DWI中基于单指数与IVIM双指数模型早期预测淋巴瘤疗效效能比较

摘要

Objective To compare the prediction efficacy for chemotherapy response of lymphoma between monoexponen-tial and biexponential model based on intravoxel incoherent motion (IVIM) in multiple b value DWI.Methods Totally 22 patients of lymphoma confirmed by pathology who received chemotherapy underwent regular MRI and multiple b value DWI before and after 2 cycles of chemotherapy.The true diffusion coneffcient (D),pseudo diffusion coneffcient (D*) and perfusion fraction (f) were obtained according to the biexponential model,and the apparent diffusion coefficient (ADC) was obtained according to the monoexponential model.The chemotherapy response of lymphoma were classified into complete response (CR),partial response (PR),stable disease (SD) and progressive disease (PD) according to response evaluation criteria in solid tumors after 2 cycles of chemotherapy.Pretherapeutic D,f,D* and ADC value among different response groups were compared.The prediction efficacy of D and ADC value for chemotherapy response were assessed.Results There were 49 lymphoma nodes in CR group,17 lymphoma nodes in PR group and 8 lymphoma nodes in SD group.Pretherapeutic D and ADC value in SD group were lower than those in CR and PR group (all P＜0.05),which had no differences between CR and PR group (both P＞0.05).There were no difference of f and D* value among CR,PR,and SD group (all P＞0.05).Taken 0.48× 10-3 mm2/s and 0.49× 10-3 mm2/s as cut-off value of pretherapeutic D and ADC value for predicting good chemotherapy response (CR and PR),the sensitivity,specificity and area under the curve was 100％,75.76％,0.890 and 100％,84.85％,0.893,respectively,with no statistical difference of prediction efficacy between D and ADC (Z=0.086,P=0.931).Conclusion D value obtained from biexponential model based on IVIM and ADC value obtained from monoexponential model can both early predict the chemotherapy response of lymphoma,with similar prediction efficacy.%目的 比较多b值DWI中单指数模型和基于体素内不相干运动(IVIM)的双指数模型早期预测淋巴瘤疗效的价值.方法 纳入接受化疗、经病理确诊的淋巴瘤患者22例.患者于治疗前、2个周期化疗后分别进行常规MRI和多b值DWI,根据IVIM双指数模型获得真性扩散系数(D值)、假性扩散系数(D*值)和灌注分数(f值),根据单指数模型获得ADC值.2个周期化疗后根据实体瘤疗效评价标准评估疗效,分为完全缓解(CR)、部分缓解(PR)、稳定(SD)和进展(PD),比较不同疗效组治疗前D、f、D*、ADC值差异,评价D值和ADC值预测疗效效能.结果 CR组49个淋巴结、PR组17个淋巴结、SD组8个淋巴结.CR组和PR组治疗前D值和ADC值差异均无统计学意义(P均＞0.05),SD组治疗前D值和ADC值均低于CR组和PR组(P均＜0.05),CR组、PR组和SD组f值和D*值差异均无统计学意义(P均＞0.05).分别以0.48×10-3mm2/s和0.49×10-3mm2/s为治疗前D值和ADC值预测较好疗效(CR和PR)阈值,敏感度、特异度和曲线下面积分别为100％、75.76％、0.890和100％、84.85％、0.893,二者预测化疗疗效差异无统计学意义(Z=0.086,P=0.931).结论 基于IVIM的双指数模型所获得D值和单指数模型所获得ADC值早期预测淋巴瘤疗效效能均较好,无明显差异.