Table 2.

Feature classification and diagnostic performance of quantitative ultrasound features by different users.

		Thickness	Thickness Variation	PID	Nonlinearity	Tortuosity	Echo Intensity	Echo Heterogeneity	Overall Performance (AUC)
User 1	COVID-19	5.20	0.23	2.68	0.25	1.54	186.86	18.45	0.96
	Normal	1.80	0.06	0.70	0.81	1.04	195.06	14.69
	p-value	0.04	0.04	0.01	0.01	0.01	0.47	0.12
User 2	COVID-19	4.62	1.97	2.45	0.20	1.46	184.79	20.96	0.98
	Normal	1.41	0.36	0.49	0.90	1.01	197.41	18.60
	p-value	0.00	0.00	0.00	0.00	0.00	0.30	0.43
User 3	COVID-19	6.03	0.25	2.45	0.23	1.33	129.20	34.46	0.92
	Normal	2.51	0.06	0.59	0.74	1.08	137.74	32.38
	p-value	0.03	0.00	0.00	0.00	0.07	0.20	0.53
User 4	COVID-19	4.69	0.67	1.62	0.23	1.51	202.21	13.91	0.84
	Normal	1.10	0.85	1.84	0.79	1.16	212.31	11.50
	p-value	0.00	0.69	0.84	0.04	0.02	0.51	0.06
User 5	COVID-19	5.84	1.40	3.03	0.13	1.10	167.21	34.62	0.99
	Normal	2.16	0.44	0.93	0.78	1.04	182.48	27.56
	p-value	0.00	0.01	0.01	0.00	0.04	0.22	0.04