Table 1.

Overview of the n = 177 WSI used for AI training and analysis. Abbreviations: conv.: conventional (urothelial); NA: not assessable; ROI: Region of interest (i.e., tissue area used for training or analysis).

	Training Set			Validation Set
No. of slides	81			96
PCR	positive	negative		positive	Negative
	37	44		69	27
Mean ROI	256 ± 135 mm2 (entire tissue section)			14 ± 3 mm2 (epithelium only)
Quality	high	standard	poor	high	standard	poor
	80	1	0	34	19	43
PCR positive	37	0	0	27	15	27
PCR negative	43	1	0	7	4	16
Differentiation	conv.	non-conv.		conv.	non-conv.
	71	10		50	46
PCR positive	36	1		40	29
PCR negative	35	9		10	17
Invasion	present	absent	NA	present	Absent	NA
	44	36	1	34	23	39
PCR positive	22	15	0	23	19	27
PCR negative	22	21	1	11	4	12
Inflammation	present	absent	NA	present	Absent	NA
	32	49	0	39	56	1
PCR positive	15	22	0	28	40	1
PCR negative	17	27	0	11	16	0