Diffusion-compensated tofts model suggests contrast leakage through aneurysm wall.
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.
['Cantrell|Charles G|CG|', 'Vakil|Parmede|P|', 'Jeong|Yong|Y|', 'Ansari|Sameer A|SA|', 'Carroll|Timothy J|TJ|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D000783:Aneurysm D003198:Computer Simulation D003287:Contrast Media D038524:Diffusion Magnetic Resonance Imaging D005260:Female D006801:Humans D007091:Image Processing, Computer-Assisted D002532:Intracranial Aneurysm D007700:Kinetics D008297:Male D008875:Middle Aged D015233:Models, Statistical D015999:Multivariate Analysis D010539:Permeability D010865:Pilot Projects D018401:Sample Size D012984:Software
Tofts model contrast leakage aneurysm rupture risk