancement imaging Mode 1, and (c) texture and color enhancement imaging Mode 2. [Reprinted with permission from John Wiley and Sons, originally published in Dig Endosc 2023 ⁴⁰ ]

FIGURE 16

Texture and color enhancement imaging for recognition of the biliary orifice (green arrowhead) of an ampullary tumor. (a) White light imaging, (b) texture and color enhancement imaging Mode 1, and (c) texture and color enhancement imaging Mode 2.

FIGURE 17

Texture and color enhancement imaging for detecting the biliary (green arrowhead) and pancreatic (blue arrowhead) orifice after endoscopic papillectomy, (a) White light imaging, (b) texture and color enhancement imaging Mode 2, (c) white light imaging, and (d) texture and color enhancement imaging Mode 2. [Reprinted with permission from John Wiley and Sons, originally published in Dig Endosc 2023 ⁴⁰ ]

FIGURE 18

Texture and color enhancement imaging for identifying the pancreato‐jejunal anastomosis site (blue arrowhead). (a) White light imaging and (b) texture and color imaging Mode 1. [Reprinted with permission from Georg Thieme Verlag KG, originally published in Endoscopy 2022 ⁴¹ ]

FIGURE 19

Texture and color enhancement imaging during peroral cholangioscopy. Enhanced color and brightness make it easier to recognize red areas or dilated vessels and detect lesions. (a) White light imaging, (b) texture and color enhancement imaging, (c) white light imaging, and (d) texture and color enhancement imaging.