Patent ID: 8791700
Filing Date: 2014-07-29
Classification: G01R

Abstract:
1. A method of magnetic resonance (=MR) with spatial encoding to generate an image or spectroscopic data of an object of investigation inside an MR apparatus, the method comprising the steps of: (a) selecting a volume of interest within the object of investigation; (b) applying an RF pulse to generate a transverse magnetization within the object of investigation; (c) preparing a nonlinear phase distribution of the transverse magnetization within the object of investigation by application of spatially encoding magnetic fields (SEMs), the SEMs comprising a nonlinear gradient field or a combination of linear and nonlinear gradient fields, wherein an object location-spatial frequency correspondence is thereby generated; (d) effecting primary spatial encoding through application of SEMs to acquire particular spatial frequencies predetermined by the encoding process and the k-space trajectory, thereby constraining sampled Fourier components, wherein sampling is carried out for a fixed period of time and spatial frequencies greater than a maximum encoded spatial frequency are thereby not recovered, wherein preparation of the nonlinear phase distribution in step (c) and primary spatial encoding in step (d) comprise applying a sequence of at least two SEMs, at least one of which contains a nonlinear field gradient and at least two of which have different field geometries, wherein the sequence of the at least two SEMs is applied at a point in time from and including excitation of the object of investigation in step (b) up to and including a recording of MR signals, thereby introducing a temporal shift of signals arising from spatially different locations within the selected volume of interest and thereby introducing a shift of local spatial frequency components, wherein a sampling window for recording of the respective MR signals is set, such that signals originating from the volume of interest are recorded and undesired signals originating from outside the volume of interest are suppressed; and (e) recording MR signals originating from the object of investigation.