Imaging Epidemiological Investigation Of Cerebrovascular Diseases And The Prospective Study Of Risk Factors

Part One Imaging epidemiological investigation of Intracranial aneurysms and the prospective study of risk factorsBackgroud: Intracranial aneurysms are one of the most common cerebrovascular diseases,whose incidence is only below infarction and hemorrhage in cerebrovascular diseases. The most common presenting symptom of ruptured intracranial aneurysms is subarachnoid hemorrhage(SAH). Patients who presented with acutely ruptured intracranial aneurysms had 40% associated rate of mortality and about half of the survivors were left with irreversible brain damage. Approximately six to ten in every 100,000 people every year have ruptured intracranial aneurysms.The incidence is difficult to calculate because the unruptured intracranial aneurysms could be symptom-free. According to results of autopsy, the incidence is estimated from 2% to 7.6%. The figure is not precise. At present,According to the domestic and international related reports,the majority study of risk factors of intracranial aneurysms are retrospective, lack of randomized, controlled, prospective studys. Multiple large-scale population (epidemiologic) and randomized study had not been reported before our study.Objective: The purpose of this study is to screen intracranial aneurysms by CE-MRA,which is simple,noninvasive,low expense,and clearly displaying the anatomic of intracranial aneurysms. The incidence and risk factors of intracranial aneurysms will be prospectively studied in Chinese people with suspected cerebrovascular disease in Changhai hospital.,and clinical examination will be carried out appropriately.Methods:We prospectively analyzed the incidence rate and risk factors in about 4000 patients whose age were above 20 years and below 80 years and all of them agreed with informed consent form , accepted biochemical examation and provieded the past history(including subarachnoid hemorrhage, severe headache, ptosis, proptosis, visual field defects, hypertension, diabetes, cerebral hemorrhage, cerebral infarction, brain trauma or surgical history, smoking, drinking, AVM, DAVF history, extracranial aneurysms, intracranial infection history, family history of intracranial aneurysm, hereditary connective tissue disease)before MR examation.MRI and CE-MRA were performed with 1.5T system(Siemens Avanto),using head and neck coils,fluoroscopic triggering technique and three-diemensional fast low angle shot(3D-FLASH)sequence had been used.Scan repeated three times(pre-contrast,arterial phase and venous phase).A 0.2mmol/kg bolus of contrast medium(Gd-DTPA)was injected from antecubital vein at a rate of 3ml/s by a power auto-injector.The source of CE-MRA were subtracted and transferred to computer workstation using 3D reconstruction. Taking intracranial aneurysms as dependent variable, the past history and the results of biochemical examation as independent variables,and processed by SPSS software 18.0. The mainly statistics method including description statistics,chi-square test and Logistic regression.Results:1,Characteristics of the cohort:There were 351 intracranial aneurysm among 3993 patients,and the incidence was 7.8%~8.8%,which was higher than previous reported in the literature, which may be due to different populations.2,Results of mono-variable analysis:Mono-variable analysis showed that the relative factors were related to age,female,cerebral hemorrhage,smoking, infundibular dilation(P<0.05). There are no obvious relationship between intracranial aneurysm and severe headache, ptosis, proptosis, visual field defects, hypertension, diabetes, cerebral infarction, brain trauma or surgical history, drinking, AVM, DAVF history, extracranial aneurysms, intracranial infection history, family history of intracranial aneurysms, hereditary connective tissue disease.The results of biochemical examation(including glucose and lipid) were also independent of intracranial aneurysms.3,Results of muti-variable analysis:Age, female, smoking, cerebral hemorrhage, infundibular dilation were risk factors of intracranial aneurysms. The relative risk (RR) of age was 1.325(95%CI:1.205~1.457);The relative risk (RR) of female was 1.879(95%CI:1.406~2.511); The relative risk (RR) of smoking was 1.288(95%CI:1.064~1.560); The relative risk (RR) of cerebral hemorrhage was 3.233(95%CI:1.265~8.263); The relative risk (RR) of infundibular dilation was 1.431(95%CI 1.016~2.015).4,Others:(1) Both univariate analysis and multivariate analysis showed that age, female, smoking were risk factors for multiple intracranial aneurysms.(2) Intracranial aneurysms often occurred in the carotid artery siphon, not around the Willis ring which was reported in the literature.(3) Intracranial aneurysms in different vessels had different sizes and different rupture incidences.(4) If the aneurysms in the same site of intracranial vessels, the greater the diameter, the higher of the incidence of rupture;However,If the aneurysms in different part of ntracranial vessels,the diameter of aneurysms can not be used to measure the incidence of rupture. Intracranial aneurysms in posterior cerebral circulation,anterior communicating artery were more easier to rupture.Conclusion:Our data from this large,prospective study suggested that:Age, female, smoking, cerebral hemorrhage, infundibular dilation are risk factors of intracranial aneurysms.Part Two The prospective study of risk factors of lacunar infarctionObjective: To study the relationship between lacunar infarction(LI) and various risk factors. Methods:We prospectively analyzed risk factors in about 4000 patients with suspected cerebrovascular disease whose age were above 20 years and below 80 years and all of them agreed with informed consent form , accepted biochemical examation and provieded the past history(including hypertension, diabetes, cerebral hemorrhage, smoking, drinking, intracranial infection history)before MR examation. MRI examinations were performed using conventional sequences on 1.5T system(Siemens Avanto).The diagnosis of cerebral infarction and leukoaraiosis could be available in MRI findings.All of patient were classifiled according to MRI findings:Grade 1~4;NLI/LI;SLI/MLI. Vascular risk factors were studied by univariate and multivariate statistical analysis. Results: Age, hypertension and leukoaraiosis were risk factors of LI. The relative risk (RR) of age was 1.903(95%CI:1.759~2.060);The relative risk (RR) of hypertension was1.613(95%CI 1.362~1.909); The relative risk (RR) of leukoaraiosis was 10.490(95%CI 8.284~13.283). Age, hypertension, diabetes and leukoaraiosis were risk factors of MLI. The relative risk (RR) of age was 1.881(95%CI 1.738~2.037);The relative risk (RR) of hypertension was1.569(95%CI 1.323~1.861); The relative risk (RR) of diabetes was 1.325(95%CI 1.003~1.750 ); The relative risk (RR) of leukoaraiosis was 11.024 ( 95%CI 8.665~14.025).Conclusions:Multiple Logistic regression showed age, hypertension and leukoaraiosis were chief risk factors of LI. Multiple Logistic regression also showed age, hypertension, leukoaraiosis and diabetes were chief risk factors of MLI.Part Three The prospective study of risk factors of leukoaraiosisObjective: To evaluate the correlation between leucoaralosis(LA) and various risk factors. Methods:We prospectively analyzed risk factors in about 4000 patients with suspected cerebrovascular disease whose age were above 20 years and below 80 years and all of them agreed with informed consent form , accepted biochemical examation and provieded the past history(including hypertension, diabetes, cerebral hemorrhage, smoking, drinking, intracranial infection history)before MR examation. MRI examinations were performed using conventional sequences on 1.5T system(Siemens Avanto).The diagnosis of cerebral infarction and lacunar infarction could be available in MRI findings.All of patient were classifiled according to MRI findings:LA/NLA. Vascular risk factors were studied by univariate and multivariate statistical analysis.Results: Univariate analysis showed that age, hypertension, hyperlipidemia, diabetes, cerebral hemorrhage, lacunar infarction, cerebral infarction, hypertriglyceridemia, decreased high density lipoprotein(HDL), increased low density lipoprotein(LDL), hyperglycemia had statistical significance. Multiple Logistic regression showed that age, cerebral infarction, lacunar infarction, cerebral hemorrhage, hypertriglyceridemia were chief risk factors of LA. Conclusions: Univariate analysis and multiple Logistic regression showed that age, cerebral infarction, lacunar infarction, cerebral hemorrhage, hypertriglyceridemia were chief risk factors of LA.Besides these risk factors,the incidence of LA was higher in hypertension, hyperlipidemia, diabetes, dyslipidemia than general population.Part Four Analysis on the anatomic variations of cerebral and cervical vessels by CE-MRA in 4000 CasesObjective:To explore the anatomical variations of the cerebral and cervical vessels by CE-MRA.Methods:4000 patients who had the MRI and CE-MRA images of the cerebral and cervical vessels were selected from al1 the MR images from 2009 to 2010.The normal and variational anatomy of the cerebral and cervical vessels were described.Results:The main variations of the aortic arch were as follows:BCT with LCCA,LSCA,102(5.1%); BCT,LCCA,LVA,LSCA, 63(3.15%);Vagus RSCA originated from BCA,18(0.90%); Dextroaortic arch,3(0.15%). The variation of Willis circle were as follows:Type I occurred in 559 people(14.0%); Typeâ…¡occurred in 2501 people(62.5%); Typeâ…¢occurred in 161 people(4.03%); Typeâ…£occurred in 616 people(15.4%).Trigeminal artery occurred in 16 people(0.4%);Fenestrations occurred in 38 people;Venous malformation occurred in 43 people.Conclusion: The anatomical variations of the cerebral and cervical vessels are relativelycomplicated. It is important to evaluate anatomic variations of cerebral and cervical vessels accurately before clinical diagnosis and treatment.