Section: New Results

Diffusion MRI

Jing-RebeccaLi, HoussemHaddar, SimonaSchiavi ,Khieu VanNguyen,GabrielleFournet

Diffusion Magnetic Resonance Imaging (DMRI) is a promising tool to obtain useful information on microscopic structure and has been extensively applied to biological tissues.

We obtained the following results.

• We derived using homogenization techniques a model of the time-dependent “apparent diffusion coefficient”(ADC) that is valid at a wide range of diffusion times. The ADC is a very important experimental quantity measured by diffusion MRI in biological tissues. This work resulted in one submitted article to a mathematical journal and we are preparing an article for a physics journal.

• We analyzed a dMRI model called the Karger model that is valid at long diffusion times. This resulted in one submitted article to a mathematical journal.

• We acquired dMRI data of the nerve cells of the Aplysia Californica at the high field brain MRI center Neurospin. This data is useful because the nerve cells are bigger than mammal neurons and so it is easier to obtain segmented geometrical information about these cells for model validation.

• We participated in the data analysis and numerical simulation of a MR imaging method to measure blood flow in micro-vessels in the brain. This resulted in a submitted article to a MRI journal.