Purpose: The purpose of this study was to investigate the diffusional transport of contrast agent and its effects on kinetic modeling of dynamic contrast enhanced (DCE) images.
Methods: We performed simulations of our diffusion-compensated model and compared these results to human intracranial aneurysms (IAs). We derive an easy-to-use parameterization of diffusional effects that can provide an accurate estimate of diffusion corrected contrast agent leakage rates (ktrans ). Finally, we performed re-ansalysis of an existing data set to determine whether diffusion-corrected kinetic parameters improve the identification of high-risk IAs, thereby providing a new MRI-based imaging metric of IA stability based on wall integrity.
Results: Probability distributions of simulated versus measured data show contrast leakage away from the aneurysm wall. Parameterization of diffusional effects on ktrans showed high correlation with long-chain methods in both surrounding tissue and near the aneurysm wall (r2 = 0.91 and r2 = 0.90, respectively). Finally, size, ktrans , and ( ktrans-kDCtrans) showed significant univariate relationships with rupture risk (P < 0.05).
Conclusions: We report the first evidence of diffusion-compensated permeability modeling in intracranial aneurysms and propose a parameterization of diffusional effects on ktrans . Furthermore, a comparison of measured versus simulated data suggests that contrast leakage occurs across the aneurysm wall. Magn Reson Med 78:2388-2398, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
Keywords: Tofts model; aneurysm; contrast leakage; rupture risk.
© 2017 International Society for Magnetic Resonance in Medicine.