Research Training Group 2154 - Materials for Brain

Project 2b: Isil Unal

Aneurysm flow imaging using Arterial Spin Labelling techniques (MRI)

Cerebral aneurysm is a life-threatening disease when a rupture occurs due to various cases in brain arteries.  Among the specific hemodynamic factors leading to aneurysm rupture are the blood flow rate (flow rate), blood pressure and Wall Shear Stress, which is formed due to flow velocity near the vessel wall. Therefore, endovascular treatments try to change the hemodynamic properties within the aneurysm as a method of preventing aneurysmal rupture. Various methods are available for the control of these hemodynamic parameters such as vascular clips, coils and flow diverters (FDs).  

Project P2b collaborates with the Project P2a “Thin film flow-diverter stents based on super elastic shape memory alloys”. The aim of this project is to design and manufacture a stent for healing of the aneurysm by changing the flow parameters of the blood.  It is important to measure the change of hemodynamic parameters after implantation of the stent. Project P2b aims to measure the hemodynamic parameters in the flow model which will be developed to mimic the cerebral artery, by using the Arterial Spin Labeling MRI technique before and after the implantation of stent which will be developed in 2nd generation P2a.

In order to develop new flow model, aneurysm data sets are obtained using high-resolution angiographic 3D MRA and used to produce 3D printed models with high elasticity materials to mimics the real artery and facilitate stent implantation.  Hemodynamic parameters are measured (with and without stent) in flow models  with advanced flow-sensitive MR angiographic techniques such as Arterial Spin Labelling MRI and the results are verified with conventional angiographic techniques  (2D phase-contrast MRA, CTA, DSA).