The Research Of Acute Cerebral Infarction By Means Of Fast Diffusion Kurtosis Imaging Of Magnetic Resonance

Objective To investigate the clinical value of fast diffusion kurtosis imaging(fast DKI) in patient with acute ischemic stroke; To investigate the evolution of mean kurtosis(MK) MK and mean diffusivity(MD) value in patients with acute ischemic stroke by fast DKI; To investigate the correlation between the lesion value and volume of MK in acute stage and the clinical outcome.Methods Thirty patients with acute cerebral infarction were selected as the patient group, including male 18 cases, female 12 cases, age 41-79 years, average 61.2±8.2 years. These patients were performed MRI scans(3T, Trio, Siemens) within 12 hours and 7 days. There were 11 cases were scanned five times after the stroke onset(within 12 hours, 7 days, 1 month, 3 months, 6 months), male 8 cases, female 3 cases, aged 50-76 years, average 61.2±7.8 years. Twenty healthy volunteers were selected as the control group, and the gender and the age were matched with patient group. The healthy volunteers include males 12 cases, female 8 cases, aged 51-69 years, average 60.0±4.2 year. All patients were performed independently by two experienced neurological doctors before each examination. The National Institutes of Health Stroke Scale(NIHSS) was performed within 12 hours, 7 days, and one month. Barthel index(BI) and modified Rankin Scale(m RS) were assessed after one month, three months and six months. The lesions and the contralateral tissue were measured by two experienced radiologists using MRIcron software. The evolution of MK and MD values in patients with ischemic stroke in different periods, the correlation between the value, lesion volume of MK in acute stage and clinical scores were analyzed in patients with ischemic stroke.Results 1. In 30 patients with acute ischemic stroke, MK demonstrated inhomogeneous high signal in 19 cases, the mismatch between MK and MD were found in 25 cases. The increased amplitude of MK value and decreased of MD and ADC value within 12 hours were 65.91%±46.52%、41.49%±17.11%、36.73%±15.98%, respectively. There had significantly differences between MK and MD, ADC(Z12h MD=-4.623,P<0.01;Z12h ADC=-4.623,P<0.01). The lesion volume of MK(4.54±9.98 m L) and MD(7.36±16.82 m L) within 12 hours had significantly differences(T=-2.072,P=0.048). The lesion volume of MK within 12 hours was significantly positively correlated with infarct volume of FLAIR on 7days(r=0.946,P<0.01). The lesion value and volume of MK within 12 hours were significantly positively correlated with the NIHSS score on 7 days(r=0.571,P<0.01;r=0.678,P<0.01. 2. In 11 patients with ischemic stroke, the MK value decreased, MD and ADC value increased over time(within 12 h, 7 days, 1 month, 3 months, 6 months). There were significantly differences between ipsilateral and contralateral at different times(t12h=7.083,P<0.01;t7d=2.638,P<0.05;t3m=3.406,P<0.01;t6m=3.579,P<0.01). The MK value within 12 hours was significantly positively correlated with the NIHSS score on 7 days(r=0.739,P=0.009). The lesion volume of MK within 12 hours was significantly positively correlated with the NIHSS score on 7 days and 1 month(r7d=0.609,P=0.047;r1m=0.727,P=0.011). The lesion volume of MK within 12 hours was significantly positively correlated with the m RS score of 3 months and 6 months(r3m=0.630,P=0.038;r6m=0.612,P=0.045). The lesion mismatch between MK and MD was significantly positively correlated with the BI score of 1 month(r=0.758,P=0.007), significantly negatively correlated with the m RS score of 1 month(r=-0.746,P=0.008).Conclusions Fast DKI could demonstrate the extent of infarction and the dynamic evolution of MK, MD and ADC value in patients with acute ischemic stroke. In addition, it may be helpful for predicting of the clinical outcome of the patients.