Imaging features and management of focal liver lesions

Table 2 Variants of incidental liver lesions and recommended appropriate imaging recommended by American College of Radiology

Variants	Initial imaging	Size	Extrahepatic malignancy	Underlying chronic liver disease	Appropriate imaging
Variant 1	US	> 1 cm	No	No	US abdomen with IV contrast
					MRI abdomen without and with IV contrast
					CT abdomen with IV contrast multiphase
Variant 2	CT (non-contrast or single-phase)	> 1 cm	No	No	MRI abdomen without and with IV contrast
	MRI (non-contrast)				CT abdomen with IV contrast multiphase
Variant 3	US	> 1 cm	Yes	No	MRI abdomen without and with IV contrast
					CT abdomen with IV contrast multiphase
Variant 4	CT (non-contrast or single-phase)	> 1 cm	Yes	No	MRI abdomen without and with IV contrast
	MRI (non-contrast)				CT abdomen with IV contrast multiphase
					FDG-PET/CT skull base to mid-thigh
Variant 5	US	> 1 cm	No	Yes	US abdomen with IV contrast
	CT (non-contrast or single-phase)				MRI abdomen without and with IV contrast
	MRI (non-contrast)				CT abdomen with IV contrast multiphase
Variant 6	US	< 1 cm	Yes	No	MRI abdomen without and with IV contrast
Variant 7	CT (non-contrast or single-phase)	< 1 cm	Yes	No	MRI abdomen without and with IV contrast
	MRI (non-contrast)				CT abdomen with IV contrast multiphase
Variant 8	US	< 1 cm	No	Yes	MRI abdomen without and with IV contrast
	CT (non-contrast or single-phase)				CT abdomen with IV contrast multiphase
	MRI (non-contrast)

Variants of incidental liver lesions and recommended appropriate imaging recommended by American College of Radiology[9]. ACR: The American College of Radiology; CT: Computed tomography; IV: Intravenous; MRI: Magnetic resonance imaging; US: Ultrasound; FDG-PET: Fluorodeoxyglucose positron emission tomography.