| ObjectiveTo study on 3.0 T diffusion weighted magnetic resonance imaging(Diffusion-weighted imaging,DWI)and perfusion weighted magnetic resonance imaging(Perfusion-weighted imaging,PWI)in the early diagnosis of ischemic stroke,to explore the role of DWI and PWI in judging the location of lesion,the penumbra and the degree of brain injury in the infarct area,comparative study of imaging data and initial imaging treatment of early diagnosed patients after treatment,to evaluate the impact of early diagnosis of DWI and PWI on the prognosis of patients.MethodsTo selected 90 patients with early cerebral infarction neurology department of Xinxiang Central Hospital from January of 2015 to December of 2016 menstrual and conventional MR randomly,all patients signed the informed consent and were able to perform imaging examinations on time.To retrospective analysis of the treatment of newly diagnosed and 15 days after DWI and PWI imaging data.All the data were reviewed by 2 doctors working for imaging diagnosis for many years in our department,and consistent opinions were included in the statistical objects.There were 59 males and 31 females,aged 35～62 years,with an average age of(38.72 ± 19.11)years old in the 90 patients.The onset time was 1～12 hours,39 cases less than 6 hours,51 cases greater than 6 hours less than 12 hours,the average onset time was(6.57 ± 2.96)hours.Check device select GE HDxt3.0 MRI scanner,all patients underwent routine MR,DWI and PWI examinations at first visit and 15 days after treatment,and each quantitative index was measured,such as MTT,ADC,rADC,rCBF,rrCBF,rCBV,rrCBV and so on.To analyze the evolution of lesions on DWI and T2WI,to analyze and compare the vDWI(initial infarct volume),vCBV(initial abnormal CBV volume),vMTT(initial abnormal MTT volume),and vCI(final infarct volume);The MTT,rCBV and ADC values of ROI 1(core infarction),ROI 2(infarct enlargement area),and ROI 3(survival low blood donor area)were measured in all patients with PWI>DWI in early cerebral infarction;ROC(receiver operating characteristic curve)was used to analyze the rMTT,rADC and rrCBV of ROI 15 ROI 2 and ROI 3;The correlation between the degree of mismatch between DWI and PWI and the extent of infarction was analyzed.Used SPSS 19.0 for statistical analysis,the statistical results were expressed by mean standard deviation(x+S),and the difference of P<0.05 was significant.Paired t test was performed to determine the mean ADC in the corresponding areas and lesion sites of the contralateral side;Independent samples t test was performed for rADC,rMTT and rrCBV.Correlation analysis was made between the changes of mean rADC value,infarct volume and time after initial and reexamination.The core of the infarction,DWI initial examination of the abnormal CBV,the volume of MTT and review the corresponding examination results do not match the degree and extent of infarct size by correlation analysis.ResultsAll of the 90 patients with PWI and DWI showed all ischemic lesions.There were 12 patients normal on T2WI of the 39 patients with cerebral infarction.The 90 patients showed high signal on DWI,and the ADC value decreased significantly compared with the corresponding area of the contral side.The average ADC value and the contral corresponding average ADC values by the paired t test,there was significant difference(t=16.13,p<0.001),and with the extension of time,the rADC value gradually from low to high,returned to normal on the 15 day follow-up imaging examination basically.The signals of ADC in DWI were different at different stages of the lesions,and the gradient appeared.The correlation between rADC and time was statistically significant(r = 0.542,p<0.001).In the 90 patients,83patients showed increased MTT and decreased rCBV,and 4 patients had MTT decrease and rCBV increase.The mean MTT value of the affected side and the mean value of rrCBV were significantly different from those of the contral side(t ＝6.28,p<0.001).After 15 days of treatment,the vDWI for(61.5 ±71.4)cm3,more than vCI(38.2±46.1)cm3,there was significant difference between them(p<0.001);vMTT for(124.1±59.2)cm3.There was significant higher than that of vCBV(59.6 ± 57.3)cm3,there was significant difference between them(p<0.001);vCBV greater than vDWI(DWI)abnormal volume)(32.6 + 48.5)cm3,there was significant difference between them(p<0.001).All of the 90 patients,there were 9 cases of patients with vCI and vMTT roughly equivalent,61 cases of patients with vCI less than vMTT,20 cases of patients with vCI more than vMTT.The vCI and vMTT and vCI and vDWI,vCI and vCBV were analyzed by Spearman correlation analysis,the results showed that the correlation coefficients of the three were 0.701,0.925 and 0.938,respectively,and the P values were all<0.001.The results showed that vCI had the lowest correlation with vMTT,and had the highest correlation with vCBV.The threshold values of rMTT,rADC and rrCBV were 127.3%,90.1%and 83.9%respectively in the 90 patients who had undergone ischemic tissue examination for the first time.ROI1,ROI2,ROI 3 of rMTT were 174.2%,142.2%,115.7%,there was significant difference between groups(p<0.001),rMTT>survived low blood supply area in the enlarged area of core infarction and infarction area.The average rADC values were 56.9%,89.8%,95.7%,there was significant difference between groups(p<0.001),The rADC value of the focal infarction area<infarction enlargement area<survival low blood supply area;the rrCBV were 26.7%,67.9%,96.3%,the rrCBV value of compared with the focal infarction area<infarction enlargement area<survival low blood supply area.There was significant difference between groups(p<0.001,rrCBV).And all of the 90 patients before and after treatment of NIHSS comparison,after treatment than before significantly decreased,the difference was statistically significant(p<0.01).ConclusionsDWI and PWI are highly sensitive to hyperacute cerebral infarction and acute cerebral infarction,and can make rapid and accurate diagnosis to guide the clinical treatment.It is convenient for patients to follow up,and provides safe,convenient and accurate imaging basis for evaluating therapeutic effect.The change of lesion site ADC is beneficial to the judgement of PWI-DWI’s mismatch,and the evolution rule of ADC value can judge the stage of cerebral infarction.The measurement results of ADC,MTT and rCBV ratio have guiding significance for the change of infarct size and the risk degree of ischemic tissue. |
