Enhancement of liver hemangiomas on T1-weighted MR SE images by superparamagnetic iron oxide particles.
OBJECTIVE
Superparamagnetic iron oxide (SPIO) particles are phagocytosed by cells of the macrophage-monocytic phagocytic system. They are usually used in MRI as a negative contrast agent, because of their strong T2* effect, to improve detection of tumors in the liver and spleen. However, they also have a potent T1 relaxivity. In the current study, we describe this T1 effect in liver hemangiomas.


METHODS
Twelve patients (nine women and three men, aged from 38 to 76 years) with liver hemangiomas were examined by means of MRI at 1.5 T before and after intravenous administration of SPIO particles at a dose of 15 mumol Fe/kg body wt. Signal intensity was measured from regions of interest.


RESULTS
Whereas on postcontrast T2-weighted SE images the hemangiomas showed on average a signal drop of 20% (p = 0.011) and 49% (p = 0.001) (first and second echo, respectively), their signal increased by 106% (p = 0.001) on postcontrast T1-weighted SE images.


CONCLUSIONS
The T1 effect (signal enhancement) we observed in liver hemangiomas after infusion of SPIO particles could prove to be a useful new diagnostic feature that would help characterize these common lesions and differentiate them from other liver tumors.
Department of Radiology, University Hospital of Geneva, Switzerland.
C
C
Grangier
J
J
Tourniaire
G
G
Mentha
R
R
Schiau
N
N
Howarth
A
A
Chachuat
M
M
Grossholz
F
F
Terrier
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000473:pathology; D003287:Contrast Media / Q000008:administration & dosage; D003911:Dextrans; D005260:Female; D052203:Ferrosoferric Oxide; D006391:Hemangioma / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D007501:Iron / Q000008:administration & dosage; D008099:Liver / Q000473:pathology; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides / Q000008:administration & dosage; D013535:Suspensions
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D013535:Suspensions; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide