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

Purpose: To 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.

Methods: Twenty-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 (D-slow), microperfusion (D-fast), its fraction (f(fast)), wash-in-rate (R-early) and late-enhancement-rate (R-late) 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 R-early for parenchyma 2) to post-contrast IVIM substantiated with simulations 3) between low and high R-late per lesion type.

Results: D-fast and f(fast) increased (P <0.001) with 25.6% and 33.8% between low and high R-early of Gd-EOB-DTPA. New decreased (-15.0%; P <0.001) with increasing R-early. Gd-DOTA demonstrated similar observations. f(fast) (+10%; P <0.001) and D-fast (+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) D-fast and f(fast) increased (P <0.001) with increasing R-late, whereas for hepatocellular carcinoma (n = 4) and adenoma (n = 7) no differences were found.

Conclusion: Microperfusion 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. (C) 2016 Elsevier Inc. All rights reserved.