Assessment of the link between quantitative biexponential diffusion-weighted imaging and contrast-enhanced MRI in the liver

Abstract

PurposeTo investigate if intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) can be linked to contrast-enhanced (CE-)MRI in liver parenchyma and liver lesions. MethodsTwenty-five patients underwent IVIM-DWI followed by multiphase CE-MRI using Gd-EOB-DTPA (n=20) or Gd-DOTA (n=5) concluded with IVIM-DWI. Diffusion (Dslow), microperfusion (Dfast), its fraction (ffast), wash-in-rate (Rearly) and late-enhancement-rate (Rlate) of Gd-EOB-DTPA were calculated voxel-wise for the liver. Parenchyma and lesions were segmented. Pre-contrast IVIM was compared 1) between low, medium and high Rearly for parenchyma 2) to post-contrast IVIM substantiated with simulations 3) between low and high Rlate per lesion type. ResultsDfast and ffast increased (P<0.001) with 25.6% and 33.8% between low and high Rearly of Gd-EOB-DTPA. Dslow decreased (−15.0%; P<0.001) with increasing Rearly. Gd-DOTA demonstrated similar observations. ffast (+10%; P<0.001) and Dfast (+6.6%; P<0.001) increased after Gd-EOB-DTPA, while decreasing after Gd-DOTA (−4.2% and −5.7%, P<0.001) and were confirmed by simulations. For focal nodular hyperplasia lesions (n=5) Dfast and ffast increased (P<0.001) with increasing Rlate, whereas for hepatocellular carcinoma (n=4) and adenoma (n=7) no differences were found. ConclusionMicroperfusion measured by IVIM reflects perfusion in a way resembling CE-MRI. Also IVIM separated intra- and extracellular MR contrast media. This underlines the potential of IVIM in quantitative liver imaging.