Abstract #0482

A Performance Measure for MRI with Nonlinear Encoding Fields

Kelvin Layton^1,2, Mark Morelande¹, Peter Mark Farrell¹, Bill Moran¹, Leigh Andrea Johnston^1,3

¹Electrical & Electronic Engineering, The University of Melbourne, Melbourne, Australia; ²NICTA Victorian Research Laboratory, Melbourne, Australia; ³Howard Florey Institute, Australia

Magnetic fields that varying nonlinearly across the field-of-view have recently been employed in parallel imaging to develop novel encoding schemes such as PatLoc and O-Space. A result of nonlinear encoding is that the quality of the image will vary across pixels. Since PatLoc satisfies certain properties, an expression for the spatially varying SNR can be derived analytically. However, no such expression is available for other schemes that are fundamentally different to PatLoc, such as O-Space imaging. In this work, we develop a simple metric to quantify the spatially varying performance, which is computationally efficient and applicable to arbitrary encoding schemes.