Liver tumors in children with chronic liver diseases

Table 3 Typical imaging appearances of liver tumors

Tumors	US with doppler	CT	MRI
HB	Well circumscribed hyperechoic or heterogenous echogenic lesion	Hypoattenuating lesion in non-contrast image with heterogeneous arterial and venous enhancement	T1W; hypointense
			T2W; hyperintense
			Heterogeneous arterial and venous enhancement
HCC	Variable from hypo-, iso-, or hyperechoic from internal fat, necrosis or hemorrhage	Well- or poorly defined, hypoattenuating lesion with arterial hyperenhancement and venous “wash-out” with/without delayed capsular enhancement	T1W; hypointense
			T2W; hyperintense
			Early arterial enhancement and wash-out with relative low signal intensity on venous and delayed phases
		Tumor thrombus enhancement in portal vein	Delayed capsular enhancement
FNH	Homogenous, well-circumscribed	Homogeneous, well-circumscribed iso- to slightly hypoechoic lesion	T1W; iso- to slightly hypointense with hypointense scar
			T2W; iso- to slightly hyperintense with hyperintense scar
		Hypoattenuating scar	Enhancement pattern same as CT
	Internal color flow in the central scar extending to the periphery in a spoke-wheel pattern	Arterial and early portal venous enhancement and becomes isoattenuating to liver in the late portal venous and delayed phases	Normal or increased uptake on delayed hepatobiliary phases of the hepatocyte specific contrast agent
Adenoma	Hyperechoic lesion in the normal liver	Well-circumscribed hypoattenuating lesion with hyperattenuation if hemorrhaging	T1W; hyperintense
			T2W; hyperintense
			Fat component; Signal dropout on opposed-phase or fat suppression images
	Hypoechoic lesion in the background of diffuse fatty infiltration or glycogen storage	Intense arterial enhancement and isoattenuating in venous and delayed phases	Peripheral pseudocapsular enhancement
			Enhancement pattern same as CT
NRH	Multiple tiny and typically isoechoic lesions, difficult to detect.	Slightly hypo- or isoattenuating lesion to liver	T1W; homogenous and slightly hyperintense.
			T2W; variable
		Isoattenuation to liver in both arterial and portal venous phases	Enhancement in portal phase like normal liver parenchyma

CT: Computed tomography; FNH: Focal nodular hyperplasia; HB: Hepatoblastoma; HCC: Hepatocellular carcinoma; MRI: Magnetic resonance imaging; NRH: Nodular regenerative hyperplasia; US: Ultrasonography.