New ultrasound techniques for lymph node evaluation

Table 1 Criteria on lymph node characterization using different ultrasound modes

Lymphadenopathy more (most) likely	B-mode	(Contrast enhanced) Colour Doppler	Vascular resistance	CEUS (contrast special imaging mode)	Elastography
Inflammatory	Preserved architectur, homogeneous, thin cortex	Preserved vessel architecture, hilar vascularity with or without tree like branching.	Lower, RI < 0.8, PI < 1.6	Homogeneous enhancement from the hilum, centrifugal enhancement	No data, most often normal architecture (except tuberculosis)
Malignant infiltration (metastasis)	Destroyed architecture (capsule), eccentric hypoechoic cortical thickening,	Peripheral or mixed vascularity, inhomogeneous vessel density, split arteries, torturous course of vessels	Higher, RI > 0.8, PI > 1.6, often variableat different sites	Centripetal enhancement, different intra-nodal enhancement levels, inhomogeneous wash-out, perfusion defects	Initially circumscribed. SR in diffuse infiltration > 1.5 (1.78)
	inhomogeneity of the internal structure, loss of echogenic hilum, surrounding edema
Lymphoma	Focal or global hypoechoic cortical thickening, usually without echogenic hilum, peri-nodular edema, pseudocystic appearance	Often but not always preserved vessel architecture, rich vascularity	Intermediate RI and PI	Intense homogeneous enhancement, starts with diffuse bright spots, peripheral hypo-or non-enhancement	No data; wide range of appearance applying qualitative criteria

CEUS: Contrast enhanced ultrasound; RI: Resistive index; PI: Pulsatility index.