Quantitative characterization of glomerular fibrosis with magnetic resonance imaging: a feasibility study in a rat glomerulonephritis model

Glomerular fibrosis occurs in early stage of multiple renal diseases, including hypertensive and diabetic nephropathy. Conventional assessment of glomerular fibrosis relies on kidney biopsy, which is invasive and does not reflect physiologic aspects such as blood perfusion. In this study, we sought to assess potential changes of cortical perfusion and microstructure at different degrees of glomerular fibrosis using magnetic resonance imaging (MRI). Methods: A rat model of glomerular fibrosis was induced by injecting anti-Thy-1 monoclonal antibody OX-7 to promote mesangial extracellular matrix proliferation. For six rats on day 5 and five rats on day 12 after the induction, we measured renal cortical perfusion and spin-spin relaxation time (T2) in a 3-Tesla MRI scanner. T2 reflects tissue micro-structural changes. Glomerular-fibrosis severity was evaluated by histological analysis and proteinuria. Four rats without fibrosis were included as controls. Results: In the control rats, periodic acid-Schiff (PAS)...