Marticorena Garcia Stephan R, Guo Jing, Dürr Michael, Denecke Timm, Hamm Bernd, Sack Ingolf, Fischer Thomas
1 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
2 Department of Nephrology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Acta Radiol. 2018 Sep;59(9):1139-1145. doi: 10.1177/0284185117748488. Epub 2017 Dec 17.
Background Monitoring of renal allograft function is essential for early identification of dysfunction and improvement of kidney transplant (KTX) outcome. Purpose To non-invasively assess renal stiffness in KTX recipients using ultrasound shear wave elastography (USE) in correlation with multifrequency magnetic resonance elastography (MRE), renal allograft function, and renal microvascular flow determined using a novel ultrasound microvascular imaging technique. Material and Methods This prospective study investigated 25 KTXs (functional KTX [FCT], n = 14; chronic KTX insufficiency [DYS], n = 11) in 20 KTX recipients (mean age = 43 ± 14 years). USE was performed using a high-frequency broadband linear transducer and compared with MRE. Shear wave velocity (SWV) was correlated with the estimated glomerular filtration rate (eGFR). Qualitative differences in renal microvascular flow were obtained using SMI. Results FCT had higher SWV than DYS in both cortex and pyramids (cortex, FCT: 3.75 ± 0.82 m/s vs. DYS: 2.79 ± 0.73 m/s, P = 0.0002; pyramid, FCT: 2.89 ± 0.46 m/s vs. DYS: 2.39 ± 0.34 m/s, P = 0.044). Cutoff values of 3.265 m/s for cortex, 2.535 m/s for pyramids, and 2.985 m/s for combined non-hilar parenchyma provided sensitivities of 72.7%, 77.8%, and 90.9% and specificities of 71.4%, 78.6%, and 85.7% for detecting renal allograft dysfunction with area under the receiver operating characteristic curve (AUC) values of 0.831, 0.841, 0.925 (95% confidence interval [CI] = 0.67-0.99, 0.66-1.02, 0.83-1.03). USE correlated positively with eGFR ( r = 0.741, P = 0.0004) and with MRE-derived SWV ( r = 0.562, P = 0.004). Renal microvascular flow was decreased in DYS. Conclusion USE is sensitive to renal allograft dysfunction, which is characterized by reduced SWV and renal perfusion. USE has higher image resolution than MRE, while MRE has slightly better diagnostic accuracy.
背景 监测肾移植功能对于早期识别功能障碍和改善肾移植（KTX）结局至关重要。目的 使用超声剪切波弹性成像（USE）与多频磁共振弹性成像（MRE）、肾移植功能以及使用新型超声微血管成像技术测定的肾微血管血流相关，以无创评估KTX受者的肾硬度。材料与方法 这项前瞻性研究调查了20名KTX受者（平均年龄=43±14岁）的25例肾移植（功能正常的肾移植[FCT]，n = 14；慢性肾移植功能不全[DYS]，n = 11）。使用高频宽带线性换能器进行USE，并与MRE进行比较。剪切波速度（SWV）与估计肾小球滤过率（eGFR）相关。使用SMI获得肾微血管血流的定性差异。结果 FCT在皮质和锥体中的SWV均高于DYS（皮质，FCT：3.75±0.82 m/s vs. DYS：2.79±0.73 m/s，P = 0.0002；锥体，FCT：2.89±0.46 m/s vs. DYS：2.39±0.34 m/s，P = 0.044）。皮质的截断值为3.265 m/s，锥体为2.535 m/s，非肾门实质联合为2.985 m/s，检测肾移植功能障碍的敏感性分别为72.7%、77.8%和90.9%，特异性分别为71.4%、78.6%和85.7%，受试者操作特征曲线（AUC）下面积值分别为0.831、0.841、0.925（95%置信区间[CI]=0.67 - 0.99、0.66 - 1.02、0.83 - 1.03）。USE与eGFR呈正相关（r = 0.741，P = 0.0004），与MRE衍生的SWV呈正相关（r = 0.562，P = 0.004）。DYS中肾微血管血流减少。结论 USE对肾移植功能障碍敏感，其特征为SWV降低和肾灌注减少。USE的图像分辨率高于MRE，而MRE的诊断准确性略好。
