| Objective:1. To study the diagnosis value of magnetic resonance Flair high signal blood-vessel sign among patients suffering from cerebral infarction in the blood supply region of middle cerebral artery.2. To discuss the relation between the occurrence rate, rate and distribution of magnetic resonance Flair high signal blood-vessel sign among patients sufferring from cerebral infarction in the blood supply region of middle cerebral artery and basis cranii hemadostenosis and infarct region.Methods:a retrospective analysis was made on the materials of patients that had been diagnosed with "acute cerebral infarction" and had complete clinical and head MRI testing. The magnetic resonance testing included normal MRI plain scanning, DWI, FLAIR, MRA, etc. Eighty-five patients that were not with cerebral infarction in the blood supply region of middle cerebral artery,80 cases with lacunar infarction in the blood supply region of middle cerebral artery,47 cases with proved cardiac source,15 cases with cerebral infarction that were resulted from intracranial tumour or trauma, 20 cases with hemorrhagic cerebral infarction,26 cases with cerebral infarction accompanying by arterial aneurysm, vascular malformation, takayasu arteritis and hematological system diseases, and 15 cases with poor imaging quality that may influence the observation were excluded from this study. The rest 162 cases with cerebral infarction in the blood supply region of midlle cerebral artery were included in this study. According to the length between the occurrence of clinical symptoms and MRI testing,the patients,material was divided into fbur groups: <=24h 33 cases,1-3d62 cases,3-6d 41cases, >6d 26 cases. The general HVS occurrence rate and the occurrence rates of four groups were analyzed and the occurrence rate differences between different groups were compared, yl was used to analyze the relevance between HVS level(1-3 level) and vascular stenosis of the skull base,the relation between HVS occurring and different vascular stenosis level(0-3 level),and the relation between different infarct location and from(cortex,medulla,interspersed,sheet) and HVS level.The relation between different WUlis loop type and HVS occurring were counted and analyzed.Results:1.In the group that is shorter or less than 24 hours, HVS occurred and the positive rate was 81.82%(27/33); in the group of 1-3 days,HVS positive rate 69.35%(43/6^;in l:he group of 3-6 days, HVS positive rate 63.41%(26/41); in the group that is >6 days,HVS positive rate 19.23%(5/26). The statistical analysis indicated that HVS positive rate had no evident statistical difference among groups in 6 days,while HVS positive rate of >6 days group had evident lower positive rate in the MRI bsting(x2=27.587,P〈0.001). So 136 patients that had received MRI testing in 6 days were included in the study for further analysis.2.Different levels of HVS had statistical correlation with hemadostenosis location(P=0.003),2 cases with HVS1 level occurred in internal carotid artery basis cranii stenosis, occupying 6.06%(2/33); 17 cases occurred in M1 section sknosis,22.37%(17/76); 4 cases occurred in M2 section stenosis, 21.05%(4/19); 11 cases with HVS2 level occurred in internal carotid artery basis cranii stenosis, occupying 33.33%(11/33); 13 cases occurred in M1 section stenosis,17.ll%(13/76); 7 cases occurred in M2 section stenosis,36.84%(7/19); 14 cases whh HVS3 level occurred in internal carotid artery basis cranii stenosis, occupying 42.42%(14/33); 22 cases occurred in Mlsection stenosis,28.95%(22/76); 1 case occurred in M2 section stenosis, 5.26%(5/19).3.The relation between different hemadostenosis level and PTVS positive rate;among 136 cases,2 cases with hemadostenosis 0 level,50%(1/2) had HVS; 25 cases with hemadostenosis 1 level,28%(7/25) had HVS; 30 cases with hemadostenosis 2level,53.33%(16/30) had HVS; 79 cases with hemadostenosis 3 level,89.87%(71/79)had HVS. By comparing between any two groups,the HVS occurrence rate of hemadostenosis 1 level, 2 level and 3 level had evident difference(P=0.000), while there was no evident statistical difference between hemadostenosis 1 level and 2 level.4.The relevance between different hemadostenosis location and HVS level: among136 cases, different degree of hemadostenosis occurred to 134 cases(98.53%).Thirty-three cases with internal carotid artery stenosis(ICA), 2 cases with HVS 1 level,11 cases with HVS 2 level, and 14 cases with HVS 3 level; 76 cases with middle cerebral artery Ml section stenosis, 2 cases with HVSl level, 13 cases with HVS2 level and 22 cases with HVS3 level. By statistical analysis,it was fbund that,the relation between internal carotid artery stenosis and HVS occurrence rate and level accompanied by middle cerebral artery stenosis had signincant difference. Patients with stenosis of intracalvarium of internal carotid thnded th have HVS 2 level and 3 level.(X~2=12.927,P<0.001).5.The relation between infarction from distribution and HVS level: 136 cases with cerebral infarction were divide into two forms according to infraction form:intersperthd(n=65) and large region(n=71) distribution. After statistical analysis,it was found that,the occurrence rate of HVS positive among patients with interspersed infarction was 78.46%(51/65),slightly higher than that among patients wkh large region infarction, 63.38%(45/71). Besides, the proportion of HVS 3 levels among patients with inteupersed infarction was significantly higher than that among patients with large region infarction (X~2=12.927,P<0.05).6.The relevance of HVS location and cerebral infarction form: 96 cases wkh HVS positive sign were included in the further study. They weK divided into different groups according to different sections. The statistical analysis indicated that HVS trend in the Ml section was large region involving corticomedullary cerbral infarction,and interspersed cerebral infarction rarely occurred, while HVS trend in M4, 5 section is interspersed small region of cerebral infarction and large region of cerebral infarction rarely occurred. Its cerebral infarction from distribution of HVS in M2,3 section had no evidentstatisticaldifference(P=0.052).7. The percentage of Willis circuit manifesting as type I was 7.4%(10/13,Willis circuit type Ⅱ 58.09%(79/136),Willis circuit type III 2.94%(4/136),Willis circuit type rv 31.62%(43/136) By dividing into complete posterior circulation group and incomplete posterior circulation group, it was found that, the HVS positive rate of the later group was evidently higher than that of the former one(x~2=7.089, P=0.008).Conclusion;1.HVS has high positive rate in the early stage of acute cerebral infarction in the midlle cerebral artery(<6 days),and with time passing by,it has a decreasing trend.2.The distribution and level of HVS are closely related to the vascular stenosis of the skull base: the more serious the proximal part hemadostenosis the degree is, the moire extensive HVS distributes and the higher the level wUl be.3.The distribution of HVS is closely related to the form of cerebral infarction: HVS trend in the Ml section is large region involving corticomedullary cerebral infarction,and HVS trend in M4,5 section is interspersed small region of cerebral infarction.4. Willis circle defect is an important influencing factor of HVS forming. The HVS occurrence rate of wllis posterior circulation defect patients is evidently higher than that with complete posterior circulation. |
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