CAJ | 학술논문

目的探讨扩散峰度成像（ DKI）相关参数在脑梗死不同时期的变化。方法对114例脑梗死患者行常规DWI及DKI扫描，根据患者出现临床症状至MR检查的时间分为5组，分别为超急性期（发病6 h以内）8例、急性期（＞6～24 h）14例、亚急性早期（＞24 h～7 d）60例、亚急性晚期（＞7～14 d）20例、慢性期（＞14 d～2个月）12例。经后处理分别得到ADC及DKI相关参量图。分析比较各扩散参量在脑梗死不同时期的变化趋势，并计算不同参量在梗死区域的改变程度。采用配对样本t检验对各期脑梗死区域各参量平均值与对侧正常镜像区域进行比较，梗死区域各参量与检查时间的相关性采用Pearson相关性分析。结果除慢性期外，脑梗死区域在平均扩散峰度（ MK）、轴向峰度（K∥）、径向峰度（K⊥）图上呈不均匀高信号，平均扩散系数（MD）、轴向扩散张量（D∥）、垂直扩散张量（ D⊥）图呈均匀低信号。 MK值在超急性期、急性期、亚急性早期及亚急性晚期脑梗死区（分别为1.331±0.357、1.578±0.453、1.519±0.455、1.403±0.275）较对侧正常镜像区域（ MK值分别为0.850±0.236、0.827±0.194、0.865±0.144、0.939±0.212）升高，差异有统计学意义（ t值分别为5.242、6.907、12.416、5.629，P值均＜0.01）。 MK、K∥、K⊥值在急性期、亚急性早期升高到最高峰，其升高幅度远较MD、D∥、D⊥减低的幅度大，随后逐渐减低，并有趋于正常化趋势。 MK、MD、ADC值与脑梗死发病时间呈正相关（r值分别为0.354、0.747、0.723，P值均＜0.05）。结论 DKI可提供较常规DWI更多的扩散信息，更能反映组织微观结构的改变。
목적탐토확산봉도성상（ DKI）상관삼수재뇌경사불동시기적변화。방법대114례뇌경사환자행상규DWI급DKI소묘，근거환자출현림상증상지MR검사적시간분위5조，분별위초급성기（발병6 h이내）8례、급성기（＞6～24 h）14례、아급성조기（＞24 h～7 d）60례、아급성만기（＞7～14 d）20례、만성기（＞14 d～2개월）12례。경후처리분별득도ADC급DKI상관삼량도。분석비교각확산삼량재뇌경사불동시기적변화추세，병계산불동삼량재경사구역적개변정도。채용배대양본t검험대각기뇌경사구역각삼량평균치여대측정상경상구역진행비교，경사구역각삼량여검사시간적상관성채용Pearson상관성분석。결과제만성기외，뇌경사구역재평균확산봉도（ MK）、축향봉도（K∥）、경향봉도（K⊥）도상정불균균고신호，평균확산계수（MD）、축향확산장량（D∥）、수직확산장량（ D⊥）도정균균저신호。 MK치재초급성기、급성기、아급성조기급아급성만기뇌경사구（분별위1.331±0.357、1.578±0.453、1.519±0.455、1.403±0.275）교대측정상경상구역（ MK치분별위0.850±0.236、0.827±0.194、0.865±0.144、0.939±0.212）승고，차이유통계학의의（ t치분별위5.242、6.907、12.416、5.629，P치균＜0.01）。 MK、K∥、K⊥치재급성기、아급성조기승고도최고봉，기승고폭도원교MD、D∥、D⊥감저적폭도대，수후축점감저，병유추우정상화추세。 MK、MD、ADC치여뇌경사발병시간정정상관（r치분별위0.354、0.747、0.723，P치균＜0.05）。결론 DKI가제공교상규DWI경다적확산신식，경능반영조직미관결구적개변。
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 groups:8 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.