Paroxysmal nocturnal hemoglobinuria: MR findings.
OBJECTIVE
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic disorder, characterized by hemosiderin deposition in the proximal renal tubules.


METHODS
We examined six cases of PNH with MRI including gradient echo imaging.


RESULTS
On T2- and T2*-weighted imaging a characteristic hypointense pattern was noted in five of six patients with PNH. The extent of the hypointense area roughly correlated with the time elapsed from the latest hemolytic attack.


CONCLUSIONS
T2*-weighted imaging (gradient echo imaging) is superior to T2-weighted imaging in the detection of hemosiderin in the renal cortex because of the higher sensitivity to magnetic susceptibility effect and shorter examination times. On the other hand, reversal of the normal cortical-to-medullary intensity ratio on T1-weighted imaging was not seen in our cases in which we used echo delay times short enough to neglect T2 effects.
Department of Radiology, University of Tsukuba, Ibaraki, Japan.
Y O
YO
Tanaka
I
I
Anno
Y
Y
Itai
T
T
Abe
D000368:Aged; D005260:Female; D006457:Hemoglobinuria, Paroxysmal / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007668:Kidney / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged