Realistic Analytical Phantoms for Parallel Magnetic Resonance Imaging

Matthieu Guerquin-Kern (1) , Laurent Lejeune , Klaas P Pruessmann (2) , Michael Unser (1)

1 Biomedical Imaging Group [Lausanne]
2 IBT - Institute for Biomedical Engineering [ETH Zürich]

The quantitative validation of reconstruction algorithms requires reliable data. Rasterized simulations are popular but they are tainted by an aliasing component that impacts the assessment of the performance of reconstruction. We introduce analytical simulation tools that are suited to parallel magnetic resonance imaging and allow one to build realistic phantoms. The proposed phantoms are composed of ellipses and regions with piecewise-polynomial boundaries, including spline contours, Bézier contours, and polygons. In addition, they take the channel sensitivity into account, for which we investigate two possible models. Our analytical formulations provide well-defined data in both the spatial and k-space domains. Our main contribution is the closed-form determination of the Fourier transforms that are involved. Experiments validate the proposed implementation. In a typical parallel MRI reconstruction experiment, we quantify the bias in the overly optimistic results obtained with rasterized simulations—the inverse-crime situation. We provide a package that implements the different simulations and provide tools to guide the design of realistic phantoms.

Mots clés: MRI; Fourier analytical simulation; Shepp- Logan; inverse crime

Domaines: Traitement du signal et de l'image [eess.SP]; Imagerie médicale

Matthieu Guerquin-Kern, Laurent Lejeune, Klaas P Pruessmann, Michael Unser. Realistic Analytical Phantoms for Parallel Magnetic Resonance Imaging. IEEE Transactions on Medical Imaging, 2012, 31 (3), pp.626 - 636. ⟨10.1109/TMI.2011.2174158⟩. ⟨hal-01814155⟩