Table 3 Summary of diagnostic imaging findings [14, 16, 22–29, 31]
Diagnostic imaging | Finding FL-HCC | Finding HCC in cirrhosis | Comments |
|---|---|---|---|
US | - Well-defined mass of variable echogenicity - Partially successful in demonstrating central scares as a central area of hyperechogenicity - Demonstrates calcification within the fibrous scar | - Lesions may appear hyperechoic, hypoechoic, or as target lesions, none of which is specific | - In general, nonspecific sonographic features - Less useful for demonstrating necrosis - Less accurate than CT and MRI in demonstrating regional lymphadenopathy - The optimal tool for screening HCC in cirrhosis |
CT | - Large tumor with well-defined margins - Lobulated or smooth surface - Calcification and a central scare - Areas of hypervascularity - Abnormal lymphadenopathy - Portal vein thrombosis and biliary obstruction are extremely rare - Generally tumors show a heterogeneous hypervascular enhancement | - Necrosis, hemorrhage, focal tumor fat, and invasion of vascular structures are common - Hypoattenuating to surrounding liver - Central scare, fibrosis, and calcification are rare - Arterial hypervascularity (elevated arterial flow), venous phase washout (reduced or absent portal venous flow) - Presence of fat | - In some cases of FL-HCC margins can be ill defined. - CT demonstrates calcification in FL-HCC better than MRI. - In CT a central scare is not pathognomonic of FL-HCC |
MRI | - Large tumor, hypointense on T1-weighted images and hyperintense on T2-weighted images - No calcification but a central scare - No fat component - Generally tumors show a heterogeneous hypervascular enhancement; hyperattenuating on the arterial phase, hypo-, iso-, or even hyperattenuating in venous phases | - Well-circumscribed borders - Low signal intensity on T1-weighted images and high signal intensity on T2-weighted images - Intratumoral fat - Tumor encapsulation - Portal or hepatic vein invasion - Arterial-portal venous shanting - Generally, variable in appearance depending on steatosis or hemorrhage | - MRI is considered to be competitive rather than complimentary to CT in most cases. - MRI demonstrates the central scare in FL-HCC better than CT - MRI is may be more sensitive in detecting small lesions |