A 64-year-old patient with a well-circumscribed, triple-negative, mass lesion (invasive ductal cancer) in the left breast. The maximum intensity projection (MIP) images of pre-treatment, F/U-1, and final MRI are shown. The tumor size is 2.5 cm before treatment and shows concentric shrinkage to 1.8 cm in F/U-1 and further down to 1.1 cm in final MRI after completing treatment. The residual tumor size determined in post-NAC pathological examination is 1.4 cm, and the MRI discrepancy is 3 mm. This is a true positive case.