Pathology and Imaging in Kidney Allografts

Background: Renal transplantation is the optimal treatment for patients with renal failure. However, transplant life-span is finite and commonly limited due to the development of chronic rejection and other causes of irreversible fibrosis. At present, renal transplant biopsy is required to diagnose the cause of transplant dysfunction. Renal biopsies are invasive procedures that carry risks of bleeding, damage to the transplant and discomfort to patients. Functional magnetic resonance imaging (MRI) of the kidneys is an emerging field of research that has potential to non-invasively define and quantify parenchymal renal disease including fibrosis and inflammation. There is a paucity of data correlating multi-parametric renal MRI sequences with histological findings on biopsy, especially in patients with renal transplants. Study participants: 70 adult renal transplant recipients who have been referred for a clinically indicated biopsy of their transplant kidney. Study design: Participants will undergo multi-parametric renal MRI at time of biopsy. In patients who receive treatment for acute rejection, a second renal MRI will be undertaken at completion of treatment. Blood tests for fibrosis biomarkers and routine clinical measures of transplant function will be obtained at time of MRI scanning. Objectives: 1. Assess the correlation between functional renal MRI sequences and histological markers of fibrosis and inflammation. 2. Assess the change in functional MRI sequences in response to treatment for acute rejection in renal transplant recipients.