GRK 2154 - Materials for Brain

P2b: Aneurysm flow imaging using Arterial Spin Labeling techniques (MRI) (O. Jansen)

The project is a continuation of project P2b of the first PhD-generation, where aneurysms and their treatment with different devices, e.g. coils and stents, were imaged by using 4D flow MRI techniques at 1.5T, 3T and 7T. These techniques were applied in vitro, in vivo and investigated novel stent designs of project P2a.
MRI technique currently used is 4D flow phase-contrast angiography which yields excellent results but results in long scan times. As a new approach to dynamically map blood flow, Arterial Spin Labeling (ASL) will be used and further developed. The working group in Kiel has broad experience in performing this method and has its own patents. The goal is to implement a high-resolution angiographic technique based on ASL that allows for comprehensive aneurysm flow-imaging. The method will be cross-validated with 4D flow but also the gold standard of Digital Subtraction Angiography (DSA). These experiments are to be performed first in vitro on flow models as well as in volunteers and patients who have been treated in clinical routine. Additionally, artificial intelligence (AI) techniques should be used to increase the signal-intensity secondary.
The PhD-student will be integrated in a highly motivated team of MRI-physicists, will cooperate with physicians of the Department of Radiology and Neuroradiology, and will be trained in the methods developed by the first generation of the GRK 2154. This includes imaging with DSA and MRI from 1.5T–7T, and the manufacturing and use of patient-derived 3D printed models. The main task for the student will be to implement a high-resolution angiography MRI sequence based on ASL with high temporal resolution. To reach this goal, it will be necessary to perform pulse sequences programming, implementation of acceleration techniques such as compressed sensing, sparse imaging and AI techniques for reconstruction. The new sequences will be applied in vitro, in models and phantoms, and novel (intra-aneurysmal) stent designs (developed in Project P2a) will be tested.