Validation of a Low-Cost Whole Slide Imaging System for Pathological Diagnosis of Gastric Ulcers in Biopsy Specimens by Pathology Residents.

OBJECTIVE

This study aimed to validate a low-cost whole slide imaging (WSI) system, the MoticEasyScan Pro 6 (Motic, Hong Kong), combined with consumer-grade laptops, for the evaluation of gastric ulcer biopsies by pathology residents.

METHODS

Sixty-six gastric biopsy slides were scanned at 40× magnification and reviewed by nine pathology residents across three training levels. Each resident interpreted both digital and glass slides for malignancy, Helicobacter pylori (H. pylori), and intestinal metaplasia (IM) subtypes, with a one-month washout period between formats. Diagnostic agreement was assessed using percentage agreement and kappa statistics, while paired t-tests were used to compare diagnostic times.

RESULTS

Diagnostic agreement between digital and glass slides was highest for malignancy (93.8%, almost perfect), followed by IM (82.6%, substantial) and H. pylori (67.8%, fair). Agreement for incomplete IM was significantly lower than for complete IM (70.6% vs. 82.4%, p = 0.02). Discordant diagnoses most frequently involved mild H. pylori infection and incomplete IM. Six of nine residents required more time to evaluate digital slides compared to glass slides (138 vs. 90 seconds, p < 0.01), though diagnostic accuracy and time taken were not correlated with training level. Factors contributing to low diagnostic agreement included subtle histologic features, misinterpretation of pseudogoblet cells, overlooked small foci of IM, and inconspicuous microorganisms.

CONCLUSION

Low-cost WSI systems are feasible for resident training in gastric ulcer biopsy interpretation, especially for distinguishing malignancy. However, lower agreement for H. pylori and incomplete IM highlights the challenges of recognizing subtle histologic features on digital slides. Incorporating structured digital pathology training and increasing exposure to WSI during residency may improve diagnostic performance.