FIG 2. Examples of dynamic CT-measured contrast-enhancement curves of an artery (line), normal tissue (squares), and tumor (circles) in a rabbit with brain tumor. For clarity, the tissue curves are displayed using a different scale of CT numbers (right axis). Thus, the arterial enhancement curve (left axis) is more than 10 times higher than that of the tumor curve, and 50 times higher than that of the normal tissue curve. Note the higher washout phase of the tumor curve relative to the normal tissue.FIG 3. Contrast-enhanced CT image illustrating tumor, peritumor and contralateral normal ROIs found in a rabbit. The radial arteries (RA) are clearly displayed at the bottom of the figure (adjacent to the radial and ulna bones)