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AIxURO provides objective measurement of N/C ratio and nuclear area in urine cytology, challenging the current TPS threshold (>0.7) for diagnosing HGUC. The study suggests that a revised N/C ratio cutoff of 0.66 may be more appropriate for SHGUC/HGUC categorization using AI. Findings also support the use of consistent thresholds across upper and lower urinary tract cases. Nuclear area offers additional discriminative value, particularly for differentiating CIS from HGUC.
Heuristic scanning showed improved scanning times and AI-aided cytologic interpretation while reducing overall image file size and maintaining similar scanning coverage for SHGUC+ cells for 3 urine cytology preparation types.
AI-assisted urine cytology review markedly reduces review time while increasing sensitivity and NPV using TPS2.0 compared to conventional microscopy. However, specificity, PPV and accuracy are slightly diminished. Pairing a cytopathologist (CP) with different cytologists (CT) also influences the diagnostic outcomes and metrics.
AI-assisted AIxURO outperformed microscopy in diagnostic accuracy for AUC while maintaining comparable accuracy across other TPS categories and significantly reducing total review time for all reviewers. WSI review alone did not improve diagnostic accuracy or efficiency.
Success Scanning Rates
Scanning Times (median)
File Image Sizes of WSI (using manual focus mode and 21 Z-layer scan settings)
Semi-automatic and manual focus modes provide the most successful slide scanning with rates up to 100%. A minimum of 9-layer Z-stacking at 1 µm intervals is necessary to cover 80% of atypical cells. Cytospin preparations take less time to scan and result in smaller file sizes than do ThinPrep slides, regardless of the scanner. Z-stacking enhances AI inferred quality and coverage rates of atypical cells but with longer scanning times and larger image files.
Overall, Hamamatsu scanner showed better performance for image quality in the manual mode than Roche scanners, which performed better in the default mode. Hamamatsu scanners also had improved detection of atypical urothelial cells among triplicate images from the same samples compared to Roche scanners.
Decreased sensitivity and PPV in differentiating AUC from NHGUC may be the result of the usual clinical workflow, where cytologists initially screen and mark suspicious regions as abnormal, but defer to CP for a more specific interpretation; it may also reflect less experience with digital cytology interpretation.
Overall, Hamamatsu scanner showed better performance for image quality in the manual mode than Roche scanners, which performed better in the default mode. Hamamatsu scanners also had improved detection of atypical urothelial cells among triplicate images from the same samples compared to Roche scanners.
The AI-assisted tool allowed for excellent performance to aid interpretation of upper GU tract urothelial carcinoma
AI-assistance improves the sensitivity and NPV of urine cytology review, but at the expense of a decrease in specificity, PPV and accuracy. This may indicate that AI-assistance will facilitate the detection of abnormal urothelial cells while lowering the time required for slide review.
