COMPARISON OF UNENHANCED AND GADOXETATE DISODIUM-ENHANCED SPIN-ECHO MAGNETIC-RESONANCE-IMAGING FOR THE DETECTION OF EXPERIMENTAL HEPATOCELLULAR-CARCINOMA IN THE RAT

RATIONALE AND OBJECTIVES. The authors compare the potential value of u nenhanced and gadoxetate disodium-enhanced spin-echo images for the de tection of hepatocellular carcinoma in a rat model. METHODS. Eleven ra ts with chemically induced hepatocellular carcinoma underwent unenhanc ed T2-weighted fast spin-echo imaging followed by T1-weighted spin-ech o imaging before and at 5 minutes, 30 minutes, 3 hours, 1 day, and 3 d ays after intravenous administration of 60 mu mol/kg gadoxetate disodi um at 4.7 tesla. Tumor and liver enhancement, and tumor-to-liver contr ast-to-noise (C/N) ratio were calculated. RESULTS. After gadoxetate di sodium administration, the tumors showed less enhancement than the liv er. Tumor-to-liver C/N ratio increased from 5.5 +/- 0.8% on unenhanced T1-weighted images to 12.9 +/- 2.4% on gadoxetate-enhanced T1-weighte d images (P = 0.02). However, the C/N ratio on unenhanced T2-weighted images (23.5 +/- 3.6%) remained higher than that on gadoxetate-enhance d T1-weighted images, a difference that is statistically significant ( P = 0.01). CONCLUSIONS. In the experimental setting of our study, the higher turner-to-liver C/N ratio on unenhanced T2-weighted spin-echo i mages suggests that unenhanced T2-weighted spin-echo images are superi or to gadoxetate disodium-enhanced T1-weighted spin-echo images for th e detection of hepatocellular carcinoma.