Department of Internal Medicine IV-Nephrology and Hypertension, Saarland University Hospital, Kirrberger Strasse, 66421 Homburg/Saar, Germany.
Radiology. 2012 Sep;264(3):894-902. doi: 10.1148/radiol.12111533. Epub 2012 Jul 6.
To determine whether the difference of resistive indexes (RIs) in spleen and kidney (DI-RISK) is a more specific ultrasonographic (US) marker of intrarenal parenchymal damage than intrarenal RI alone.
The study was approved by the local ethics committee. All study participants provided informed consent. The authors defined standard values for renal RI, splenic RI, and DI-RISK in 152 healthy subjects; carotid intima media thickness (IMT) was assessed as a marker of systemic vascular disease. Next, the authors measured these US parameters and collected echocardiographic data in 290 patients with chronic kidney disease (stage 2-4) recruited between September 2008 and February 2011 to evaluate the DI-RISK across the spectrum of stages of kidney function. Correlation coefficients were calculated with the Spearman test, and multivariate linear regression was used to analyze independent predictors of renal RI, splenic RI, and DI-RISK.
Healthy subjects had a mean age of 34.3 years ± 8.7, and patients with chronic kidney disease had a mean age of 65.0 years ± 12.3 (P < .001). In healthy subjects, both renal and splenic RIs were associated with IMT (renal RI: r = 0.19, P = .022; splenic RI: r = 0.23, P = .005); there was no correlation between DI-RISK and IMT (r = -0.10, P = .215). Similarly, in patients with chronic kidney disease, renal and splenic RIs correlated with IMT (renal RI: r = 0.33, P < .001; splenic RI: r = 0.30, P = .001). DI-RISK was associated with the estimated glomerular filtration rate (eGFR; r = -0.19, P = .001) but not with IMT (r = 0.08, P = .174). At multivariate regression analysis, DI-RISK was independently associated with eGFR but not with extrarenal factors.
In patients with chronic kidney disease, renal RIs do not selectively indicate organ damage, but also mirror systemic vascular disease. The authors introduced DI-RISK as a potential US marker that may more specifically reflect kidney damage.
确定脾肾阻力指数差（DI-RISK）是否比单纯肾内 RI 更能作为肾脏实质损伤的特异性超声（US）标志物。
本研究经当地伦理委员会批准，所有研究对象均签署知情同意书。作者在 152 名健康受试者中定义了肾 RI、脾 RI 和 DI-RISK 的标准值；颈动脉内膜中层厚度（IMT）被评估为系统性血管疾病的标志物。随后，作者在 2008 年 9 月至 2011 年 2 月期间招募的 290 名慢性肾脏病（2-4 期）患者中测量了这些 US 参数并收集了超声心动图数据，以评估 DI-RISK 在肾功能各阶段的变化。采用 Spearman 检验计算相关系数，采用多元线性回归分析肾 RI、脾 RI 和 DI-RISK 的独立预测因子。
健康受试者的平均年龄为 34.3 岁±8.7 岁，慢性肾脏病患者的平均年龄为 65.0 岁±12.3 岁（P<0.001）。在健康受试者中，肾内和脾内 RI 均与 IMT 相关（肾 RI：r=0.19，P=0.022；脾 RI：r=0.23，P=0.005）；而 DI-RISK 与 IMT 无相关性（r=-0.10，P=0.215）。同样，在慢性肾脏病患者中，肾内和脾内 RI 与 IMT 相关（肾 RI：r=0.33，P<0.001；脾 RI：r=0.30，P=0.001）。DI-RISK 与估计肾小球滤过率（eGFR；r=-0.19，P=0.001）相关，但与 IMT 无关（r=0.08，P=0.174）。多元回归分析显示，DI-RISK 与 eGFR 独立相关，而与肾外因素无关。
在慢性肾脏病患者中，肾内 RI 并不能选择性地提示器官损伤，也反映了系统性血管疾病。作者提出 DI-RISK 作为一种潜在的 US 标志物，可能更能特异性地反映肾脏损伤。
