超声造影定量评价脓毒症急性肾损伤肾血流灌注及其参数与炎症因子的相关性

Contrast-enhanced ultrasonography quantitative parameters for evaluation of renal perfusion in septic rats with acute renal injury and their correlation with inflammatory factors

目的:探讨超声造影定量评估脓毒症相关急性肾损伤(S-AKI)大鼠肾血流灌注及其参数对大鼠炎症反应的监测价值。方法:选取健康SD大鼠32只,平均分为模型组和对照组,模型组采用盲肠结扎穿孔术制作脓毒症大鼠,对照组仅开腹游离盲肠末端,不结扎穿孔,直接还纳关闭腹腔。于术后12 h、24 h两个时间点每组取8只大鼠行超声造影检查,并选取感兴趣区绘制时间强度曲线进行定量分析,下腔静脉取血检测血清肌酐(Scr)、尿素(Urea)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、白细胞介素10(IL-10),留取肾标本进行病理检查。采用独立样本t检验和非参数检验(Mann-Whitney U)统计不同时间点两组各指标的差异,采用Spearman相关分析超声造影定量参数[造影剂到达时间(AT)、达峰时间(TTP)、上升斜率(AS)、峰值强度(PI)、降半时间(DT/2)、下降斜率(DS)、曲线下面积(AUC)]与炎症因子的相关性。结果:(1)模型组肾功能指标Scr、Urea、炎症因子指标IL-6、TNF-α、IL-10于两个时间点均显著高于对照组,差异均具有统计学意义(P均<0.05)。(2)造影剂团注后2~4 s,肾血管快速增强,随后皮质、髓质依次显影,髓质、皮质依次消退。与对照组相比,模型组12 h肾皮质TTP增加[(10.47±1.25)s vs(8.30±1.53)s],DS、PI减小[(-0.13±0.02)dB/s vs(-0.17±0.04)dB/s;(23.90±1.36)dB vs(27.26±1.88)dB],髓质TTP、DT/2增加[(11.66±1.99)s vs(9.00±1.28)s;(62.49±4.56)s vs(52.15±7.70)s],DS减小[(-0.13±0.02)dB/s vs(-0.17±0.03)dB/s],差异均有统计学意义(t=-3.105、-3.121、4.102、-3.180、-3.268,-2.915,P=0.008、0.008、0.001、0.007、0.007、0.011),模型组24 h肾皮质AS、DS增加[(0.99±0.17)dB/s vs(0.61±0.19)dB/s;(-0.23±0.03)dB/s vs(-0.15±0.04)dB/s],DT/2、AUC减小[(42.41±3.03)s vs(61.07±6.52)s;(2477.89±113.37)dB·s vs(3024.93±253.81)dB·s],髓质AS、DS、AT增加[(1.00±0.27)dB/s vs(0.66±0.17)dB/s;(-0.23±0.06)dB/s vs(-0.15±0.04)dB/s;(4.30±0.34)s vs(3.77±0.29)s],DT/2、AUC减小[(42.73±7.02)s vs(59.64±9.23)s;(2335.75±189.77)dB·s vs(2689.72±285.45)dB·s],差异具有统计学意义(t=-4.262、5.138、7.344、5.566、-3.061、3.108、-3.349、4.124、2.921,P=0.001、<0.001、<0.001、<0.001、=0.008、=0.008、=0.005、=0.001、=0.011)。(3)肾皮质超声造影定量参数PI、AUC与血清IL-6、TNF-α、IL-10呈显著相关(r=-0.562、-0.398、-0.512;-0.540、-0.638、-0.430,P均<0.05)。(4)肾病理切片行过碘酸雪夫染色显示,模型组大鼠肾出现肾小管轮廓不清、扩张、刷状缘脱落、肾小管上皮细胞扁平化、脱落表现,24 h模型组部分肾小管管型形成;对照组大鼠病理表现正常。结论:超声造影可以实时动态观察大鼠肾血流灌注过程,定量评价血流灌注水平,初步监测机体的炎症反应状态。

Objective To explore the value of contrast-enhanced ultrasonography(CEUS)quantitative parameters in evaluating renal perfusion and monitoring inflammatory response in sepsisinduced acute renal injury(S-AKI).Methods Thirty-two healthy Sprague Dawley rats were selected and divided into either a model group or a control group.Sepsis was induced in rats by cecal ligation and puncture.For control rats,the abdominal cavity was only opened and closed,and cecal ligation and puncture were not performed.At 12 h and 24 h after modeling,eight rats from each group were taken to perform contrast-enhanced ultrasonography,and region of interest(ROI)was selected to draw time intensity curve(TIC)and perform quantitative analysis.Blood samples were taken from the inferior vena cava(IVC)to test serum creatinine(SCr),urea,interleukin(IL)-6,tumor necrosis factor-α(TNF-α),and IL-10,and the kidney was taken for pathological examination.Independent sample t test and non-parametric test(Mann-Whitney U)were used to analyze the differences between the two groups at different time points,and Spearman correlation test was used to analyze the correlation between quantitative parameters of CEUS[arrival time(AT),time to peak(TTP),ascending slope(AS),peak intensity(PI),half of descending time(DT/2),descending slope(DS),and area under curve(AUC)]and inflammatory factors.Results Renal function indexes(Scr and urea)and inflammatory factors(IL-6,TNF-α,and IL-10)in the model group were significantly higher than those of the control group at both time points(P<0.05).At 2-4 s after SonoVue bolus injection,the blood vessels of the kidney were enhanced at first,then the cortex and medulla developed successively,and the medulla and cortex disappeared in turn.Compared with the control group,in the model group at 12 h,the TTP of the renal cortex significantly increased[(10.47±1.25)s vs(8.30±1.53)s,t=-3.105,P=0.008],the DS and PI of the renal cortex significantly decreased[(-0.13±0.02)dB/s vs(-0.17±0.04)dB/s,t=-3.121,P=0.008;(23.90±1.36)dB vs(27.26±1.88)dB,t=4.102,P=0.001],TTP and DT/2 of the medulla significantly increased[(11.66±1.99)s vs(9.00±1.28)s,t=-3.180,P=0.007;(62.49±4.56)s vs(52.15±7.70)s,t=-3.268,P=0.007],and DS of the medulla significantly decreased[(-0.13±0.02)s dB/s vs(-0.17±0.03)dB/s,t=-2.915,P=0.011].Compared with the control group,in the model group at 24 h,AS and DS of the renal cortex significantly increased[(0.99±0.17)dB/s vs(0.61±0.19)dB/s,t=-4.262,P=0.001;(-0.23±0.03)dB/s vs(-0.15±0.04)dB/s,t=5.138,P<0.001],and DT/2 and AUC of the renal cortex significantly decreased[(42.41±3.03)s vs(61.07±6.52)s,t=7.344,P<0.001;(2477.89±113.37)dB•s vs(3024.93±253.81)dB•s,t=5.566,P<0.001];AS,DS,and AT of the renal medulla significantly increased[(1.00±0.27)dB/s vs(0.66±0.17)dB/s,t=-3.061,P=0.008;(-0.23±0.06)dB/s vs(-0.15±0.04)dB/s,t=3.108,P=0.008;(4.30±0.34)s vs(3.77±0.29)s,t=-3.349,P=0.005],and DT/2 and AUC of the renal medulla significantly decreased[(42.73±7.02)s vs(59.64±9.23)s,t=4.124,P=0.001;(2335.75±189.77)dB•s vs(2689.72±285.45)dB•s,t=2.921,P=0.011].The CEUS quantitative parameters PI and AUC in the renal cortex were significantly correlated with serum IL-6,TNF-α,and IL-10(r=-0.562,-0.398,-0.512,-0.540,-0.638,and-0.430,respectively,P<0.05).Renal PAS staining showed that the kidney of rats in the model group showed unclear outline of renal tubules,dilatation,shedding of brush margin,and flattening and shedding of renal tubular epithelial cells,and part of renal tubules were formed in 24 h in the model group.Conclusion CEUS can be used to dynamically assess the blood perfusion process of the rat kidney in real time,quantitative evaluate the blood perfusion level,and monitor the inflammatory reaction state of the body.