TABLE 3.

Mean (SD) of US parameters among cases/controls and by NVC groups; P values for US parameters differences among NVC groups and between cases and controls. Cases showed higher resistive index (P = .0115) and slower systolic velocity at the level of the second interdigital artery (P = .005)

	Cases N = 33	VCS = 0 n = 7 (21%)	VCS = 1 n = 4 (12%)	VCS = 2 n = 14 (42%)	VCS = 3 n = 8 (24%)	Controls n = 34	VCS classes	Cases vs controls
	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)	P value	P value
dRI	0.65 (0.14) n = 26	0.67 (0.11) n = 6	0.83 (0.22) n = 2	0.64 (0.14) n = 13	0.59 (0.14) n = 5	0.57 (0.11) n = 33	.2540	.0115
pRI	0.76 (0.11) n = 32	0.73 (0.11) n = 7	0.72 (0.07) n = 4	0.76 (0.09) n = 14	0.81 (0.14) n = 7	0.73 (0.12) n = 34	.5354	.3596
PV, cm/s	8.38 (3.00) n = 32	7.30 (2.57) n = 7	8.51 (4.03) n = 4	9.00 (3.36) n = 14	8.16 (2.20) n = 7	11.14 (4.50) n = 34	.6868	.0050

Abbreviations: VCS, videocapillaroscopy; SD, standard deviation; dRI, distal resistive index; pRI, proximal resistive index; PV, peak velocity.