What does renal iron deposition look like on MRI, and what are its major causes?
Renal cortical iron deposition is most commonly caused by intravascular hemolysis secondary to a malfunctioning prosthetic cardiac valve, paroxysmal nocturnal hemoglobinuria (PNH), or sickle cell disease. Renal medullary iron deposition, which is much less common, may be secondary to hemorrhagic fever with renal syndrome (HFRS) or renal vein thrombosis.
On MRI, iron deposition leads to decreased T1-weighted and T2-weighted signal intensity of the kidneys, which is particularly accentuated on in-phase T1-weighted MR images and most often involves the renal cortices.
