One-stop early noninvasive evaluation of renal allograft rejection and fibrosis: microstructural mapping via time-dependent diffusion MRI

作者：Zhouyan Liao, Gen Chen, Kuiyuan Liu, Siyuan Ma, Hao Tang, Haotian Li, Ting Yin, Ihab R. Kamel, Jeong Min Lee, Dan Wu, Zhen Li · 发表于：EBioMedicine · 年份：2025 · DOI：10.1016/j.ebiom.2025.106034 · 被引用次数：4 · 研究领域：MRI in cancer diagnosis、Renal and Vascular Pathologies、Renal Transplantation Outcomes and Treatments

Background Functional MRI offers promise for noninvasive detection of renal allograft injury, but conventional models lack biological specificity. This study aimed to evaluate the clinical utility of time-dependent diffusion MRI (td-dMRI) for detecting rejection and fibrosis in renal allografts. Methods In this prospective observational study at a tertiary center in China, adult patients with renal allograft undergoing indication biopsies between April 2024 and June 2025 were enrolled. Microstructural maps were derived from td-dMRI, intravoxel incoherent motion, diffusion kurtosis imaging, stretched exponential model, fractional order calculus, and continuous-time random-walk model. To address overfitting risk from limited samples, final multivariate models were constructed using Firth-penalised multinomial logistic regression. Model performance was evaluated via confusion matrices, sensitivity, specificity, and overall accuracy. The incremental diagnostic value of MRI parameters was quantified by comparing the area under the curve of baseline clinical and final multivariable models. Findings A total of 100 patients (67 males, 33 females) were analysed. Among them, 41 patients had acute rejection and 13 had chronic rejection; 67 had mild fibrosis, 19 moderate, and 14 severe fibrosis. Td-dMRI-derived cortical cell diameter (diameter cortex ) significantly distinguished fibrosis grades, while cellularity medulla identified early fibrotic changes. For rejection, diameter cortex ...