肾脏不同区域体素内不相干运动扩散加权成像定量参数诊断IgA肾病的价值

Value of intravoxel incoherent motion diffusion-weighted imaging quantitative parameters in different regions of kidney in the diagnosis of IgA nephropathy

目的探讨肾脏不同区域体素内不相干运动扩散加权成像(IVIM-DWI)参数在区别IgA肾病患者与健康志愿者中的价值。方法本研究为横断面研究,前瞻性收集2022年2月至2023年9月在解放军总医院第一医学中心接受肾脏穿刺活检术(左肾下极)并经病理证实的84例IgA肾病患者(IgA肾病组)及34例健康志愿者(对照组)的肾脏IVIM-DWI图像资料,分别在右肾皮质、髓质和实质勾画感兴趣区,测量相应区域的表观扩散系数(ADC)、真扩散系数(D)、假性扩散系数(D^(*))和灌注分数(f)。采用独立样本t检验或Mann-Whitney U检验比较IgA肾病组与对照组间各区域IVIM-DWI参数的差异,对差异有统计学意义的参数进行受试者操作特征曲线分析,计算曲线下面积(AUC)。结果IgA肾病组与对照组间肾皮质ADC、肾实质ADC、肾皮质D、肾实质D和肾髓质f差异有统计学意义(Z=-3.03、-2.21、-2.62、-2.03、-2.03,P=0.002、0.027、0.009、0.043、0.042),其诊断IgA肾病的AUC(95%CI)分别为0.679(0.586~0.762)、0.630(0.537~0.717)、0.654(0.535~0.774)、0.619(0.497~0.742)和0.620(0.495~0.745)。2组间肾髓质ADC、D,肾皮质、髓质和实质D*,肾皮质和肾实质f差异无统计学意义(P>0.05)。结论肾脏IVIM-DWI定量参数受不同测量区域影响,其中肾皮质和肾实质ADC、D和肾髓质f可用于初步诊断IgA肾病。

Objective To explore the value of intravoxel incoherent motion diffusion-weighted imaging(IVIM-DWI)parameters in different regions of the kidney in distinguishing IgA nephropathy(IgAN)patients from healthy volunteers.Methods This study was a cross-sectional study.Eighty-four patients diagnosed with IgAN(IgAN group)who underwent renal biopsy(lower pole of the left kidney)and were pathologically confirmed at the First Medical Center of PLA General Hospital from February 2022 to September 2023 and thirty-four healthy volunteers(control group)were included prospectively.The regions of interest were outlined in the right renal cortex,medulla,and parenchyma for all subjects,and the apparent diffusion coefficient(ADC),true diffusion coefficient(D),pseudo-diffusion coefficient(D^(*)),and perfusion fraction(f)were measured in the corresponding regions.The differences in IVIM-DWI parameters between the IgAN group and the control group were compared using the student′s t-test or the Mann-Whitney U test.Receiver operating characteristic curve analysis was performed on the parameters with statistically significant differences,and the area under the curve(AUC)was calculated.Results There were statistically significant differences in renal cortical ADC,renal parenchymal ADC,renal cortical D,renal parenchymal D,and renal medullary f values between the IgAN group and the control group(Z=-3.03,-2.21,-2.62,-2.03,-2.03;P=0.002,0.027,0.009,0.043,0.042).The AUCs(95%CI)for diagnosing IgAN using renal cortical ADC,renal parenchymal ADC,renal cortical D,renal parenchymal D,and renal medullary f values were 0.679(0.586-0.762),0.630(0.537-0.717),0.654(0.535-0.774),0.619(0.497-0.742),and 0.620(0.495-0.745),respectively.There were no statistically significant differences in renal medullary ADC,D,renal cortex,medulla and parenchyma D*,renal cortical and renal parenchymal f values between the two groups(P>0.05).Conclusion The quantitative parameters of renal IVIM-DWI are influenced by different measurement regions,among which the ADC,D of renal cortex and parenchyma,and f of renal medulla can be used for the initial diagnosis of IgAN.