Distinguishing liver haemangiomas from metastatic tumours using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced diffusion-weighted imaging at 1.5T MRI.

INTRODUCTION: The aim of this study to evaluate the effectiveness of enhanced diffusion-weighted imaging (DWI) for distinguishing liver haemangiomas from metastatic tumours (mets).

METHODS: This study included 23 patients with 27 haemangiomas and 26 patients with 46 mets. Breath-holding diffusion-weighted imaging (DWI) (b-values of 0, 50, 100, 150, 200, 400 and 800 s/mm2 ) were obtained before and 20 min after injection of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). Lesion contrast-to-noise ratios (CNRs) were calculated. The data were processed using the bi-exponential model of intravoxel incoherent motion (IVIM). Receiver operating characteristic analysis was performed to compare the diagnostic performance when distinguishing haemangioma from mets.

RESULTS: The CNRs of haemangioma and mets at post-contrast enhancement increased. All IVIM parameters for liver haemangioma and mets showed no significant differences between pre- and post-contrast enhancement. The highest Az value of CNR and IVIM parameters occurred at a post-contrast b-value of 0 s/mm2 and true diffusion (D). The highest qualitative evaluation occurred at a b-value of 800 s/mm2 . The sensitivity and specificity, with a CNR of 100 or higher at a post-contrast b-value of 0 s/mm2 and considered to be haemangioma, were 89% and 67% (<10 mm, 91%, 77%) respectively. The sensitivity and specificity, when D was higher than 1.4 × 10-3 mm2 /s, were 74% and 83% (<10 mm, 64%, 77%) respectively. The sensitivity and specificity of qualitative evaluation by enhanced DWI were 74% and 76% (<10 mm, 64%, 80%) respectively.

CONCLUSIONS: The accuracy of the CNR was highest with b = 0; however, examination at high b-values had advantages in the qualitative evaluation of some small-size lesions.