Diagnostic and prognostic potential of multiparametric renal MRI in Kidney transplant patients

Background: Multiparametric MRI provides assessment of functional and structural parameters in kidney allografts. Itoffers a non-invasive alternative to the current reference standard of kidney biopsy. Purpose: To evaluate the diagnostic and prognostic utility of MRI parameters in the assessment of allograft function in thefirst 3-months post-transplantation. Study Type: Prospective. Subjects: 32 transplant recipients (54 17 years, 20 females), divided into two groups according to estimated glomerularfiltration rate (eGFR) at 3-months post-transplantation: inferior graft function (IGF; eGFR<45 mL/min/1.73 m2,n=10) andsuperior graft function (SGF; eGFR≥45 mL/min/1.73 m2,n=22). Further categorization was based on the need for hemo-dialysis (C1) and decrease in s-creatinine (C2) at 1-week post-transplantation: delayed-graft-function (DGF:n=4 C1,n=10 C2) and early graft-function (EGF:n=28 C1,n=22 C2). Field Strength/Sequence: 3-T, pseudo-continuous arterial spin labeling, T1-mapping, and diffusion-weighted imaging. Assessment: Multiparametric MRI was evaluated at 1-week in all patients and 3-months after transplantation in 28 patients. Renalbloodflow (RBF), diffusion coefficients (ADC,ΔADC,D,ΔD,D*,flowing fractionf),T1andΔT1were calculated in cortex andmedulla. The diagnostic and prognostic value of these parameters, obtained at 3-months and 1-week post-transplantation,respectively, was evaluated in the cortex to discriminate between DGF and EGF, and between SGF and IGF. Statistical Tests: Logistic regression, receiver-operating-characteristics, area-under-the-curve (AUC), confidence intervals(CIs), analysis-of-variance,t-test, Wilcoxon-Mann–Whitney test, Fisher’s exact test, Pearson’s correlation.P-value<0.05 wasconsidered significant. Results: DGF patients exhibited significantly lower cortical RBF and f and higherD*. The diagnostic value of MRI fordetecting DGF was excellent (AUC=100%). Significant differences between patients with IGF and SGF were found inRBF,ΔT1, andΔD. Multiparametric MRI showed higher diagnostic (AUC=95.32%; CI: 88%–100%) and prognostic(AUC=97.47%, CI: 92%–100%) values for detecting IGF than eGFR (AUC=89.50%, CI: 79%–100%). Data Conclusion: Multiparametric MRI may show high diagnostic and prognostic value in transplanted patients, yieldingbetter results compared to eGFR measurements. Level of Evidence: 2. Technical Efficacy: Stage 1.