Comparison of OCT B-scans taken from the commercial system at 1300mm (a) (d) and UHR OCT system at 800nm (b) (e), and their histopathological correlations (c) (f). (a)–(c) demonstrate an example of normal breast tissue, with adipose, stroma and TDLUs. (d)–(f) demonstrate a subtype of IDC, known as mucinous carcinoma. Insets: zoom-in view of adipose region, covering 0.3mm by 0.3mm area. Scale bar: 250 μm.