Table 2. Summary of currently used imaging devices for quantification of hepatic steatosis and fibrosis.

Device	Detection criteria	Accuracy reproducibility quantification	Hepatic volume of assessment	Time accessibility	Cost	Specific comments
Hepatic steatosis
US	Specific sonographic findings [51]	+	+++	+ (bedside)	+	Cannot detect mild steatosis, Observer dependency
CT	liver HU <40 or liver HU−spleen HU <−10 [43]	++	+++	++	++	Radiation hazard
						Diverse criteria for definition (liver/spleen ratio of HU, etc.)
						Low sensitivity in mild steatosis
MRI-PDFF	≥5.6% liver fat [42,44]	+++	+++	+++	+++	Optimal for clinical trials
MRS		+++	+	+++	+++	Gold standard Sampling errors Require expertise/device
CAP by TE	CAP ≥248 dB/m [46] or ≥288 dB/m [47]	++	+	+ (bedside)	+	Not linear in higher liver fat content
						Results are affected by BMI, diabetes, etiology
						XL probe for the obese
Hepatic fibrosis
MRE	Advanced fibrosis (F3) threshold >2.4–5.55 kPa [45]	+++	+++	+++	+++	Diverse cut-points by types of modality (2D, 3D, etc.)
						Most accurate but expensive
						Failure risk in iron overload condition
LSM by TE	Diverse cut-points (7.3–9.9 kPa) for advanced fibrosis (F3) [48,49,50]	++	+	+ (bedside)	+	Affected by BMI (failure risk)
						XL probe for the obese
						TE can measure CAP and LSM simultaneously

US, ultrasonography; CT, computed tomography; HU, Hounsfield unit; MRI-PDFF, magnetic resonance imaging proton density fat fraction; MRS, magnetic resonance spectroscopy; CAP, controlled attenuation parameter; TE, transient elastography; BMI, body mass index; MRE, magnetic resonance elastography; kPa, kilopascals; LSM, liver stiffness measurement; 2D, two dimensional; 3D, three dimensional; CAP, controlled attenuation parameter.