Ultrasound elastographic techniques in focal liver lesions

Table 1 Studies reporting the cut-off value and relative sensitivity, specificity, likelihood positive ratio and likelihood negative ratio for different elastographic techniques in the differential diagnosis of benign vs malignant focal liver lesions

Ref.	Method	Study design	Cut-off1	Sens (%)	Spec (%)	LR (+ve)	LR (-ve)	Level of evidence2
Park et al[28], 2013	ARFI	Prospective,	1.82	71.8	75	2.9	0.38	4
	(m/s)	monocentric
Sandulescu et al[33], 2012	RTE	Retrospective,	170	92.5	89	8.3	0.08	4
	Hue	monocentric
Guo et al[30], 2015	ARFI-SWV	Prospective,	2.13	83.3	78	3.7	0.20	4
	(m/s)	monocentric	(ratio 1.37)	(ratio 59.6)	(ratio 77.3)	(ratio 2.6)	(ratio 0.5)
Ronot et al[32], 2015	ARFI	Prospective,	-	-	-	-	-	4
	(m/s)	Monocentric
Zhang et al[31], 2013	ARFI-VTTQ	Retrospective,	2.22	81.3	93	11.1	0.20	4
	(m/s)	monocentric

¹To differentiate malignant from benign liver lesions;

²http://www.cebm.net/oxford-centre-evidence-based-medicine-levels-evidence-march-2009. ARFI: Acoustic radiation force imaging; RTE: Real time elastography; HCC: Hepatocellular carcinoma; FNH: Focal nodal hyperplasia; SWE: Share wave elastography; SWV: Shear wave velocity; VTTQ: Virtual touch tissue quantification.

Table 2 Summary of the Sonoelastographic techniques and the studies that investigate their role in the assessment of focal liver lesions

Type of elastography	Elastographic method	Commercial implementation	Studies investigating the role of elastography in FLL
Strain	RTE	Hitachi 6500®	Sandulescu et al[33] 2012
		LOGIQ E9, GE®	Wiggermann et al[34] 2013
		Acuson 128XP®	Varghese et al[35]
Dynamic	TE	Echosens®	Masuzaki et al[36] 2009
			Jung et al[37] 2011
			Singh et al[38] 2013
			Akima et al[39] 2011
			Fernández-Montero et al[40] 2013
			Fung et al[41] 2011
			Chon et al[42] 2013
			Merchante et al[43] 2012
			Salmon et al[44] 2012
			Calvaruso et al[45] 2012
			Narita et al[46] 2012
			Feier et al[47] 2013
	ARFI and SWEI	Acuson S2000 Siemens®	Park et al[28] 2013
		Aixplorer SuperSonic Imagine®	Gallotti et al[29] 2012
			Guo et al[30] 2015
			Zhang et al[31] 2013
			Ronot et al[32] 2015
	VA		None available

RTE: Real-time ultrasound elastography; TE: Transient elastography; ARFI: Acoustic radiation force impulse; SWEI: Share wave elasticity imaging; VA: Vibro-acoustography.