Fig. 4.

Perfusion CT images in a patient with NET liver metastases. Conventional CT image depicts a hypervascular liver metastasis in the left liver lobe (white arrows). Parametric maps of blood flow (BF), permeability (PS), and time to peak (TTP) show a different functional behavior at the periphery of the metastatic deposit (black arrows) compared to normal liver or the center of the metastasis, with increasing BF and PS and decreasing TTP. Perfusion CT provides additional information compared to morphologic imaging that may have prognostic value or be useful in tumor response evaluation