TABLE 2:

Difference in CCA Doppler parameters between patients with and without each intracranial collateral

Side-to-side ratio	ACoA		PCoA		OA		LM
Side-to-side ratio	(56/25)	P	(19/62)	P	(21/60)	P	(14/67)	P
PSV	1.32 ± 0.43	NS	1.30 ± 0.30	NS	1.38 ± 0.38	NS	1.40 ± 0.42	NS
	1.17 ± 0.37		1.27 ± 0.45		1.24 ± 0.42		1.25 ± 0.41
EDV	1.63 ± 0.59	.0005	1.81 ± 0.65	.004	2.00 ± 0.66	<.0001	1.88 ± 0.84	.004
	1.18 ± 0.29		1.39 ± 0.49		1.31 ± 0.39		1.41 ± 0.45
TMV	1.47 ± 0.52	.009	1.57 ± 0.57	.05	1.64 ± 0.44	.003	1.51 ± 0.51	NS
	1.18 ± 0.28		1.33 ± 0.43		1.29 ± 0.45		1.36 ± 0.47
PI	0.90 ± 0.28	NS	0.88 ± 0.30	NS	0.91 ± 0.32	NS	0.97 ± 0.29	NS
	1.00 ± 0.22		0.95 ± 0.25		0.94 ± 0.24		0.92 ± 0.26
RI	0.95 ± 0.11	.01	0.95 ± 0.12	NS	0.95 ± 0.13	NS	0.95 ± 0.13	NS
	1.01 ± 0.08		0.97 ± 0.10		0.97 ± 0.09		0.97 ± 0.09

Note.—ACoA indicates anterior communicating artery; PCoA, posterior communicating artery; OA, ophthalmic artery; and LM, leptomeningeal collateral. The number in parenthesis indicates the number of the patients with/without each collateral. The side-to-side ratios of Doppler parameters are described in the Table. Upper and lower columns indicate the ratio in patients with and without the collaterals, respectively; P value under .05 is considered to be significant; and NS represents not significant.