Nonlinear encoding scheme design for gradient-free projection imaging in an inhomogeneous Bo at low-field

Abstract

Gradient-free imaging at low-fields can significantly reduce the cost of and increase access to MRI devices. Here we propose to exploit the Bloch-Siegert shift effect to perform gradient-free, RF spatial encoding at 24mT. We have developed a simulation algorithm that designs various nonlinear encoding schemes and evaluates their performance through image reconstruction. Our results indicate that this technique is tolerant to noise and B0 inhomogeneities; this is an important step towards demonstrating the feasibility of performing low-field imaging with nonlinear RF spatial encoding using the Bloch-Siegert shift.