Figure 9: This is the same 41-year-old patient shown in Figure 3. The cancer is in the left breast, and the breast density is measured from the normal breast in the right side. From (a) to (d), the non-fat-sat T1-weighted images selected from the same level in pretreatment, F/U-1, F/U-2, and F/U-3 MRI are shown. It is noticed that the normal breast density decreases with chemotherapy. The measured percent density (fibroglandular tissue volume divided by the breast volume) is 13.4% before treatment, which decreases to 9.2% in F/U-1 after receiving 2 cycles of AC regimen and further down to 8.7% in F/U-2 and 8.2% in F/U-3.