Evaluating the added value of multiparametric functional MRI in predicting renal function response to renal artery stenting in severe atherosclerotic renal artery stenosis.

OBJECTIVE

To explore the potential of Intravoxel Incoherent Motion Diffusion (IVIM) and Arterial Spin Labeling (ASL) in predicting the short-term effectiveness of post-revascularization for severe atherosclerotic renal artery stenosis.

MATERIAL AND METHODS

A retrospective analysis of 88 cases from October 2018 to February 2023 was conducted. Patients were divided into Responder and Non-Responder groups based on renal function outcomes at their last follow-up. Clinical data were compared between the groups, and preoperative functional MRI images were analyzed. ROIs were outlined for the affected and both kidneys. Measurements included ASL-derived renal blood flow (RBF), IVIM's pseudo-diffusion coefficient (D*), perfusion fraction (f), true diffusion coefficient (D), and the conventional apparent diffusion coefficient (ADC).Multivariate logistic regression identified independent clinical predictors of benefit, and a clinical prediction model was developed. Model performance was assessed using Receiver Operating Characteristic (ROC) curves and Decision Curve Analysis(DCA) curves.

RESULTS

In the training cohort of 54 non-responders and 34 responders, no quantitative parameters of bilateral kidneys showed statistical significance in predicting Responders (all p > 0.05). Pre-treatment eGFR, presence of diabetes, and the D value of the affected kidney were identified as independent factors for predicting short-term treatment effectiveness. The combined clinical-functional imaging model yielded a higher AUC at 0.796 (95 % CI: 0.690-0.897). Decision curve analysis further confirmed the better net benefit of combined model.

CONCLUSION

Beyond clinical characteristics, functional MRI had the potential to predict response of stenting for severe atherosclerotic renal artery stenosis.