Effect of superparamagnetic iron oxide on tumor-to-liver contrast at T2*-weighted gradient-echo MRI: comparison between 3.0T and 1.5T MR systems.
OBJECTIVE
To compare 3.0T and 1.5T MR systems in terms of the effect of superparamagnetic iron oxide (SPIO) on tumor-to-liver contrast in T2*-weighted gradient-echo MRI.


METHODS
SPIO-enhanced gradient-echo MR images of the liver with four different TEs (3, 5.3, 6.5, and 8.5 msec) were obtained by means of 1.5T and 3.0T systems. Quantitative analyses of relative signal intensities (SIs) and relative tumor contrast and qualitative analyses of image quality and lesion conspicuity of the liver were performed in 22 patients, 16 of whom had malignant liver tumors.


RESULTS
With both 1.5T and 3.0T, at TE=8.4 msec, the relative SI of liver and relative tumor contrast were significantly (P<0.01) lower and higher, respectively, than that for any of the other TEs. There were no significant differences in the relative SI of the liver, relative tumor contrast, image quality, and tumor conspicuity for the same TE between the 1.5T and 3.0T systems.


CONCLUSIONS
Our results showed that the effect of SPIO on tumor-to-liver contrast at T2*-weighted gradient-echo imaging was similar for the 1.5T and 3.0T systems, and that the 8.4-msec TE was optimal of the four TEs used in this study at 3.0T.
Kim
Tonsok
T
Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan. kim@radiol.med.osaka-u.ac.jp
Murakami
Takamichi
T
Hori
Masatoshi
M
Onishi
Hiromitsu
H
Tomoda
Kaname
K
Nakamura
Hironobu
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000175:diagnosis / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology; D018281:Cholangiocarcinoma / Q000175:diagnosis / Q000473:pathology; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000473:pathology; D003287:Contrast Media; D003911:Dextrans; D003937:Diagnosis, Differential; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007501:Iron; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide