LAUSR

AIM To evaluate the hepatobiliary phase (HBP) of liver magnetic resonance imaging (MRI) using gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid, and report a visual criterion based on the portal vein (PV), which can be used as a substitute for the quantitative liver-spleen contrast ratio (Q-LSC). MATERIALS AND METHODS In HBP images of 167 patients, a visual criterion was established based on the sufficient contrast between the liver parenchyma (LP) and PV. The Q-LSC was calculated for patients to assess whether the cut-off value of 1.5 was exceeded. The correlation between the signal intensities in the PV and tumours were determined and comparisons were made. The contrast between LP and the tumour was visually assessed with scores ranging from 1 to 3 defined as poor, fair, and good, respectively. The correlation between Q-LSC and quantitative liver-PV contrast ratio (Q-LPC) was also assessed. RESULTS The Q-LSC was <1.5 in all patients who did not meet the visual criterion. There was a strong correlation between the signal intensities in the PV and tumours (r=0.72), and no significant differences (p=0.99) were found between the signal intensities in PV and tumours by Wilcoxon's signed-rank test. Significant differences of all the combinations were found using Steel-Dwass multiple comparisons in the visual assessments of contrasts between LP and tumour. The correlation between Q-LSC and Q-LPC was strong (r=0.82). CONCLUSIONS The visual criterion based on the PV was suitable for the assessment of HBP images as a substitute for Q-LSC.