A Generalized Finite Sized Dipole Model for Radar and Medical Imaging Part Ii: Near Field Formulation for Magnetic Resonance Imaging

Abstract

This paper presents a magnetic dipole-based formulation of near-electromagnetic field magnetic resonance imaging (MRI) problem and the development of an algorithm to perform correct medical diagnosis and image reconstruction from near-field measurements of radio frequency pulses in MRI. Magnetic resonance imaging uses electromagnetic signals to obtain high-resolution images of the human biological structure. This information is represented by color coded images, where the intensity of the color shows the concentration of the different constituent matter present. The constituent matter, have different chemical and electromagnetic properties and these properties define the nature of the electromagnetic signals radiated from these regions. The radiating regions in the biological structure are modeled by discrete magnetic dipoles and a more complete time-domain signal, encompassing the near electromagnetic fields. Using this new signal model, intensity inhomogeneity artifact in MR images is explained and corrected.