Figure 2.

(a) The T1-weighted image of a rat bearing a necrotic tumor. The peak Gd-DTPA enhancement on the tumor is overlaid on the anatomical image. The tumor region shows low Gd-DTPA enhancement (blue to green color) toward the inner aspect of the tumor, indicating the tumor has outgrown the nutrition supply and the tissue undergoes necrosis. However, the boundary (red color) still shows good blood perfusion due to the robust angiogenesis on the tumor margin. (b) The ICG enhancement maps without and with MRI anatomical information are shown in the first and second row, respectively. The baseline absorption maps are shown in the first column. The next five columns of images show a time-lapse series of absorption enhancement. The tumor can be clearly seen at the peak ICG uptake (170 s) as the highest absorption area.