Diffusion-weighted MR imaging of liver on 3.0-Tesla system: effect of intravenous administration of gadoxetic acid disodium.

Abstract

OBJECTIVE: To determine whether intravenous administration of gadoxetic acid disodium (Gd-EOB-DTPA) affects lesion conspicuity and apparent diffusion coefficient (ADCs) in diffusion-weighted imaging (DWI) for hepatic magnetic resonance imaging (MRI) at 3.0 T.

METHODS: Thirty-four patients with 50 focal hepatic lesions (18 hepatocellular carcinomas, 12 metastases, 1 cholangiocarcinoma, 7 haemangiomas, 12 cysts) underwent DWI at 3.0 T before and after administration of Gd-EOB-DTPA. Non-breath-hold DWI was performed with b values of 0, 200, 400 and 800 s/mm(2). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of each lesion, and ADCs of the liver and lesion were calculated for unenhanced and enhanced images. Statistical differences between unenhanced and enhanced data were assessed.

RESULTS: SNRs and ADCs of the liver on enhanced images were significantly lower than on unenhanced images. On DW images at b = 200 s/mm(2), CNRs of malignant and overall lesions were significantly higher on enhanced than on unenhanced images. CNRs of focal lesions tended to be higher, especially in malignant lesions, on DW images at b = 0 and 400 s/mm(2), but without reaching statistical significance. ADCs of focal hepatic lesions were not significantly different before and after administration of contrast agent.

CONCLUSION: DWI after Gd-EOB-DTPA administration can be used as a substitute for unenhanced DWI at 3.0 T without compromising CNR and ADC of focal hepatic lesions.