T₁ Relaxation Time for the Prediction of Renal Transplant Dysfunction

Quantitative magnetic resonance imaging (MRI) is emerging as a non-invasive tool to measure tissue scarring in renal allografts. However, whether prolonged T₁ relaxation time results in lower transplant survival rates is unknown. This retrospective cohort study analyzed the capability to predict renal allograft dysfunction based on median T₁ time. Forty-six transplant recipients with non-contrast 1.5T MRI and allograft biopsy were included. The primary endpoint was the eGFR slope over 24 months. T₁ relaxation time correlated significantly with eGFR levels at all follow-up stages. Patients with T₁ relaxation time above the median (T₁ ^high) had a consistent decline in kidney function as compared to the patient group below the median (T₁ ^low): overall eGFR slope: 11.3 vs. 1.4 mL/min/1.73 m² over 24 months, p = 0.016. Graft survival rates at 24 months were 52% in the T₁ ^high vs. 87% in the T₁ ^low group, p = 0.0015. ROC analysis discovered a positive predictive value of 52% and a negative predictive value of 91% for graft loss. T₁ mapping identified patients with a persistent decline of allograft function and an increased risk of allograft loss. MRI could significantly influence monitoring strategies in transplant surveillance, offering a safe, non-invasive alternative to traditional diagnostic methods.