|
Condition |
Ultrasonography |
CT |
|
Hemangioma |
Hemangiomas sized <3 cm in diameter are visible as oval, hyperechoic, and well-defined structures in the liver parenchyma; larger hemangiomas usually have heterogeneous echostructure; little or no signal is observed on Doppler examination (very slow blood flow) |
On plain CT scan hemangioma is visible as a hypodense, oval, well-demarcated and uniform lesion with a centripetal (inward) fill-in after contrast administration; small lesions (<3 cm) may show uniform or centrifugal enhancement (from the center outwards) |
|
FNH |
Hypo- or hyperechoic lesion, hypervascular in the arterial phase on Doppler examination, (unlike hepatocellular adenoma, for which the venous signal is characteristic) |
Before contrast administration the tumor is hypo- or isodense; after rapid contrast injection, an arterial vessel is visible within the central fibrous scar in the arterial phase; characteristic fibrous septa and central scar are usually visible in lesions >3 cm |
|
Hepatocellular adenoma |
Hypo-, hyper-, or iso-echoic lesion with a predilection for subcapsular regions of the right lobe; the image is often heterogeneous and can have visible calcifications inside; may be surrounded by a hypoechoic zone; in 40%-60% of cases the lesion is hypervascular in the arterial phase on Doppler examination, but to a lesser extent than in FNH, and shows centripetal filling (opposite to FNH, which shows centrifugal filling) |
Hemorrhagic changes are visible as hyperdense foci; the lesion shows rapid centripetal post-contrast filling in the early arterial phase and becomes isodense again in the portal phase |
|
Hepatocellular carcinoma |
Iso-, hypo-, or hyperechoic tumor; often heterogeneous; with a characteristic hypoechoic rim with clearly pronounced [post-contrast] enhancement; sometimes signs of portal vein thrombosis |
The lesion is hypodense and heterogeneous on plain CT with density increasing nonuniformly following contrast administration in the arterial phase; use the LI-RADS criteria for imaging diagnosis |
|
Simple cyst |
Anechoic, homogeneous lesion filled with fluid, with smooth margins |
A well-defined, smooth lesion with water density, no internal structure, not enhancing after contrast administration |
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Polycystic liver disease |
Numerous simple cyst–like sacs |
Numerous simple cyst–like sacs |
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Echinococcal cyst
|
– Initially similar to simple cysts – Thick, calcified walls with hyper- or hypoechoic contents gradually develop – Daughter cysts may be seen peripherally |
– Hypodense lesion with a highly vascularized wall and internal cysts – Calcified walls and septa – Daughter cysts visible peripherally |
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CT, computed tomography; FNH, focal nodular hyperplasia; LI-RADS, Liver Imaging Reporting and Data System. |
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