Estimation of the phase gradient in MIR

Abstract

Images acquired from magnetic resonance imaging scanners take complex values. The images can be broken into two distinct types of images: magnitude images and phase maps. Magnitude images display structural information while phase maps are sensitive to magnetic field inhomogeneities and changes in temperature. However, phase maps are discontinuous and a process known as phase unwrapping is needed to remove the discontinuities in the phase map. In this work, a new two dimensional phase unwrapping algorithm is proposed and results from the proposed algorithm are compared with standard phase unwrapping algorithms. Extensions to the proposed phase unwrapping algorithm are then considered, the proposed two-dimensional phase unwrapping algorithm is modified and a new thermometry algorithm is presented. Finally, the quantification of contrast agents based on superparamag- netic iron oxide (SPIO) nanoparticles is discussed and a new SPIO quantification algorithm is proposed.