Cerebral Diffusion-weighted Imaging And Risk Factors Analysis For Patients With Carotid Stenosis

Objective: To investigate the alterations of subtle cerebral structures caused bycarotid stenosis, and to determine the stenosis-related risk factors by usingdiffusion-weighted imaging and MR angiography.Methods:116cases of carotid stenosis (61males,55females, age range:38-89yearsold, mean age:65.22±11.53years old) and21cases of matched healthy controls (9males,12females, age range:39-80years old, mean age:61.76±10.63years old) were recruitedin this study on the basis of three-dimensional contrast enhanced MR angiography (MRA)of carotid artery. The degree of carotid stenosis was graded as mild, moderate, and severestenosis according to the classification of North American Symptomatic CarotidEndarterectomy Collaborative Group. Patients with carotid occlusion were classified intothe severe stenosis subgroup. ADC values of interested regions were measured on DWI(b=0,1000s/mm2) images. This research comprised three parts:（1）On the basis of patient,116patients were graded as47cases of mild stenosis,29cases of moderate stenosis, and12cases of severe stenosis according to the severer side.（2）On the basis of carotid artery,274carotid arteries were graded as114arteries of mild stenosis,36arteries of moderate stenosis,21arteries of severe stenosis, and103arteries of normal appearance（.3）The clinical data ofall subjects were collected, which included gender, age, history of hypertension, diabetesmellitus, hypercholesterolemia, hypertriglyceridemia, smoking, and alcohol abuse. Logisticregression analysis was conducted for the determination of stenosis-related risk factors forcarotid stenosis. P＜0.05is of statistical significance.Results:1. To compare with bilateral cerebral ADC values of stenosis groupsdivided by the degree of the heavier side, excluding bilateral stenosis and contralateralmoderate stenosis cases,there are significant differences in the mild group with the ADCvalues of caudate nucleus head (P＜0.05). The ADC values of moderate group aroundanterior and posterior horn of lateral ventricle and the ADC values of periventricular anterior and posterior、 temporal occipital junction area and temporal lobe havesignificant differences (P＜0.05). Whereas, there are significant differences with theADC values of severe group both around anterior and posterior horn of lateral ventricleand the ADC values of periventricular anterior and posterior、the caudate nucleus head、temporal occipital and frontotemporal junction regions(P＜0.05). Over all, The ADCvalues around anterior and posterior horn of lateral ventricle and the ADC values ofperiventricular anterior and posterior、temporal occipital junction regions with normaland mild groups are significantly higher than moderate and severe groups。2.The ADC values around anterior(r=0.194, P=0.001) and posterior horn (r=0.188, P=0.002)of lateral ventricle and the ADC values of periventricular anterior（r=0.260，P=0.000）and posterior(r=0.149, P=0.014)、the temporal lobe (r=0.186,P=0.002)and the caudate nucleus head (r=0.125, P=0.039) have positively linearlycorrelate with the degree of stenosis with274branches of carotid arteries.In which,theADC values of periventricular anterior is most closely related to the carotid stenosisdegree. All the groups and interested regions are compared with the ratio of ADC valueswith stenosis and volunteer group,and the ADC values around periventricular anteriorare significantly ratio in mild group and severe group.3.In this study,116cases of stenosis groups included27for diabetes,64forhypertriglyceridemia,49for hypercholesterolemia,61of male, female55cases,91for60years old or even more,21for hypertension I,22for hypertensionII,25forhypertensionIII,14for smokers and6for alcoholics.The result of logistic regressionanalysis showed that diabetes, hypertriglyceridemia, hypercholesterolemia,male, age≥60-year-old are independent risk factors for carotid stenosis (P＜0.05).Conclusion:1. The presence and severeness of carotid stenosis can be intuitivelyreflected through combination of MRA and DWI, which could also give an accurateevaluation for the alterations of subtle structures within white matter.2.ADC values in the majority of cerebral regions positively correlated with thesevereness of carotid stenosis. Especially, ADC values of periventricular anterior wasmost closely related to the carotid stenosis, which is most sensitive for hypoperfusion.3. Diabetes, hypertriglyceridemia, hypercholesterolemia, gender and age are allindependent risk factors for carotid stenosis.