Diffusion- and T2-weighted MR Imaging of the Liver: Effect of Intravenous Administration of Gadoxetic Acid Disodium

Purpose: We evaluated the effect of intravenous administration of gadoxetic acid disodiurn to hepatic lesions and liver parenchyma on T-2-weighted (T2WI) and diffusion-weighted imaging (DWI). Materials and Methods: One hundred and one consecutive patients with 259 hepatic lesions underwent T2WI and DWI (b-values of 500 and 1000 s/mm(2)) before and after gadoxetic acid administration. We compared the ratio of signal intensity (SIR) of the liver parenchyma and hepatic lesions, the ratio of contrast intensity of the lesion to the liver (CIR), the apparent diffusion coefficients (ADCs) of the liver and lesions, and lesion detectability between pre- and post-contrast images. Results: SIRs, CIRs, and ADC of focal hepatic lesions were comparable on pre- and post-contrast images, and lesion detectability did not differ significantly between pre- and post-contrast T2WI and DWI. The SIRs of the liver parenchyma were significantly lower on post-contrast DWI (1.4 +/- 0.68 [b = 500 s/mm(2)] and 1.71 +/- 0.67 [b = 1000 s/mm(2)]) than pre-contrast images (1.89 +/- 0.68 [b = 500 s/mm(2)] and 2.26 +/- 0.78 [b = 1000 s/mm(2)]) (P < 0.001). ADCs of the liver parenchyma were also significantly decreased on post-contrast DWI (0.77 +/- 0.32 mm(2)/s) than pre-contrast images (0.64 +/- 0.33 mm(2)/s) (P = 0.001). Conclusion: T2WI and DWI after administration of gadoxetic acid are feasible and do not compromise the SIR, CIR, and ADC of focal hepatic lesions. However, the signal intensity of DWI and ADC value of the liver parenchyma were decreased on gadoxetic acidenhanced hepatocyte phase images.