Patent ID: 7843195
Filing Date: 2010-11-30
Classification: G01R

Abstract:
1. A method for determining a spatial distribution of magnetic resonance signals from a predetermined imaging region that is completely covered by N MSEM regions within a volume under examination of a magnetic resonance apparatus, where N≧1, the method comprising the steps of: a) executing a preparatory step in which a spatial encoding scheme P with M encoding steps, M≧1, is defined for spatial encoding in L spatial dimensions within the imaging region, wherein, for phase encoding of the N MSEM regions, a phase encoding scheme A with I phase encoding steps is defined, where I≧N≧1, and for each of these phase encoding steps according to phase encoding scheme A, a spatial, complex excitation pattern of a transverse magnetization of nuclear spins is defined, wherein for amplitude modulation, amplitudes within the imaging region are set to be identical for each phase encoding step according to a predetermined distribution, for spatial selection, the amplitudes outside the imaging region are set to zero and, for phase modulation, the phases within the MSEM regions of the imaging region are set according to the defined phase encoding scheme A, wherein a same phase is defined at all locations within a single MSEM region, and a progression over time of the amplitude and phase of RF pulses to be irradiated to excite the nuclear spins is calculated for each defined complex excitation pattern of the phase encoding steps according to phase encoding scheme A and for each transmission element of transmission antenna equipment; b) carrying out an execution step in which, during each encoding step of the spatial encoding scheme P, the nuclear spins are excited in the volume under examination by at least one RF pulse using RF transmitter antenna equipment having at least one transmitter element, wherein, after this RF excitation, spatial encoding according to the spatial encoding scheme P by means of additional magnetic fields of a global and/or local gradient system that are variable over time and space is performed, the spatial encoding being performed in at least one spatial dimension by means of a local gradient system and being unique within each of the N non-overlapping MSEM regions, but not for multiple MSEM regions and not in an entire volume under examination, wherein the spatial encoding performed by a global gradient system with respect to each dimension to be mapped therewith is unique in the entire volume under examination, and magnetic resonance signals generated by excited nuclear spins are acquired by means of RF receiving antenna equipment with at least one receiver element, wherein each encoding step that is executed according to spatial encoding scheme P is performed I times according to phase encoding scheme A, wherein, for excitation of the nuclear spins for each phase encoding step according to phase encoding scheme A, an RF pulse or RF pulses calculated for this are applied so that selection of the imaging region as well as amplitude modulation and phase encoding within the imaging region according to phase encoding scheme A are performed during excitation of the nuclear spins, wherein for the case of a single phase encoding step, that is, I=N=1, gradients are also applied simultaneously with the RF pulse irradiation; c) executing a reconstruction step in which one or more spatial distributions of magnetic resonance signals or quantities derived from them are calculated from magnetic resonance signals acquired in all encoding steps according to the spatial encoding scheme P, a spatial distribution of the magnetic resonance signals being determined separately for each of the N MSEM regions; and d) carrying out a visualization step in which results of reconstruction and/or one or more quantities derived from them are stored and/or visualized, wherein results of the reconstruction are visualized separately for each of the N MSEM regions and/or integrated with reference to a shared reference system.