Preoperative assessment of split renal function in patients with renal cell carcinoma by APTw driven multiparameter MRI

Abstract Objectives To investigate the clinical value of amide proton transfer-weighted (APTw) driven multiparameter magnetic resonance imaging (MRI) in evaluating split renal function in renal cell carcinoma (RCC) patients. Methods Twenty-five healthy volunteers were recruited to evaluate the stability and reproducibility of renal APTw scanning and parameter measurements. Subsequently, 95 RCC patients were enrolled, with 187 unilateral kidneys analyzed. Based on glomerular filtration rate measured by renal dynamic scintigraphy, kidneys were categorized into normal function (n = 96), mild impairment (n = 69), and moderate-to-severe impairment (n = 22) groups. Paired-sample t-tests were performed to compare imaging parameters (APTw, apparent diffusion coefficient [ADC], and fat fraction [FF]) between the renal cortex and medulla. One-way analysis of variance was used to compare imaging parameters across different renal function status, followed by Bonferroni correction for post-hoc pairwise comparisons. Receiver-operating characteristic curves and the area under the curve were employed to assess the diagnostic performance of each parameter in differentiating renal function status. Results Renal APTw imaging demonstrated high stability and reproducibility, with quantitative measurements unaffected by renal position or gender. In healthy volunteers, the renal cortex exhibited significantly higher APTw signal than medulla (p < 0.05). As renal function impairment progressed, renal APTw signal progressively increased, and the difference in APTw between the cortex and medulla gradually diminished (p < 0.05). APTw showed high diagnostic efficacy in differentiating renal function status. Multiparametric diagnosis combining APTw, ADC, and FF further improved diagnostic performance (AUC = 0.864 for distinguishing normal from mild impairment; AUC = 0.934 for distinguishing mild from moderate-to-severe impairment). Conclusions Preliminary findings indicate that APTw driven multiparametric MRI demonstrates excellent diagnostic performance in evaluating split renal function in RCC patients, providing a potentially workflow-efficient, radiation-free and contrast-agent-free assessment method for clinical practice.