Hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide-enhanced magnetic resonance imaging in cirrhosis or chronic hepatitis: comparison of four magnetic resonance sequences for lesion conspicuity.
OBJECTIVE
The aim of this study was to determine the adequate MR sequence for the lesion conspicuity of hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide (SPIO)-enhanced MRI.


METHODS
SPIO-enhanced MRI was performed using a 1.5-T system. Among 25 patients with hypovascular hepatocellular nodules on contrast-enhanced dynamic CT (no early enhancement at arterial phase and hypoattenuation at equilibrium phase), 39 lesions with increased iron uptake on SPIO-enhanced MRI were evaluated. SPIO-enhanced MRI included (1) T1-weighted in-phase gradient recalled echo (GRE) images, (2) T2-weighted fast spin echo (FSE) images, (3) T2*-weighted GRE with moderate TE (7 ms) and (4) long TE (12 ms). The lesion-to-liver contrast-to-noise ratios of the hepatocellular nodule and the signal-to-noise ratio (SNR) of the hepatic parenchyma were calculated by one radiologist for a quantitative assessment. MR images were reviewed retrospectively by two independent radiologists to compare the subjective lesion conspicuity in each image set based on a four-point rating scale.


RESULTS
The mean lesion-to-liver contrast-to-noise ratios with T2*-weighted GRE with moderate TE (7 ms) was highest (5.79+/-3.71) and was significantly higher than those with T1-weighted, in-phase images (3.79+/-3.23, P<.01), T2-weighted images (2.72+/-1.52, P<.001) and T2*-weighted GRE with long TE (12 ms) (3.93+/-2.69, P<.05). The subjective rating of lesion conspicuity was best on the T2*-weighted GRE with moderate TE (7 ms), followed by that on the T2*-weighted GRE with moderate TE (7 ms; P<.05).


CONCLUSIONS
T2*-weighted GRE sequence with moderate TE (7 ms) showed high lesion-to-liver contrast-to-noise ratios in hepatocellular lesions with increased iron uptake on SPIO-enhanced MRI, indicating better lesion conspicuity of hypointense hepatocellular nodules in cirrhosis or chronic hepatitis.
Tanabe
Masahiro
M
Department of Radiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan. masa-ygc@umin.ac.jp
Ito
Katsuyoshi
K
Shimizu
Ayame
A
Fujita
Takeshi
T
Onoda
Hideko
H
Yamatogi
Shigenari
S
Washida
Yasuo
Y
Matsunaga
Naofumi
N
D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000378:metabolism; D002908:Chronic Disease; D003287:Contrast Media / Q000493:pharmacokinetics; D003911:Dextrans; D005260:Female; D052203:Ferrosoferric Oxide; D006505:Hepatitis / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007501:Iron / Q000493:pharmacokinetics; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000378:metabolism; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D010087:Oxides / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; C097921:ferumoxtran-10; D007501:Iron; D052203:Ferrosoferric Oxide