Table 1.

Statistics of the breast cancer screening datasets

Dataset	Device	Country	Type	N cases	N images	% positives images
Scanner A	Hologic	UK	Reference set $D_{ref}$	3221	12,884	2.5%
Scanner B	IMS Giotto	Hungary	Unseen	4152	16,608	1.8%
Scanner C	Siemens	UK	Unseen	3904	15,616	1.9%
Scanner D	GE Healthcare	UK	Unseen	4115	16,460	1.8%

Source data are provided as a Source Data file.