DWI、IVIM及DCE-MRI参数与软组织肿瘤Ki-67表达相关性的研究

Study on the correlation between DWI,IVIM,and DCE-MRI parameters and Ki-67 expression in soft tissue tumors

目的探究扩散加权成像(diffusion weighted imaging,DWI)、体素内不相干运动(intravoxel incoherent motion,IVIM)和动态对比增强磁共振成像(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)参数与软组织肿瘤Ki-67表达的相关性。材料与方法回顾性纳入56例经病理证实的软组织肿瘤患者,将Ki-67指数>20%的病例纳入高表达组(n=22)、≤20%的病例纳入低表达组(n=34)。比较组间DWI、IVIM和DCE-MRI参数,包括表观扩散系数(apparent diffusion coefficient,ADC)、真扩散系数(pure diffusion coefficient,D)、假扩散系数(pseudo-diffusion coefficient,D^(*))、灌注分数(perfusion fraction,f)、速率常数(rate constant,K_(ep))、容积转运常数(volume transfer constant,K^(trans))、血管外细胞外间隙容积分数(extravascular extracellular volume fraction,V_(e)),并应用Pearson相关系数分析差异具有统计学意义的参数与Ki-67指数相关性。结果Ki-67低表达组ADC和D值显著高于高表达组,K^(trans)和K_(ep)值显著低于高表达组(P均<0.05);其中,ADC和D值与Ki-67指数呈负相关(r=-0.637、-0.625,P均<0.001);K^(trans)呈正相关(r=0.263,P=0.050)。ADC值在区分软组织肿瘤中Ki-67表达状态的曲线下面积(area under the curve,AUC)最高,为0.920(0.845~0.994)。结论ADC、D、K^(trans)和K_(ep)参数可有效预测软组织肿瘤Ki-67表达,其中ADC和D是预测Ki-67表达状态的最佳参数,可以为临床诊断、治疗及预后判断提供帮助。

Objective:To investigate the correlation between diffusion weighted imaging(DWI),intravoxel incoherent motion(IVIM),and dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters and the expression of Ki-67 in soft tissue tumors.Materials and Methods:A retrospective study included 56 patients with pathologically confirmed soft tissue tumors,divided into a high expression group(n=22)with a Ki-67 index of>20%and a low expression group(n=34)with a Ki-67 index of≤20%according to the Ki-67 index.The study compared DWI,IVIM,and DCE-MRI parameters between the groups,including apparent diffusion coefficient(ADC),pure diffusion coefficient(D),pseudo-diffusion coefficient(D^(*)),perfusion fraction(f),rate constant(K_(ep)),volume transfer constant(K^(trans)),and extracellular extravascular space volume fraction(V_(e)),and analyzed their correlation with Ki-67 index.It also applied the Pearson correlation coefficient to analyze the significant correlation of parameters with the Ki-67 index that showed significant differences between the groups.Results:The ADC and D values were significantly higher in the low Ki-67 expression group than in the high expression group,while K^(trans)and K_(ep)values were significantly lower(P<0.05 for all).ADC and D values showed a negative correlation with Ki-67 index(r=−0.637,−0.625,P<0.001),whereas K^(trans)showed a positive correlation(r=0.263,P=0.050).ADC had the highest area under the curve(AUC)in distinguishing Ki-67 expression status in soft tissue tumors,at 0.920(0.845-0.994).Conclusions:ADC,D,K^(trans),and K_(ep)can effectively predict Ki-67 expression in soft tissue tumors,with ADC and D being the best parameters for predicting the Ki-67 expression status,providing assistance in clinical diagnosis,treatment,and prognosis assessment.