Imaging features and management of focal liver lesions

Table 1 Technical considerations for computed tomography and magnetic resonance imaging

	CT	MRI
Recommended equipment	Multidetector CT with minimum of 8 detector rows	1.5 Tesla or 3 Tesla
	≤ 5 mm axial reconstructed slice thickness	Phased array multichannel torso coil
	Dual-chamber injector with a saline flush	Current-generation high-speed gradients
		Dual-chamber power injector
Contrast injection rate	≥ 3 mL/s of contrast, ≥ 300 mg iodine/mL	2-3 mL/s of gadolinium chelate
	1.5 mL/kg of body weight
Required images	Arterial phase (late arterial phase strongly preferred over early arterial phase)	Unenhanced T1-weighted in phase and opposed phase imaging
	Portal venous phase	T2-weighted imaging (fat suppression optional)
	Delayed phase	All contrast agents: Multiphase T1-weighted imaging, preferably using a three dimensional sequence with ≤ 5 mm slice thickness
		Pre-contrast imaging
		Arterial phase (late arterial phase strongly preferred over early arterial phase)
		Portal venous phase
		MRI with extracellular contrast agents or gadobenate dimeglumine
		Delayed phase (2 to 5 minutes after injection)
		MRI with gadoxetate disodium
		Transitional phase (2 to 5 minutes after injection)
		Hepatobiliary phase (about 20 minutes after injection)
Suggested images	Pre-contrast, for initial diagnosis and patients treated with local-regional therapy	Multi-planar acquisition
	Multi-planar reformations	Subtraction imaging
	Thinner slices with section thickness ≤ 3 mm	Diffusion-weighted imaging
		1-3 hours hepatobiliary phase with gadobenate dimeglumine
Dynamic phases	Bolus tracking or fixed timed delay is suggested	Bolus tracking or fixed timed delay is suggested

Technical considerations for computed tomography and magnetic resonance imaging[4,6,10]. CT: Computed tomography; LI-RADS: Liver imaging reporting and data system; MRI: Magnetic resonance imaging.