Digital Microscopy in the Endoscopy Suite: A Reference Standard for Colorectal Polyp Size Measurement

Area of Science:

• Gastroenterology
• Medical Imaging
• Artificial Intelligence

Background:

• Accurate colorectal polyp size determination is vital for patient surveillance and AI ground truth.
• Current visual estimation methods lack precision, and a validated reference standard is absent.
• This study addresses the need for a reliable method to measure polypectomy specimens.

Purpose of the Study:

• To assess the accuracy and reproducibility of real-time digital microscopic measurement of fresh colorectal polyps.
• To establish a validated reference standard for polyp sizing.
• To evaluate the utility of digital microscopy for AI development.

Main Methods:

• Prospective study involving 70 polyps from 44 patients.
• On-site measurement using a calibrated digital microscope.
• Three blinded raters performed long- and short-axis measurements.

Main Results:

• Excellent inter-rater reliability for both long-axis (ICC 0.941) and short-axis (ICC 0.943) measurements.
• Bland-Altman analysis showed minimal bias, with limits of agreement within ±1 mm.
• Perfect agreement (κ=1.0) was achieved when classifying polyps at the 5 mm threshold.

Conclusions:

• On-site digital microscopy provides highly reproducible and verifiable polyp size data.
• This method serves as a practical reference standard for polyp sizing research and AI model development.
• The technique meets regulatory expectations for traceable and auditable training data.