Affecting Factors Of Prominent Vessel Sign On Magnetic Susceptibility Weighted Imaging In Acute Ischemic Stroke And Its Value Of Assessment On Short-term Prognosis

Objective: To study the influencing factors of prominent vessel sign(PVS)on susceptibility weighted imaging(SWI)in patients with acute ischemic stroke(AIS),and to explore the clinical value of PVS in evaluating the short-term prognosis of AIS patients.Materials and Methods: 82 patients with acute ischemic stroke were collected within 72 hours from onset to MRI examination.The conventional MRI sequence,FLAIR,MRA,DWI,SWI were performed.Some of the patients underwent arterial spin labeling imaging(ASL)at the same time.The National Institutes of Health Stroke Scale(NIHSS)was evaluated by a neurologist at admission and 15 days later.PVS was defined as a low signal vessel with a significant increase in the number of vessels and/or a marked increase in the diameter of the vessels in the blood supply area of the responsible vessel and around the infarct area.By observing and comparing the low signal vessel in theblood supply area of the responsible vessel on SWI-minIP image and the normal position of the opposite side,we can judge whether the patients have PVS or not,and divide the patients into PVS positive group and PVS negative group.The general clinical data,degree of stenosis of responsible vessels and infarct size of the two groups were compared by independent sample t-test,Mann-Whitney U test,chi-square test and Fisher's exact test.Bonferroni method was used for further comparisons when there was statistical significance in the composition ratio of multiple groups.According to the treatment methods adopted by patients,the Patients were divided into special treatment group and general treatment group.After MRI examination,patients in the special treatment group were treated with thrombolysis or mechanical thrombectomy,,while patients in the general treatment group were only treated with conservative treatment.After15 days of onset,the clinical efficacy was assessed by neurological function score reduction rate.According to the literature,the evaluation criteria were divided into two grades: marked effect(NIHSS score decreased by more than46%)and efficacy difference(NIHSS score decreased by less than 45%).The treatment effect and NIHSS score of PVS positive and PVS negative patients after 15 days of onset were compared by statistics.Results:(1)Of 82 patients with acute ischemic stroke,45 were PVS positive and 37 were PVS negative.There was no significant difference in age,sex composition,systolic blood pressure,diastolic blood pressure,hypertension,hyperlipidemia,diabetes mellitus and atrial fibrillation between the two groups(P > 0.05).Compared with the PVS negative group,the patients with PVS positive group had higher NIHSS score at admission,more serious stenosis of responsible vessels and larger infarction area.the NIHSS score of the PVS positive group was higher,the degree of responsible vessel stenosis was moreserious,the infarction area was larger,and the difference was statistically significant(P < 0.05).PVS positive was more common in patients with large-artery atherosclerotic cerebral infarction,while PVS negative was more common in patients with small artery occlusive cerebral infarction,and the difference was significant.(P < 0.0083);(2)26 patients in the special treatment group in this study.Among them,there were 15 cases in PVS positive group and11 cases in PVS negative group.After 15 days of onset,there was no significant difference in the treatment effect between the two groups(P>0.05),but the NIHSS score of PVS negative group was significantly lower than that of PVS positive group(P<0.05);56 cases in the general treatment group.Among them,there were 30 cases in PVS positive group and 26 cases in PVS negative group.After 15 days of onset,there was significant difference in the therapeutic effect between the two groups(P<0.05),and the NIHSS score of PVS positive group was significantly higher than that of PVS negative group(P<0.05).Conclusion:1.The patients with acute ischemic stroke had high NIHSS score at admission,the degree of stenosis of responsible vessels is serious,the extent of involvement of lesions is large,and the probability of positive PVS is high,which is more common in large-artery atherosclerotic cerebral infarction;2.The neurological deficits of PVS positive patients were more serious than those of PVS negative patients,and the short-term prognosis is poor.PVS is an imaging marker of poor prognosis in patients with acute ischemic stroke.