patterns of enhancement in hepatocellular carcinoma
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1. Hepatocellular carcinoma (HCC) appears as hyperenhancing lesions during the hepatic arterial phase of contrast enhanced CT or MRI due to its hypervascular nature. These lesions wash out during the portal venous phase. 2. Multiphase contrast enhanced imaging is important for diagnosing HCC as it allows evaluation of changes in intra-tumoral blood flow during different phases. Arterial phase hyperenhancement combined with washout or capsule appearance has near 100% specificity for HCC. 3. While imaging features such as arterial phase hyperenhancement and washout are characteristic of HCC, they are not entirely specific, and HCC must be differentiated from other malignancies and benign lesions.
patterns of enhancement in hepatocellular carcinoma
- 1. PATTERNS OF EHNACEMENT IN HEPATOCELLULAR CARCINOMA Dr. Haseeb Manzoor Department of Radiology Shalamar Hospital
- 2. •Diagnosis of HCC larger than 2 cm can be made without biopsy ! if, •A mass in a cirrhotic liver shows the typical features of HCC on contrast-enhanced CT or MRI •α-fetoprotein level is greater than 200 ng/mL
- 3. •Any solid lesion in a cirrhotic liver that is not a hemangioma is considered HCC until proven otherwise. •Imaging may be used to establish diagnosis of HCC non-invasively.
- 5. •Contrast agents permit diagnosis of HCC based mainly on the physiologic changes in intra-nodular blood flow. •To evaluate these changes, multiphasic examinations are performed. •Typically, contrast agents are administered at rates of; •5 mL/sec for CT •2 mL/sec for MR
- 6. Phase Comments Pre-contrast Serves as a baseline to gauge subsequent enhancement. Hemorrhage, calcification, central scar or gross fat may be seen within the HCC tumor. May be omitted to reduce radiation dose. Late hepatic arterial phase Characterized by full enhancement of the hepatic artery and its branches as well as enhancement of the portal vein. Fixed delay is not reliable. Critical for detection and characterization of hypervascular HCC.
- 7. Phase Comments Portal venous phase characterized by enhancement of hepatic veins as well as portal veins. acquired at around 60–80 seconds after the start of contrast agent injection. Delayed phase acquired at 3–5 minutes after the start of contrast agent injection. critical for characterizing washout appearance and capsule appearance. To differentiate small HCCs from small ICCs.
- 8. A C B D
- 9. •What to look for ? •Hypodense on precontrast images •Hyperdense during hepatic arterial phase •Hypodense during portal venous phase •Isodense during delayed phase
- 10. • Hepatocellular carcinoma in a 45-year-old man with hemophilia and hepatitis C cirrhosis. • Axial arterial phase CT shows hyperenhancement of the exophytic mass (arrow). • Delayed phase CT scan shows washout of contrast agent within the mass (arrow).
- 11. •The combination of arterial phase hyperenhancement + capsule appearance strongly suggests the diagnosis of HCC, even in the absence of washout appearance.
- 12. • 57 year old female with cirrhosis and HCC treated with RFA. • CT in arterial (a) and venous (b) phases shows enhancement and washout of a nodule adjacent to an RFA ablation zone.
- 14. Feature Comments Arterial phase hyper- enhancement Characteristic of but not specific for progressed HCC. Differential diagnosis: benign perfusion alterations, small hemangiomas, non-HCC malignancy e.g small ICC, small hypervascular metastases e.g neuroendocrine tumors. Washout appearance Characteristic of but not specific for progressed HCC. Differential diagnosis: cirrhotic nodules and dysplastic nodules. Pitfall: Focal areas of parenchymal distortion and enhancing fibrosis may create false perception of “washout.”
- 15. • 54 year old male with hepatitis C cirrhosis. • CT shows an arterial enhancing nodule with washout of contrast in the delayed phase consistent with hepatocellular carcinoma
- 16. Feature Comments Capsule appearance Presence of a capsule or a pseudocapsule differentiates HCC from regenerative and dysplastic nodules. Pitfall: peripheral enhancement of intrahepatic cholangiocarcinoma and fibrous tissue surrounding cirrhotic nodules and dysplastic nodules may be mistaken for capsule appearance. Arterial phase hyperenhancement plus washout or capsule appearance Diagnostic of HCC. In patients at risk for developing HCC, this combination has near 100% specificity. Limitation: early HCCs, small progressed HCCs, infiltrative HCCs may not exhibit this combination.
- 17. • 52-year-old man with combined hepatocellular carcinoma (HCC) and cholangiocarcinoma. A, arterial phase, tumor shows strong enhancement (arrowheads). portion of tumor shows low attenuation without enhancement (arrow). Thin hyper-enhancing capsule around mass is seen. B, portal venous phase, mass shows low attenuation due to washout of contrast medium.
- 19. Feature Comments Intra-lesional fat Characteristic of but not specific for early HCC. Differential diagnosis: low-grade and high-grade dysplastic nodule. Limitation: often coincides with other more discriminatory imaging features. Nodule in nodule architecture Suggests emergence of progressed HCC within dysplastic nodule or early HCC. Limitation: uncommonly depicted in CT or MR imaging
- 20. • 52-year-old man with focal fat within hepatocellular carcinoma. A, arterial phase, hyperattenuating mass (arrowheads). Focal area of hypoattenuation (–60 HU) (arrow) within lesion suggests fat. B, Portal venous phase, hypoattenuation throughout lesion (arrowheads). Focal area of fat (arrow) remains unchanged.
- 21. Feature Comments Corona enhancement Characteristic of progressed, hypervascular HCC. Helps to differentiate progressed, hypervascular HCC from vascular pseudolesions e.g arterioportal shunts. Limitations: May be difficult to recognize at CT or MR imaging. Pitfall: May overlap and blend with tumor enhancement, causing tumor to appear larger than it really is. Mosaic architecture Defined by the presence of multiple internal tumor nodules, fibrous septations and areas of hemorrhage, necrosis, fatty metamorphosis. Characteristic of and frequently observed in large HCCs. Helps in the differentiation of HCC from ICC. Limitation: uncommon in small HCCs
- 22. • Corona (arrow) manifested as a peritumor enhancing rim at the portal venous phase (A), • fades at delayed phase (B). • plain scan (C) shows a mosaic architecture (*) with lower attenuation within tumor. • more clear at portal venous phase (D).
- 23. Growth Patterns
- 24. •Solitary mass: •Bulk in one lobe with satellite nodules •HCCs exceeding 2 cm in diameter are known as “large HCCs” •Large HCCs tend to have higher histologic grade, more aggressive biologic behavior, higher frequency of vascular invasion and metastasis.
- 25. • HCC in a 58-year-old man with hepatitis C cirrhosis. • (a) arterial phase CT shows hyperenhancement of a solitary 4-cm mass (arrow). • (b) portal venous phase CT shows washout (arrow).
- 26. •Multifocal small nodular: •Defined by the presence of tumor nodules unmistakably separated by intervening non- neoplastic parenchyma. •Small foci of usually <2 cm in both hepatic lobes
- 27. • 55 year female. • Cirrhotic liver with multifocal hepatocellular carcinoma
- 28. •Diffuse infiltrating form: •Tiny indistinct nodules closely resembling cirrhosis.
- 29. • 64-year-old man with infiltrative HCC and macrovascular invasion • (a) late arterial, (b) portal venous, (c) 3-minute delayed phases. • patchy areas (*) of arterial phase hyper-enhancement and delayed phase partial washout appearance.
- 32. Nodule Type Unenhanced CT Arterial Phase Venous Phases Cirrhotic nodule Iso Iso Iso Or hypo High-grade dysplastic nodule Iso or hyper Iso or hypo Iso or hypo Early HCC Iso Iso or hypo Iso or hypo Progressed HCC Iso or hypo hyper hypo
- 34. Type Comments Clear cell fat is frequently present. decreased attenuation on unenhanced CT. Fibrolamellar Not associated with hepatitis or cirrhosis. solitary, well-defined, lobulated mass. Sarcomatoid Aggressive. No capsule, intratumoral fat, or central scar. Combined HCC- cholangiocarcinoma characteristics depend on the proportions of tumor components Sclerosing Rare intense fibrosis
- 35. • 32-year-old man with fibrolamellar HCC. • arterial phase CT (arrow) shows subtle peripheral enhancement. • portal venous phase, peripheral portion of tumor shows isoattenuation (arrowhead) relative to surrounding liver. Central portion of tumor shows low attenuation.
- 36. • 63-year-old man with sarcomatoid HCC. • A, arterial phase CT shows well-defined lobulated mass with peripheral enhancement. B, Equilibrium phase CT shows hypoattenuated peripheral portion of mass relative to surrounding liver. Central portion of mass shows no enhancement, which reflects necrosis.
- 37. Practice Cases
- 38. 48 years old male. Hepatomegaly. multiple heterogeneously enhanced nodules. Rapid wash-out.
- 39. • 86 years old male. • Multiple heterogeneous enhancement of lesions in segment VII and VIII of liver. • Rapid wash-out • hepatic sub-capsular collection (probably blood)
- 40. • 48years old male. cirrhosis and Hep C. • Enhanced heterogeneous masses in the III and IV segments • Rapid wash-out • Ascites
- 41. • 79 years old male. • Multiple enhanced heterogeneous lesions in I, IV, VII And VIII segments. • Rapid wash-out
- 42. • 52-year-old woman. A, portal venous phase, large hypoattenuating HCC (arrowheads) with extension of tumor into common bile duct (arrow). B, Coronal CT image shows tumor extension into common bile duct (arrow) and mild dilatation of intrahepatic biliary ducts (arrowheads). Gallbladder (asterisk) is moderately distended.
- 43. 56-year-old man with jaundice. A, early hyperattenuation of HCC (white arrow) but hypoattenuation within cholangiocarcinoma (black arrow). biliary ductal dilatation (Arrowheads). B, delayed phase, hypoattenuation of HCC (white arrow) and some delayed hyperattenuation within cholangiocarcinoma (black arrow).
Editor's Notes
- #30: heterogeneously enhancing soft tissue expanding the lumen of the right portal vein (arrowheads). arterial phase hyperenhancing tumoral arteries (arrows), sometimes described as “threads and streaks,” within the intraluminal tissue.