A Prospective Study to Evaluate the Diagnostic Accuracy of Computer-aided Diagnosis (CADx) System in Real-time Characterization of Colorectal Neoplasia

Accurate diagnosis and characterization of colorectal polyps is essential before endoscopic resection. Optical diagnosis by enhanced imaging modality (e.g. Narrow Band Imaging, NBI) allows real-time prediction of histopathology. It can assist endoscopists to select the appropriate technique and differentiate between neoplastic or non-neoplastic polyps. Nevertheless, due to the substantial inter-observer variability, the widespread use was limited.

Recently, artificial intelligence and computer-aided polyp diagnosis (CADx) systems have evolved rapidly. The major limitation was the heterogeneity from different types of imaging modalities. Endocytoscopic images require extra steps for pre-staining and magnification, which are time consuming and operator dependent. As a result, it limits the generalisability and applicability in real-world settings.

A novel CADx system will be developed for real-time histopathological prediction of colorectal neoplasia, by using non-magnified conventional white-light and image enhanced endoscopy (NBI). The diagnostic accuracy of this CADx system will be compared with both expert and junior endoscopists.

Inclusion criteria

• They have received colonoscopy for screening, surveillance or symptom investigation;
• They have endoscopic images and videos captured and stored during colonoscopy which are available to be retrieved;
• They have histologically proven colorectal neoplasia.
• Written consent obtained

Exclusion criteria

• Poor quality endoscopic images and videos defined as:

• Incomplete visualization of the colorectal neoplasia due to technical reasons (e.g. out-of-focus, motion-blurred or insufficient illumination);
• Artifacts due to mucus, air bubbles, stool, or blood.
• Active gastrointestinal bleeding;
• Fulminant colitis;
• Obscured view due to poor bowel preparation;
• Artificial staining of lesion due to chromoendoscopy.
• Unable to obtain informed consent