Endoscopists' experience changes which visual features matter for classifying colorectal lesions.

Doctors use a special camera view to classify growths in the colon called serrated lesions. One category they look for is Japan NBI Expert Team Type 1. However, different doctors often disagree on which visual features they see when making this choice. Researchers wanted to see how doctors choose this label. They reviewed web test data where specialists and less experienced doctors examined images of growths. The team used decision trees to map which visual clues drove their choices between Type 1 and non-Type 1. They found that experts primarily based their first split on signs that argued against Type 1. In contrast, non-experts first split on seeing regular dark or white spots. The experts showed more stable visual patterns and less randomness. The non-expert patterns changed when unassessable answers were removed. These findings show pattern links rather than a proven diagnostic rule.

Why it matters

Doctors who look inside the colon often see suspicious growths called polyps. Their team's distinction between two polyp types—serrated lesions—affects whether a patient needs more surveillance or treatment. This study shows that expert and non-expert endoscopists rely on different visual clues to make that call, and experts are more consistent. That gap matters because it means training and experience directly influence diagnostic accuracy, which can change patient outcomes.

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