Parallel MRI: Principles and Image Reconstruction
Klaas Prüssmann, Institute for Biomedical Engineering, ETH, Zürich

Seminar • 05 February 2007 • BM 4.235

Abstract
Traditional MRI relies exclusively on the use of magnetic gradient fields for spatial signal encoding, leading to Fourier transform as the standard method of MR image reconstruction. This situation has changed fundamentally with the recent advent of so-called parallel MRI methods using arrays of signal detectors. Parallel aquisition enables faster imaging, however it does so at the expense of complications at the image reconstruction stage. The conceptual step from traditional to parallel MRI is marked by the transition from pure Fourier encoding to a more general hybrid encoding paradigm. As a consequence image reconstruction from array data requires more general concepts and algorithms. These will be discussed in detail, covering aspects such as the forward encoding formulation, the spatial response criterion, direct vs. iterative solving, noise propagation and control, and expansions towards perturbations other than reception characteristics.