CTA Characteristics of the Circle of Willis and Intracranial Aneurysm in a Chinese Crowd with Family History of Stroke

Table 2

Anatomical variations in the anterior Circle of Willis.

	Participant,	Normal circle, (%)	Prevalence of variants,									Incomplete proportion, (%)
			Incomplete						Complete		Total of variants
			Male	153	93 (60.8)	5	4	1	4	43	1^†		2	0	60	58 (37.9)
Female	128	63 (49.2)	1	11	2	10	39	0	1	1	65	63 (49.2)
Total	281	156 (55.5)	6	15	3	14	82	1	3	1	125	121 (43.1)
value												0.057

† indicates that the variation includes undesirable variation of right A1 segment.