Estimation of intra-operator variability in perfusion parameter measurements using DCE-US

Table 1 Single straight pipe phantom: intra-operator variability of semi-quantitative perfusion parameters following five 0.02/0.05/0.08 mL bolus injections of SonoVue^®

	PI	TPI	Slope of the WI	FWHM	AUC	AUWI	AUWO
0.02 mL/CV (%)	6.03	9.78	9.57	6.43	9.40	9.97	11.11
0.05 mL/CV (%)	9.27	10.14	8.28	13.24	5.23	12.76	6.84
0.08 mL/CV (%)	20.87	10.10	23.52	17.43	5.87	23.72	2.94

CV: Coefficient of variation; PI: Peak intensity; T_PI: Time to peak intensity; FWHM: Full width at half maximum; AUC: Area under the curve; AUWI: Area under the wash-in; AUWO: Area under the wash-out.

Table 2 Three intertwined pipe phantom: intra-operator variability of semi-quantitative perfusion parameters following five 0.03/0.06 mL bolus injections of SonoVue^®

	PI	TPI	Slope of the WI	FWHM	AUC	AUWI	AUWO
0.03 mL/CV (%)	3.16	7.69	9.65	5.56	2.33	8.55	5.32
0.06 mL/CV (%)	7.85	8.60	11.62	7.53	6.73	9.52	6.12

CV: Coefficient of variation; PI: Peak intensity; T_PI: Time to peak intensity; FWHM: Full width at half maximum; AUC: Area under the curve; AUWI: Area under the wash-in; AUWO: Area under the wash-out.

Table 3 Dialyzer: intra-operator variability of semi-quantitative perfusion parameters following five 0.10 mL bolus injections of SonoVue^®

	PI	TPI	Slope of the WI	FWHM	AUC	AUWI	AUWO
0.10 mL/CV (%)	9.66	8.11	10.27	19.11	9.31	13.89	13.36

CV: Coefficient of variation; PI: Peak intensity; T_PI: Time to peak intensity; FWHM: Full width at half maximum; AUC: Area under the curve; AUWI: Area under the wash-in; AUWO: Area under the wash-out.

Table 4 In vivo studies: intra-operator variability of semi-quantitative perfusion parameters following three 0.02/0.05/0.1 mL bolus injections of SonoVue^®

		Mouse	PI	TPI	Slope of the WI	FWHM	AUC	AUWI	AUWO
0.02 mL/ 0.05 mL/ 0.1 mL/ CV (%)	Chemical anaesthesia	1	18.99	14.04	23.85	28.87	15.79	18.43	15.46
		2	27.60	8.33	25.75	18.90	9.06	28.39	8.12
		3	11.39	4.41	1.48	18.44	10.76	14.73	13.58
		4	27.88	5.68	28.82	29.97	11.21	26.22	12.42
	Gaseous anaesthesia	5	1.90	17.63	10.09	24.96	12.32	12.43	12.79

CV: Coefficient of variation; PI: Peak intensity; T_PI: Time to peak intensity; FWHM: Full width at half maximum; AUC: Area under the curve; AUWI: Area under the wash-in; AUWO: Area under the wash-out.

Table 5 Acoustic properties of different media

	Density (kg/m3)	Velocity (m/s)	Attenuation coefficient (dB/cm at 1 MHz)	Impedance (MRayl)
Blood	1057	1575	0.18	1.61
Water	1000	1480	0.00221	1.51 (50°C)

¹Quadratic frequency dependence of this attenuation coefficient. Sources: Hedrick et al[36], Gupta et al[35], Goldstein et al[37].