Fluorescein as a topical fluorescent contrast agent for quantitative microendoscopic inspection of colorectal epithelium.

Sandra P Prieto,Keith K Lai,William C Mustain,Jonathan A Laryea,Jason S Mizell,Timothy J Muldoon

doi:10.1364/boe.8.002324

Abstract

Fiber bundle microendoscopic imaging of colorectal tissue has shown promising results, for both qualitative and quantitative analysis. A quantitative image quality control and image feature extraction algorithm was previously designed for quantitative image feature analysis of proflavine-stained ex vivo colorectal tissue. We investigated fluorescein as an alternative topical stain. Images of ex vivo porcine, caprine, and human colorectal tissue were used to compare microendoscopic images of tissue topically stained with fluorescein and proflavine solutions. Fluorescein was shown to be comparable for automated crypt detection, with an average crypt detection sensitivity exceeding 90% using a combination of three contrast limit pairs.

Highlights

Microendoscopy is an emerging method which can provide clinicians with in vivo information on tissue microstructure that is not readily visible using traditional colonoscopy and endoscopy
When imaging with wide field modalities, such as the microendoscopy system studied in this manuscript, we have shown that topical application of fluorescein is sufficient to highlight crypt structures, while topical delivery via an auxiliary endoscopy probe channel might minimize the amounts of systemic contrast agent [25]
We have evaluated the ability of topical proflavine and fluorescein to provide contrast in colorectal epithelium using end-on fiber bundle microendoscopy imaging of bulk ex vivo tissue

Summary

Introduction

Microendoscopy is an emerging method which can provide clinicians with in vivo information on tissue microstructure that is not readily visible using traditional colonoscopy and endoscopy It allows for histology-level detail to be acquired in real-time, with the potential for in vivo guidance for the clinician, such as in targeted biopsies [1,2]. The precursor of colorectal malignancy is dysplasia and there is a long lag phase between the onset of dysplasia, and the development of malignancy [9]. Detecting these regions prior to becoming clinically evident will further help in preventing colorectal cancer [10]. Several microendoscopy imaging studies are aimed at improving early detection of glandular epithelial dysplasia, and providing biopsy guidance and prognostic indicators in clinical settings [2, 12,13,14]

Methods

Results

Conclusion