Infiltrative hepatocellular carcinoma on gadoxetic acid-enhanced and diffusion-weighted MRI at 3.0T

To determine imaging features of infiltrative hepatocellular carcinoma (HCC) on 3T magnetic resonance imaging (MRI) including gadoxetic acid-enhanced and diffusion-weighted imaging (DWI).

Eighteen patients with infiltrative HCC underwent liver MRI that consisted of T1- and T2-weighted image (T2WI), gadoxetic acid-enhanced arterial, portal, 3-min late and 20-min hepatobiliary phase (HBP), and DWI. Two reviewers evaluated in consensus tumor characteristics and lesion conspicuity using a 4-point scale. The tumor-to-liver contrast ratio was also measured.

Most of the tumors (n = 16, 88.9%) were seen as irregular permeative masses (4.0-23.0 cm, mean 10.5 cm in diameter) and the remaining two as poorly defined amorphous infiltration among thrombosed portal veins. Internal reticulation within the tumor was characteristic and was most frequently observed on 3-min late phase (n = 18), followed by HBP (n = 15). Tumor conspicuity and tumor-to-liver contrast ratio was highest with b-800 DWI, which was significantly higher than those of other images (P < 0.05).

DWI provides the highest conspicuity for infiltrative HCC compared to unenhanced T1- and T2WI and gadoxetic acid-enhanced MRI. The gadoxetic acid-enhanced 3-min late image is useful in characterizing infiltrative HCC, as it clearly depicts internal reticulation in all tumors.