Representative color-coded maps for plasma flow (F<sub>p</sub>) pre (A) and post therapy (B).

<p>Plasma Flow (F<sub>p</sub>) values [mL/100 mL/min] are coded according to the vertical color scale. For demonstration purposes only and in contrast to the actual plasma flow assessment, pixel-wise analysis has been conducted here in order to create color-coded maps for a better visualization of the effects of regorafenib therapy. As their position relative to the tumor remains constant, vertebral bodies were used as topographic landmarks to assure analysis of comparable tumor slices. Note the adducted left lower limb in the post therapy image, which does not have an effect on tumor position. Before regorafenib therapy, we observed a highly perfused tumor with a hyperperfused rim (A). After regorafenib therapy, tumor perfusion has declined significantly, predominantly in the center of the tumor (B).</p>