[Diagnostic role of magnetic resonance in the renal involvement in nocturnal paroxysmal hemoglobinuria].

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