From the Departments of Radiology (N.P.G., M.M.), Pathology (V.K.), and Nephrology (S.J.), Indraprastha Apollo Hospital, Delhi Mathura Rd, Sarita Vihar, New Delhi 110076, India.
Radiology. 2018 Jul;288(1):146-152. doi: 10.1148/radiol.2018170577. Epub 2018 Apr 10.
Purpose To evaluate whether shear-wave sonoelastography can help differentiate stable renal allograft from acute allograft dysfunction and chronic allograft dysfunction and to correlate shear-wave sonoelastography measurements with resistive index (RI), serum creatinine level, estimated glomerular filtration rate (eGFR) obtained with the Nankivell equation, and biopsy findings. Materials and Methods A prospective study of 60 patients who had undergone renal transplantation was conducted between October 2014 and March 2016. Patients were classified as having stable allograft, acute allograft dysfunction, or chronic allograft dysfunction on the basis of clinical parameters. Mean parenchymal stiffness was compared. The Banff score was used wherever applicable. Receiver operating characteristic curves were drawn to evaluate the feasibility of differentiation. Results Thirty patients had graft dysfunction (acute in 19 patients and chronic in 11). Mean parenchymal stiffness values in stable allograft, acute allograft dysfunction, and chronic allograft dysfunction were 8.51 kPa ± 2.44, 11.06 kPa ± 2.91, and 24.50 kPa ± 4.49, respectively (stable vs acute dysfunction, P = .010; stable vs chronic dysfunction, P < .001; acute sysfunction vs chronic dysfunction, P < .001). The allograft parenchymal stiffness values for patients with Banff grade I (mild interstitial fibrosis and tubular atrophy) differed significantly from those with Banff grade II (moderate interstitial fibrosis and tubular atrophy) (P = .02). Parenchymal stiffness showed a negative correlation with eGFR (r = -0.725; P < .001) and a positive correlation with RI (r = 0.562; P < .001) and serum creatinine level (r = 0.714; P < .001). The sensitivity was 73.68% and specificity was 80% in the differentiation of stable graft from acute graft dysfunction (threshold value, 10.11 kPa). Conclusion Shear-wave sonoelastographic evaluation of renal parenchymal stiffness may help differentiate stable allograft from acute and chronic allograft dysfunction. The inverse correlation of parenchymal stiffness with eGFR and positive correlation with RI and serum creatinine level show that shear-wave sonoelastography may reflect functional status of the renal allograft.
目的 评估剪切波弹性成像能否有助于鉴别稳定的移植肾与急性移植肾失功和慢性移植肾失功，并将剪切波弹性成像测量值与肾移植患者的阻力指数（RI）、血清肌酐水平、应用 Nankivell 方程估算的肾小球滤过率（eGFR）及活检结果进行相关性分析。
材料与方法 本研究为前瞻性研究，于 2014 年 10 月至 2016 年 3 月对 60 例行肾移植的患者进行研究，根据临床参数将患者分为稳定的移植肾、急性移植肾失功和慢性移植肾失功。比较各组患者的实质硬度平均值，在适用 Banff 评分标准的情况下应用该评分标准。绘制受试者工作特征曲线以评估鉴别诊断的可行性。
结果 30 例患者发生移植肾失功（19 例为急性失功，11 例为慢性失功）。稳定的移植肾、急性移植肾失功和慢性移植肾失功患者的实质硬度值分别为 8.51 kPa±2.44、11.06 kPa±2.91 和 24.50 kPa±4.49（稳定的移植肾与急性失功，P=.010；稳定的移植肾与慢性失功，P＜.001；急性失功与慢性失功，P＜.001）。Banff 分级为 I 级（轻度间质纤维化和肾小管萎缩）的患者的移植肾实质硬度值与 Banff 分级为 II 级（中度间质纤维化和肾小管萎缩）的患者的移植肾实质硬度值有显著差异（P=.02）。实质硬度与 eGFR 呈负相关（r=-0.725；P＜.001），与 RI 呈正相关（r=0.562；P＜.001），与血清肌酐水平呈正相关（r=0.714；P＜.001）。在鉴别稳定的移植肾与急性移植肾失功时，诊断阈值为 10.11 kPa，此时的灵敏度为 73.68%，特异度为 80%。
结论 对肾实质硬度进行剪切波弹性成像评估有助于鉴别稳定的移植肾与急性和慢性移植肾失功。实质硬度与 eGFR 呈负相关，与 RI 和血清肌酐水平呈正相关，表明剪切波弹性成像可能反映移植肾的功能状态。
