A study for the time course of cerebral infarction with diffusion kurtosis imaging / 中华放射学杂志

ABSTRACT

Objective To investigate the time course of cerebral infarction with diffusion kurtosis imaging-related parameters.Methods According to the time interval from symptom onset to MRI examination, 114 cases of cerebral infarction were divided into five groups8 cases of hyperacute phase(less than 6 hours), 14 cases of acute(>6-24 h), 60 cases of early subacute(>24 h-7 d), 20 cases of late subacute(>7-14 d), and 12 cases of chronic phase ( >14 d-2 months).They underwent routine diffusion weighted imaging (DWI) and diffusion kurtosis imaging (DKI) scanning, and apparent diffusion coefficient ( ADC) and DKI-derived parameters were obtained from them.The derived diffusion parameters were compared among different phases in the patients , and the percent of changes in the infarcted regions were calculated.Paired t-test was used to compare the difference of each parameter between the infarcted region and contralateral normal region , and their correlation with time interval was tested using Pearson correlation analysis.Results Except for chronic phase , mean kurtosis ( MK) , axial kurtosis ( K∥) , radial kurtosis (K⊥)map showed uneven high signal in the infarcted regions , while mean diffusion(MD), axial diffusion(D∥), radial diffusion(D⊥) showed uniform low signal.MK values in the infarcted regions of hyperacute, acute, early subacute and late subacute phase (1.331 ±0.357,1.578 ±0.453,1.519 ±0.455, 1.403 ±0.275 ) increased significantly , compared with the contralateral normal mirror regions ( 0.850 ± 0.236,0.827 ±0.194,0.865 ±0.144,0.939 ±0.212) (t values were 5.242,6.907,12.416,5.629, respectively.P values were all less than 0.01 ).MK, K∥, K⊥ achieved a peak in the acute and early subacute phase , and showed more amplitude than the decrease of MD , D∥, D⊥.Then they gradually reduced, and tended to normalize.MK, MD, ADC had a significant correlation with the time onset of cerebral infarction ( r was 0.354, 0.747, 0.723, respectively, P values were all less than 0.05 ).Conclusion Diffusion kurtosis imaging can provide more diffusion information than conventional DWI , which can better reflect the microstructure changes in tissue.