Fast Realistic MRI Simulations Based on Generalized Multi-Pool Exchange Tissue Model.

Fang Liu,Richard Kijowski,Alexey A Samsonov,Julia V Velikina,Walter F Block

doi:10.1109/tmi.2016.2620961

Fang Liu, Richard Kijowski + Show 3 more

Open Access

https://doi.org/10.1109/tmi.2016.2620961

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Abstract

We present MRiLab, a new comprehensive simulator for large-scale realistic MRI simulations on a regular PC equipped with a modern graphical processing unit (GPU). MRiLab combines realistic tissue modeling with numerical virtualization of an MRI system and scanning experiment to enable assessment of a broad range of MRI approaches including advanced quantitative MRI methods inferring microstructure on a sub-voxel level. A flexibl representation of tissue microstructure is achieved in MRiLab by employing the generalized tissue model with multiple exchanging water and macromolecular proton pools rather than a system of independent proton isochromats typically used in previous simulators. The computational power needed for simulation of the biologically relevant tissue models in large 3D objects is gained using parallelized execution on GPU. Three simulated and one actual MRI experiments were performed to demonstrate the ability of the new simulator to accommodate a wide variety of voxel composition scenarios and demonstrate detrimental effects of simplifie treatment of tissue micro-organization adapted in previous simulators. GPU execution allowed ∼200× improvement in computational speed over standard CPU. As a cross-platform, open-source, extensible environment for customizing virtual MRI experiments, MRiLab streamlines the development of new MRI methods, especially those aiming to infer quantitatively tissue composition and microstructure.

Highlights

Simulations constitute an essential part of the practice of magnetic resonance imaging (MRI) development as they allow for rapid prototyping and evaluation of MRI techniques in controlled conditions
To illustrate the importance of multi-pool modeling implemented in our simulator, we evaluated the effect of this simplificatio on MRI signal and myelin water fraction (MWF) quantification The simulations were performed using the full (Fig. 3a) and the simplifie models in a cylindrical object for multiple spin echo sequence
We presented a comprehensive, high-performance, open-source MRI simulation tool capable of realistic simulations of the whole MRI experiment with fl xible representation of tissues by multi-pool exchange models

Summary

Introduction

Simulations constitute an essential part of the practice of magnetic resonance imaging (MRI) development as they allow for rapid prototyping and evaluation of MRI techniques in controlled conditions. Over the years, increasing complexity of MRI systems, emergence of novel acquisition and reconstruction methods, and exploration of advanced MRI contrast mechanisms necessitated more realistic MRI simulations based on numerical modeling [1, 2]. This stimulated development of dedicated software solutions that take advantage of growing availability of high-performance computing to increase fidelit of MRI simulations. The developed software solutions have contributed to a notable progress toward more accurate simulations of MRI hardware and imaging processes in acceptable time, though several important limitations still exist

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