Does MRI trump pathology? A new era for staging and monitoring of kidney fibrosis

Renal fibrosis, which is characterized by the progressive deposition and accumulation of excess extracellular matrix,1 is a strong predictor of progression in chronic kidney disease (CKD).2,3 Recent advances in diagnostic imaging techniques, including ultrasonography and noncontrast-enhanced magnetic resonance imaging (MRI), have shown promise for noninvasive assessment of renal fibrosis both in animals and humans.4 However, the specificity of these techniques is controversial, because they indirectly assess renal fibrosis by evaluating the impact on mechanical or molecular properties of the tissue, and in the case of functional MRI, on kidney function.