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-analysis of an existing dataset to determine if 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 vs. 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−ktransDC) 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 against simulated data suggests contrast leakage occurs across the aneurysm wall.