Fortuitously discovered liver lesions

Table 4 Typical enhancement pattern for the characterization of focal liver lesions

Lesion	Arterial phase	Portal venous and late phase
Hemangioma (Figures 1 and 2)	Circular vascular enhancement without central intratumoral vessels	Nodular enhancement and "fill-in" pattern
Focal nodular hyperplasia (Figures 3 and 4)	Radial centrifugal or "spoke wheel" pattern, then rapid, complete hyperhancement	Iso- or hyperenhancement
Focal fatty sparing (Figure 5)	Central arterial blood supply	Isoenhancement
Metastasis (Figure 6)	Asymmetrical, chaotic enhancement configuration	Hypoenhancement
Hepatocellular carcinoma (Figure 7)	Hyperenhancement and disorganized vascularity	Iso- or hyperenhancement, depending upon tumor differention

Reproduced with permission from reference Dietrich et al[81].