Abstract #3916

Does R2* Increase or Decrease When Contrast Agent Extravasates? A Simulation Study.

Nicolas Pannetier^1,2, Clment Debacker^1,2, Franck Mauconduit^1,2, Thomas Christen^1,3, Emmanuel Luc Barbier^1,2

¹U836, INSERM, Grenoble, France; ²Grenoble Institut des Neurosciences, Universit Joseph Fourier, Grenoble, France; ³Department of Radiology, Stanford University, Stanford, CA, United States

Quantification of Dynamic Susceptibility Contrast MRI remains a challenge when contrast agent (CA) extravasates into the interstitium. Indeed, CA extravasation increases tissue R1 relaxation(signal enhancement) and competes with R2* increase (signal destruction) used to compute perfusion estimates. However, the consequences of CA extravasation on R2* are often overlooked. CA extravasation reduces the magnetic susceptibility difference at the intra-/extravascular interface and CA extravasation yields to the emergence of magnetic susceptibility differences at the interfaces between cells and interstitium.In this study, we evaluated these two competing R2* effects in case of blood-brain barrier permeability using numerical simulations for various porosities and cell sizes.