MR OF THE KIDNEYS, LIVER, AND SPLEEN IN PAROXYSMAL-NOCTURNAL HEMOGLOBINURIA

The magnetic resonance (MR) findings in the liver, kidneys, and spleen in eight patients with paroxysmal nocturnal hemoglobinuria (PNH) were retrospectively reviewed to determine whether characteristic features could be demonstrated. Eight patients underwent abdominal MR examinat ions by gradient echo sequences (seven patients), spin-echo sequences (seven patients), and inversion recovery (one patient). Signal intensi ties of the kidneys, liver, and spleen were visually evaluated. Autops y and liver biopsy correlation were available in one case each. Renal signal intensity was decreased in all eight patients by either gradien t-echo or T2-weighted sequences and in the single inversion recovery s equence. Hepatic signal intensity was decreased in three of eight pati ents on spin- and gradient-echo images. Splenic signal intensity was d ecreased in three of eight patients on spin- and gradient-echo images, and in two of these was manifest as focal low signal spots (Gamna-Gan dy bodies). While the signal intensity in the renal cortex is typicall y decreased in patients with PNH, signal intensities in the liver and spleen are variable. Low signal intensity in the kidneys is due to hem osiderin deposition resulting from intravascular hemolysis, whereas lo w signal intensity in the liver or spleen may be due to either transfu sion siderosis, or as a consequence of hepatic or portal venous thromb osis.