Magnetic resonance in renal damage due to paroxysmal nocturnal haemoglobinuria

Paroxysmal nocturnal haemoglobinuria or Machiafava-Micheli disease is an ac quired clonal stem cell disorder characterized by defective haematopoiesis, which results in an increased sensitivity of the erythrocytes to complemen t-mediated intravascular haemolysis. Renal damage is rare but it can lead t o chronic renal failure. Micro-infarctions due to repeated episodes of micr ovascular thrombosis and cortical haemosiderosis are thought to be the main contributors to the development of chronic renal failure in paroxysmal noc turnal haemoglobinuria. Magnetic resonance imaging provides characteristic images of the kidney. We describe a patient with cortical haemosiderosis an d show the magnetic resonance features.