OBJECTIVE: To determine the imaging characteristics of basilar @entity432 (BAH). METHODS: From October 2009 to August 2013, 10 193 magnetic resonance angiogram (MRA) and 31 716 magnetic resonance imaging (MRI) consecutive cases were retrospectively retrieved from our institutional Picture Archiving and Communication System (PACS) database. BAH was defined as a continuous diameter reduction all over artery and a basilar artery diameter  <= 2 mm. The same cut-off value was applied for @entity5525 ( @entity5525 ). We measured the diameters of basilar and vertebral arteries with PACS in all @entity1 according to source imaging and IMP construction of MRA. The carotid arterial computed tomography angiogram (CTA) profiles were reviewed in 50 @entity1 . The fetal-type posterior circle of Willis (FTP) was assessed. The diagnosis of @entity385 was based on clinical symptoms, signs and a high signal on diffusion-weighted imaging (DWI). Acute @entity385 was divided into anterior circulation @entity64 (ACS) and posterior circulation @entity64 (PCS). RESULTS: A total of 210 BAH were identified among 10 193 consecutive @entity1 . BAH was more common in females (56.7%) than males (43.3%) in the @entity1 group. They had a fetal-type of posterior cerebral artery (FTP) (175 bilateral (83.3%), 35 unilateral (16.7%)). 99.5% @entity1 had V4 @entity5525 and 56.0% (28/50) V1-V3 @entity5525 . Among 210 BAH, there are 74 @entity1 (mean age 64 years, average 25-91 years, 44 males) with a diagnosis of @entity385 ( @entity385 ). The males were predominant in @entity385 (59.5% in males vs 40.5% in females, P = 0.021). The frequency of BAH was detected in 74 (2.2%) among 3 294 @entity385 @entity1 . CONCLUSION: As a relatively rare @entity455 , BAH has always unilateral or bilateral FTP and V4 @entity5525 .

[Imaging characteristics of basilar XXXX ].

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity5525 :: ('MESH:C538664', 'Disease') :: ['vertebral artery hypoplasia', 'VAH'] @entity64 :: ('MESH:D020521', 'Disease') :: ['stroke'] @entity455 :: ('MESH:D014652', 'Disease') :: ['vascular abnormality'] @entity432 :: ('MESH:D001157', 'Disease') :: ['artery hypoplasia'] @entity385 :: ('MESH:D002544', 'Disease') :: ['ACI', 'acute cerebral infarction', 'cerebral infarction']
@entity432 :: (MESH:D001157,Disease) :: ['artery hypoplasia']
