Figure 4.

Schematic diagram illustrating the decrease in normal paired hepatic arterial supply and the increase in angiogenetic arterial supply as a nodule becomes more dysplastic and neoplastic. (Adapted from Hayashi M, Matsui O, Ueda K et al. Correlation between the blood supply and grade of malignancy of hepatocellular nodules associated with liver cirrhosis: evaluation by CT during intraarterial injection of contrast medium. AJR Am J Roentgenol 1999; 172: 969.) RN, regenerating nodule; LG, low-grade dysplastic nodule; HG, high-grade dysplastic nodule; WD, well-differentiated HCC; MD, moderately differentiated HCC; PD, poorly differentiated HCC. Note that there is a point in the continuum where the decrease in normal hepatic arterial supply is balanced by an increase in angiogenetic supply. This occurs in high-grade dysplastic nodules or well-differentiated HCC and explains the difficulty in diagnosis.