Fig. 5

Complete response correctly assessed both with contrast-enhanced spectral mammography (CESM) and magnetic resonance imaging (MRI). Complete response to neoadjuvant chemotherapy (NAC) in a 44-year-old woman with 30 mm in situ and invasive ductal carcinoma (G3, human epidermal growth factor receptor 2 (HER2)⁺) in the right breast, correctly assessed with CESM (a medio-lateral oblique recombined image; b, e craniocaudal recombined image) and MRI (c sagittal maximum intensity projection reconstruction; f axial post-contrast T1-weighted at peak enhancement). Pre-NAC (a, b, c, d), evaluation showed the same polygonal shape, well-defined margins and same size on CESM (a, b), on MRI (c) and on ultrasound (d). Background parenchymal enhancement (arrow) was visible both on CESM (a) and MRI (c), with no significant influence on the assessment of the size of the lesion. Post-NAC, no residual pathological enhancement was visible on CESM (e) or on MRI (f). Complete response was confirmed by histopathological examination of the surgical specimen