The Relationship Between Vertebral Artery Hypoplasia Complicated With Fetal Posterior Cerebral Artery And Cerebellar Infarction

Objective:The objective was to evaluate the relationship between vertebral artery hypoplasia complicated with fetal posterior cerebral artery and cerebellar infarction using magnetic resonance angiography (MRA).Materials and Methods:We had retrospectively analyzed the baseline data and imaging data of the consecutive cases who have been diagnosed with acute cerebral infarction between January 1,2011 and December 31,2014. All patients were scanned with a 3T scanner using 16 channel head coil (Achieva X-Series, Philips Healthcare, Best, the Netherlands). Three dimensional (3D) time of flight (TOF) MRA imaging of cross section was preformed using 3D fast field echo sequence and multichunk technique from the aortic arch to the Willis ring in three segments. The images were reconstructed by maximum intensity projection (MIP) to obtain 3D displays and assembled using the Mobiview Philips software to reconstruct the continuous images from the aortic arch to the Willis ring. All the patients have underwent MRA of head and neck and cerebral magnetic resonance imaging (MR1) at 3T MRI system. According to the development of vertebral artery and fetal posterior cerebral artery, the patients were divided into four groups:control group (bilateral vertebral arteries and posterior cerebral arteries were normal, vertebral artery hypoplasia (VAH) group, VAH complicated with fetal posterior cerebral artery (FPCA) group and FPCA group. The numbers and locations of cerebellar infarction in each group were recorded, and then the incidences of cerebellar infarction between different groups were compared. The relationship between the sides of vertebral artery hypoplasia and cerebellar infarction was also analyzed.Results:4070 patients were included in this study ultimately. Among them 2732 were male and 1338 were female, aged from 31 to 87 years, with an average of 62.81±10.67 years. There were 536 (13.17%) cases of vertebral artery hypoplasia,323 (7.94%) cases occurred on the right side,190 (4.67%) cases occurred on the left side and 23(0.56%) cases occurred on both sides. There were 869 (21.35%) cases of fetal posterior cerebral artery,382 (9.39%) cases occurred on the right side,277 (6.80%) cases occurred on the left side and 210 (5.16%) cases occurred on both sides. The incidence of fetal posterior cerebral artery in patients with vertebral artery hypoplasia was 49.44% compared to 17.09% of patients without vertebral artery hypoplasia. This difference was significant (P<0.05).There were 2930 cases in control group,271 cases in VAH group,265 cases in VAH complicated with FPCA group and 604 cases in FPCA group. There were no statistical differences in cerebrovascular diseases’risk factors between different groups (P<0.05).195(4.79%) cases of unilateral cerebellar infarction were found. The incidences of cerebellar infarction from low to high were 3.28% of control group, 4.14% of FPCA group,10.94% of VAH complicated with FPCA group,16.61% of VAH group. The incidences of unilateral cerebellar infarction of four groups were significantly different (P<0.05). After pairwise comparison, the differences were statistically significant (P<0.05) of VAH group/FPCA group, VAH group/control group, VAH complicated with FPCA group/FPCA group, VAH complicated with FPCA group/control group, however, the differences were not statistically significant (P>0.05) of VAH group/VAH complicated with FPCA group, FPCA group/control group.45 cases in VAH group occurred unilateral cerebellar infarction,39 cases occurred on the same side of vertebral artery hypoplasia and 6 cases occurred on the contralateral side.2 cases occurred unilateral cerebellar infarction in bilateral VAH with bilateral FPCA.13 cases occurred unilateral cerebellar infarction in VAH accompanied with ipsilateral FPCA group, of which 7 cases occurred on the same side of vertebral artery hypoplasia and 6 cases occurred on the contralateral side.10 cases occurred unilateral cerebellar infarction in VAH accompanied with contralateral FPCA group, of which 8 cases occurred on the same side of vertebral artery hypoplasia and 2 cases occurred on the contralateral side.4 cases occurred unilateral cerebellar infarction in VAH accompanied with bilateral FPCA group and all occurred on the same side of vertebral artery hypoplasia. The incidence of unilateral cerebellar infarction on the same side of vertebral artery hypoplasia was 80.56% compared to 19.44% on the opposite side. This difference was significant (P<0.05).Conclusion:There is a correlation between vertebral artery hypoplasia complicated with fetal posterior cerebral artery and cerebellar infarction and no correlation between fetal posterior cerebral artery and cerebellar infarction. Cerebellar infarction is usually observed on the same side of vertebral artery hypoplasia.