Affected Factors Analysis On FLAIR Vascular Hyperintensities In Ischemic Cerebrovascular Diseases

Purpose: to explore occurrence regularity and affected factors of the T2 FLAIR vascular hyperintensity sign(FVH) by retrospective measuring and analyzing cerebral conventional MRI, DWI, MRA images in patients with ischemical cerebrovascular disease.Materials and methods: One hundred and twenty patients suspected with ischemic cerebrovascular disease were collected from July 2014 to September 2014 by using the picture archiving and communication system(PACS), including 83 male cases, 37 female cases, mean age was 68.02±11.62 years. All patients underwent head MR scan including cross-sectional T2 WI, T2 FLAIR, T1 FLAIR, DWI and 3D TOF MRA. A senior attending physician observed and measured these images, recorded all changes: FVH, the degree of vascular stenosis of liability side, Classification of leukoaraiosis, the stage of cerebral infarction(recent infarction, old cerebral infarction) and ASPECT score; collected the baseline clinical data of patients with age, sex, blood pressure, fasting blood glucose, serum total cholesterol, triglyceride, NIHSS score, the course of the disease(time from attack to MRI scan), thrombolysis or not, history. Data was statistically analyzed with SPSS 17.0 software package. Chi square test was used to compare the FVH difference between patient groups according vascular stenosis(none, mild to moderate, severe stenosis), infarction stage(recent infarction, old cerebral infarction), age(≥ 70 years old, <70 years old); Rank sum test was used to detect NIHSS and ASPECT score differences between patient groups with and without FVH; Logistic regression analysis was used to detect the correlation between clinical data including age, course of disease, hypertension, blood glucose, serum total cholesterol, triglyceride, vascular stenosis, the degree of leukoaraiosis and FVH in 110 patients. P <0.05 was deemed as showing statistical significance.Result:1、FVH occurrence rate: 60.8%(73/120)cases with ischemic cerebrovascular disease showed FVH.2 、 FVH occurrence rate in various groups according vascular stenosis: In various groups that showed none, mild to moderate and severe vascular stenosis of liability side, the FVH occurrence rate were 44%( 22/50), 71.5%(33/46) and 75%(18/24), respectively, and showed significant difference(P<0.05). Logistic regression analysis also confirmed the definite correlation between vascular stenosis of the liability side and FVH(P < 0.05).3、FVH occurrence rate in various groups according cerebral infarction stage: FVH occurrence rate in patients with recent infarction was higher than that with old infarction(76.6%, 51.9%, P<0.05).4、Difference in cerebral infarction range between patients with and without FVH: No significant difference was found between the ASPECT score of patients with and without FVH(Z=-0.372, P=0.71). It is suggested that FVH cannot reflected infarct area.5、Correlation between FVH and leukoaraiosis(LA): In all patients, no LA accounted for 50%( 6/12), grade 1 for 42.5%( 17/40), grade 2 for 62.5%(25/40), grade 3 for 89.3%(25/28). Logistic regression analysis showed that LA was the affected factor for FVH(P < 0.05).The heavier LA is, the higher the occurrence rate of FVH appears.6、Correlation between FVH and NIHSS score: In 29 patients with NIHSS score data, no significant difference was found between patients with and without FVH(Z=0.056, P=0.956).7、 Correlation between FVH and clinical data: Logistic regression analysis showed that fasting blood glucose was the most meaningful affected factor of FVH(P=0.027), that is the higher the blood glucose is, the higher the occurrence rate of FVH appears. No obvious correlation was found between FVH and patient age, course of disease, blood pressure, serum triglyceride, serum total cholesterol(P>0.05). But obvious difference(P=0.035) was found between groups divided by age(≥ 70 and <70). FVH occurrence rate in patients older(including) than 70 years old was 71.4%(40/56). FVH occurrence rate in patients younger than 70 years old was 51.9%(28/54).Conclusion:1 、 FVH is a common sign in ischemic cerebrovascular disease caused by intracranial artery stenosis, and correlate with vascular stenosis degree. The severer the stenosis degree is, the higher the occurrence rate of FVH appears.2、Occurrence rate of FVH was increased significantly in patients with recent infarction, while, no obvious correlation was found between it and the size of infarction.3、Advanced age(>70 years old) and hyperglycemia were significant affected factors of FVH(P<0.05).