1.5 t mr imaging system

Each patient underwent MRI prior to NCT (MR1), after the first cycle of treatment and before the second cycle of treatment (MR2), and after completing NCT (MR3). Multiparametric breast MRI was performed in the prone position with a 1.5 T MR imaging system (GE Medical Systems, Milwaukee, WI, USA and Achieva, Philips Healthcare, Best, Netherlands) with a 8-channel dedicated breast coil. Patients were in a prone position to obtain images before and after administration of 20 ml of gadopentetate dimeglumine (Bayer Health Care Pharmaceuticals, Osaka, Japan) at an injection rate of 3 mL/s. DW images of both breasts were acquired in the transverse plane. A spin-echo, single-shot echo planar imaging sequence with diffusion-sensitizing gradients applied in the orthogonal directions was used. DW imaging also included two b-values, 0 s/mm² and 750 s/mm², with the latter recommended in a previous study^{15 (link)}. After DWI, five three-dimensional (3D), T1-weighted gradient-echo sequences with fat suppression were obtained in the axial plane. The first image was obtained prior to the administration of contrast reagent and the last sequence consisted of post-contrast images.