缺血性脑卒中早期DKI、DWI预测病灶最终转变的对比研究

目的探究扩散峰度成像(diffusion kurtosis imaging,DKI)与扩散加权成像(diffusion weighted imaging,DWI)预测急性脑梗死病灶最终转变的能力,以便为脑梗死核心区的准确判断提供补充。材料与方法选取急性脑梗死病例18例,分别于发病48 h内、30天后进行2次MRI扫描,绘制急性期DWI图、DKI的平均扩散峰度(mean kurtosis,MK)参数图与随访T2WI图显示的病灶范围,测量并计算3组图像中的病灶体积。不同参数图像中各体积值之间的差异采用Kruskal-Wallis H检验评估;并采用Spearman秩相关分析研究基线DWI、MK图体积与复查T2WI软化灶体积之间的相关性。结果急性期DWI、MK图与复查T2WI异常区域的体积,经Krustal-Wallis H检验,差异无统计学意义(H=5.819,P0.05)。随访T2WI的病灶体积(766.3±1406.4)mm~3与急性期MK图的病灶体积(905.8±1605.4)mm~3呈高度相关(r=0.977,P0.01),与急性期DWI的病灶体积(1642.5±3296.9)mm~3呈中度相关(r=0.548,P0.05)。结论急性期DKI较DWI与病灶的最终坏死灶范围具有更好的相关性,DKI更能准确地预测病灶的最终转变。

The comparative study of ischemic stroke early DKI,DWI lesions predicted the ifnal transition

AbstractObjective:Diffusion kurtosis imaging (DKI) has lately been postulated as a complementary MRI method to stratify the heterogeneous damaged DWI lesion. Compare the ability of DWI and DKI predicting lesion transformation, to supplement the precise deifnition of infarct core area.Materials and Methods:Eighteen cases of ischemic stroke were recruited for our study, who had infarct on DWI at baseline, and had follow-up MR scans. Pre-deifned target imaging time points, obtained on a 3.0 T MR scanner, were<48 h and≥30 d post-stroke. Drawing the range of lesion from acute DKI (MK mapping), DWI and ifnal T2WI, and calculate the lesion volume. Relationship between baseline DWI, MK map and follow-up T2WI was analyzed usingSpearman rank-order correlation test, andKruskal-WallisH test was used to compare the volumes among three groups.Results:There was no difference among the volume of DWI, MK map and follow-up T2WI (H=5.819,P>0.05). Follow-up T2WI infarct volume (766.3±1406.4) mm3 was correlated with both volume predicted with the MK map (905.8±1605.4) mm3 and baseline DWI volume (1642.5±3296.9) mm3, which showed baseline DKI (MK mapping) infarct volume had stronger correlation with ifnal T2 infarct volume than DWI (r=0.977,P<0.001;r=0.548,P<0.05, respectively).Conclusion:Final infarct volume was closer to the lesion shown on DKI than on DWI, DKI can predict the ifnal transition more accuratly.