- Flash-filling hemangiomas more likely to demonstrate perilesional perfusional alterations
- Reflects either increased arterial inflow or arterioportal shunting resulting in contrast overflow into perilesional sinusoids
- Giant hemangiomas (>4-5cm) may demonstrate a central nonenhancing “scar”
- This can be differentiated from FNH, fibrolamellar HCC, or cholangiocarcinoma as the scars in these usually enhance late whereas the scar in giant hemangioma typically does not enhance
- Will also have the same overall enhancement pattern of a hemangioma
- Hemangioma can grow on occasion (sometimes with exogenous estrogens)
- They usually disappear in cirrhosis
- They do not undergo malignant transformation and spontaneous rupture is exceedingly rare
- Main rare possible complication is Kasabach-Merritt syndrome