A detailed comparison between the endoscopic images using blue laser imaging and three-dimensional reconstructed pathological images of colonic lesions.

Chiho Ohbayashi,Masayuki Sho,Takeshi Ueda,Tadashi Nakagawa,Takashi Inoue,Maiko Takeda,Hiroyuki Kuge,Shinji Nakamura,Fumikazu Koyama,Yuichi Teramura,Kohei Morita,Hisao Fujii,Yoshiyuki Sasaki,Takayuki Nakamoto,Yayoi Matsumoto

doi:10.1371/journal.pone.0235279

Abstract

Blue laser/light imaging (BLI) is an image-enhanced endoscopy (IEE) technique that can provide an accurate diagnosis by closely observing the surface structure of various colonic lesions. However, complete correspondence between endoscopic images and pathological images has not been demonstrated. The aim of this study was to accurately compare endoscopic images and the pathological images using a three-dimensionally (3D) reconstructed pathological model. Continuous thin layer sections were prepared from colonic tissue specimens and immunohistochemically stained for CD34 and CAM5.2. Three-dimensional reconstructed images were created by superimposing immunohistochemically stained pathological images. The endoscopic image with magnifying BLI was compared with the top view of the 3D reconstructed image to identify any one-to-one correspondence between the endoscopic images and histopathological images using the gland orifices and microvessels as a guide.Using 3D reconstructed pathological images, we were able to identify the location on the endoscope image in cases of colonic adenocarcinoma, adenoma and normal mucosa. As a result, the horizontal plane of the endoscopic image and the vertical plane of the 2D pathological specimen were able to be compared, and we successfully determined the visible blood vessel depth and performed a detailed evaluation on magnifying BLI. Examples are as follows: (1) The median vasculature depth from the mucosal surface that could be recognized as vasculature on magnifying BLI was 29.4 μm. The median depth of unrecognizable vessels on magnifying BLI was 218.8 μm, which was significantly deeper than recognizable vessels. (2) Some brownish structures were suggested to potentially be not only dense vessels, vessel expansions, corrupted vessels but also bleeding or extravasation of erythrocytes. Overall, we demonstrated a new approach to matching endoscopic images and pathological findings using a 3D-reconstructed pathological model immunohistochemically stained for CD34 and CAM5.2. This approach may increase the overall understanding of endoscopic images and positively contribute to making more accurate endoscopic diagnoses.

Highlights

In recent years, newly developed image-enhanced endoscopy (IEE) techniques, such as narrow banding imaging (NBI), blue laser/light imaging (BLI) and linked color imaging (LCI) have enabled the observation of the surface structure of various colonic lesions using narrow-band laser light [1,2,3,4]
We focused on one of visible blood vessels that disappeared on magnifying BLI, and the corresponding blood vessel running from near the mucosal surface to the deep area could be tracked on the adjacent histopathological images (Fig 6)
We demonstrated that the 3D reconstructed image of the microscopic multi-slice images immunohistochemically stained with CAM5.2 and CD 34 made it possible to compare the top view of the tissue and the endoscopic image

Summary

Introduction

Newly developed image-enhanced endoscopy (IEE) techniques, such as narrow banding imaging (NBI), blue laser/light imaging (BLI) and linked color imaging (LCI) have enabled the observation of the surface structure of various colonic lesions using narrow-band laser light [1,2,3,4]. NBI and BLI with magnification can predict the histopathological diagnosis and invasion depth with good diagnostic effectiveness [1,2,3] These studies have shown that the patterning of endoscopic images is associated with an increased pathological diagnostic accuracy. Other studies have pathologically analyzed the microvessel count, diameter and depth from the surface in hyperplastic polyp or adenoma, and reflected these findings in endoscopic findings [5,6,7] In these studies, the authors classified the endoscopic findings to predict the most invasive tumor depth or histological diagnosis, and what was observed in endoscopy was not necessarily directly reflected by the pathological findings. The aim of this study was to compare the endoscopic findings and the pathological microstructures using the 3D reconstruction of microstructures and microvessels on the surface of colonic tumors to establish a one-to-one correspondence

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