Figure 3: Examples of MIP images of PAI for comparison of amounts of blood vessels between the affected side and the contralateral side.

The color of PA signal corresponded to the depth scaled by Fig. 1(g). Case 3 (Fig. 3(a–f)): A 40-year-old woman with IBC in upper-outer area of right breast. The tumor was 47 mm in diameter. (a) MIP image of the affected side and (b) MIP image of the contralateral side. Significant difference of blood vessel amounts was hardly seen between (a) and (b) due to many signals in both pictures. MIP image of (c) the affected side and (d) the contralateral side after eliminating the PA signals from subcutaneous blood vessels by a depth of 4 mm. The position of the tumor was indicated by a white dashed circle. Specific structure of blood vessels could be seen around the tumor in (c), whereas not in (d). Tumor-related blood vessels were made more visible by eliminating subcutaneous signals in coronal view. (e) and 3 (f) are slab MIP images observed from the Axial plane of (c) and (d). The section line was set on C - C’ corresponding to the tumor position and on D - D’ on the contralateral side. The width of each slab was set to 38 mm around the cross section line. Case 4 (Fig. 3(g–j)): A 44-year-old woman with multiple IBCs in upper area in left breast. MIP image of (g) the affected side and (h) the contralateral side after eliminating the PA signals from subcutaneous blood vessels by a depth of 4 mm. The position of the tumor was indicated by a white dashed-dotted circle. More signals were seen in the affected side than the contralateral side and centripetal blood vessel toward the tumor could be seen in (g). (i) and (j) are slab MIP images of the axial views of (g) and (h), of which the cross-section line was G-G’ and H-H’, respectively. The width of each slab was set to 38 mm around the cross section line.