Review
Copyright ©The Author(s) 2015.
World J Gastroenterol. Jul 28, 2015; 21(28): 8541-8561
Published online Jul 28, 2015. doi: 10.3748/wjg.v21.i28.8541
Table 1 Imaging features
USComputed tomographyMagnetic resonance imaging
Infantile hepatic hemangioendothelioma
2DPre-contrast examinationT1-weighted images
Hypoechoic1Hypodense1, well-definedHypointense1
Doppler USPost-contrast examination± hyperintense foci2
Enlarged hepatic arteries and veins, shuntsIntense, homogeneous enhancement3/peripheral enhancement4 with progressive centripetal filling-in patternT2-weighted images
CEUSHyperintense
Peripheral enhancement, with centripetal filling-inEnhancement pattern
Centripetal filling-in
Mesenchymal hamartoma
2DCystic componentsCystic components
Cystic and solid5 components in various amounts6Water attenuationT1-weighted images
Thin/thick and mobile septaNon-enhancementVariable signal intensity on (depending on the protein content)
Parietal nodules
Rare features7T2-weighted images
High signal intensity
Doppler USSolid componentsSolid components
Linear blood flow within solid portions and septaHypodenseHypointense on both T1- and T2-weighted images (fibrosis)
Surrounding portal and hepatic veins may be displacedPost-contrast enhancement
CEUSPost-contrast mild enhancement (and within the septa)
Solid component may present arterial and portal venous enhancement
Focal nodular hyperplasia
2DPre-contrast examinationT1-weighted images
Well-circumscribedIsodense/slightly hypodenseIsointense/slightly hypointense to the liver
Variable echogenicityHypoattenuating central scarHypointense central scar
Stellate hyperechoic central scarArterial and early portal phasesT2-weighted images
Doppler USHomogeneous enhancement, earlier and more intense than the surrounding liver parenchymaIsointense/slightly hyperintense
Spoke-wheel patternHypoattenuating central scarHyperintense central scar
CEUSLate portal and delayed phasesArterial phase
Arterial and portal venous enhancementIsoattenuating to the liverHyperintense lesion
Delayed enhancement of the central scarNon-enhanced central scar
Portal venous phase
Slightly hyperintense/isointense
Delayed phase
Enhancement of the central scar
Nodular regenerative hyperplasia
2DPre-contrast examinationT1-weighted images
Multiple, tiny, well-circumscribed, hypo-/isoechoic nodules8Hypo-9/isoattenuating to the liverSlightly hyperintense
± sonolucent rimPost-contrast images± foci of high signal intensity11
CEUSNodules do not enhance9± hyper-/hypointense rim
Arterial and portal venous enhancement similar to the surrounding liver parenchymaDiffuse or peripheral rim-like enhancement10Fat suppressed images decreased signal intensity12
T2-weighted images
Iso-/hypointense
± hyperintense rim
Enhancement pattern
Similar to normal liver parenchyma13
Hepatic adenoma
2DPre-contrast examinationT1- and T2-weighted images
HeterogeneousHypoattenuating, sharply delineated spherical mass ± pseudocapsuleHeterogeneous, predominantly hyperintense20
Hyperechoic14/hypoechoic15/cyst-like16Heterogeneous content17In-phase and out-of-phase T1 sequence
Doppler USArterial phaseSignal loss (fatty components)
Central vessels with a triphasic pattern/continuous venous waveformHomogeneous18/heterogeneous enhancement19Enhancement pattern
CEUSPortal venous and delayed phasesEarly arterial enhancement
Only arterial enhancement as the distinctive feature to FNHIsoattenuating/rapid “wash-out”Isointense during portal and venous phases21
Hepatocyte-specific contrast agents
Hypointense on hepatocyte phase imaging