Garcia Stephan Rodrigo Marticorena, Oppenheimer Jonas, Meyer Tom, Friedersdorff Frank, Sack Ingolf
Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Clinic of Urology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
J Magn Reson Imaging. 2025 Sep;62(3):792-799. doi: 10.1002/jmri.29799. Epub 2025 Apr 17.
Kidney transplant (KTx) function assessment is important in treatment planning, while conventional MRI markers lack sensitivity for KTx function. Mechanical kidney properties may serve as MRI markers for renal allograft function.
To determine if multifrequency MR elastography (MRE) is associated with KTx function.
Prospective, longitudinal.
Twelve kidney donors (51 ± 9 years, 8 females) and 12 allograft recipients (48 ± 17 years, 2 females).
FIELDSTRENGTH/SEQUENCE: 1.5 T, MRE, and diffusion-weighted MRI based on spin-echo echo-planar imaging and T2-weighted MRI volumetry.
Kidney donors were imaged pre- and post-KTx, while allograft recipients were imaged post-KTx. Renal function was assessed using creatinine levels (at 1 week, 1 month, and 3 years post-KTx in recipients) and glomerular filtration rate (GFR; donors pre-KTx) based on Tc-99m-MAG3 scintigraphy. Kidney volumes were measured by MRI segmentations, and ADC, shear-wave speed (SWS), and loss-angle maps were reconstructed. The correlations between MR parameters, GFR, and creatinine level (minimum value over study period) were investigated.
Wilcoxon tests and Pearson correlation coefficients (R). A p < 0.05 was considered statistically significant.
No significant lateral differences in renal volume (153 ± 34 cm, p = 0.34) or SWS (2.5 ± 0.4 m/s, p = 0.20) were found pre-KTx. Volume and SWS increased significantly post-KTx in reference kidneys (volume: +13%, SWS: +11%) and in transplants in recipients (volume: +20%, SWS: +32%). SWS, but not volume (p = 0.75), correlated positively with GFR in donors pre-KTx (R = 0.67) while both SWS (R = ‑0.62) and volume (R = -0.77) negatively correlated with creatinine levels post-KTx. ADC was sensitive to KTx-associated changes in renal function in donors (3% ± 5%) but not recipients (p = 0.88).
MRE provides valuable information on renal function and could serve as a baseline for longitudinal monitoring of kidney transplants. Parenchymal stiffening post-KTx had significantly larger effect sizes in denervated allografts than in reference donor kidneys with intact autoregulation of renal blood flow.
Stage 2.
肾移植（KTx）功能评估对治疗方案的制定很重要，而传统MRI标志物对KTx功能缺乏敏感性。肾脏的力学特性可能作为同种异体肾移植功能的MRI标志物。
确定多频磁共振弹性成像（MRE）是否与KTx功能相关。
前瞻性纵向研究。
12名肾脏供体（51±9岁，8名女性）和12名同种异体肾移植受者（48±17岁，2名女性）。
场强/序列：1.5T，基于自旋回波平面成像的MRE、扩散加权MRI以及T2加权MRI容积测量。
对肾脏供体在KTx前后进行成像，对同种异体肾移植受者在KTx后进行成像。根据肌酐水平（受者在KTx后1周、1个月和3年时）以及基于Tc-99m-MAG3闪烁扫描法测定的肾小球滤过率（GFR；供体在KTx前）评估肾功能。通过MRI分割测量肾脏体积，并重建表观扩散系数（ADC）、剪切波速度（SWS）和损耗角图。研究MR参数、GFR和肌酐水平（研究期间的最小值）之间的相关性。
Wilcoxon检验和Pearson相关系数（R）。p<0.05被认为具有统计学意义。
在KTx前，未发现肾脏体积（153±34cm，p=0.34）或SWS（2.5±0.4m/s，p=0.20）存在显著的左右差异。在KTx后，供体肾脏（体积：增加13%，SWS：增加11%）和受者移植肾（体积：增加20%，SWS：增加32%）的体积和SWS均显著增加。在供体KTx前，SWS与GFR呈正相关（R=0.67），而体积与GFR无相关性（p=0.75）；在KTx后，SWS（R=-0.62）和体积（R=-0.77）均与肌酐水平呈负相关。ADC对供体KTx相关的肾功能变化敏感（3%±5%），但对受者不敏感（p=0.88）。
MRE提供了有关肾功能的有价值信息，可作为肾移植纵向监测的基线。与具有完整肾血流自动调节功能的供体参考肾脏相比，KTx后实质硬化在去神经支配的同种异体肾移植中的效应大小显著更大。
2级。
2级。
