Method and device for phase-sensitive flow measurement by a magnetic resonance
AssigneeSiemens Aktiengesellschaft
InventorsAndreas Greiser, Edgar Mueller, Michael Zenge
Life of this patent
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Abstract
In a method and a device for phase-sensitive flow measurement of a volume segment of an examination subject in a measurement system, the volume segment is divided into multiple partial volume segments and the following steps are executed repeatedly until the volume segment has been completely measured: movement of a table such that a center of one of the partial volume segments to be measured essentially corresponds to the isocenter of the magnetic resonance system, and implementation of the phase-sensitive flow measurement for the partial volume segment to be measured while the center of the partial volume segment essentially corresponds to the isocenter.
Claims17
A method for phase-sensitive flow measurement of a volume segment of an examination subject by magnetic resonance imaging, comprising the steps of:
- in a computerized control system that operates a magnetic resonance data acquisition unit, having an isocenter, in which an examination subject containing a volume segment from which magnetic resonance data are to be acquired is located, dividing said volume segment into a plurality of partial volume segments, each having a center, to cause a thickness of each of said partial volume segments, in a direction of a basic magnetic field generated by the data acquisition unit, to not exceed 10 cm;
- operating said magnetic resonance data acquisition unit from said computerized control unit to repeatedly execute the following steps for each of said partial volume segments until magnetic resonance data have been acquired from an entirety of said volume segment:
- moving a table, on which the examination subject is located, through the data acquisition unit to cause the center of one of said partial volume segments, from which magnetic resonance data are to be acquired, to substantially coincide with the isocenter of the data acquisition unit,
- implementing a phase-sensitive flow measurement, in which gradient magnetic fields are activated, in order to acquire phase-sensitive magnetic resonance data representing a flow of nuclear spins in said examination volume from an entirety of said one of said partial volume segments while movement of said table is temporarily ceased in order to maintain said center of said one of said partial volume segments substantially coincident with the isocenter of the data acquisition unit during acquisition of all of said magnetic resonance data from said entirety of said one of said partial volume segments, and
- said thickness of each of said partial volume segments not exceeding 10 cm reducing, when said center of said one of said partial volume segments is substantially coincident with the isocenter of the data acquisition unit, effects of any non-linearities of said gradient magnetic fields, and any eddy currents produced by said gradient magnetic fields, on the acquired magnetic resonance data.
A device for phase-sensitive flow measurement of a volume segment of an examination subject by magnetic resonance imaging, comprising the steps of:
- a computerized control system configured to operate a magnetic resonance data acquisition unit, having an isocenter, in which an examination subject containing a volume segment from which magnetic resonance data are to be acquired is located, said computerized control system being configured to divide said volume segment into a plurality of partial volume segments, each having a center, to cause a thickness of each of said partial volume segments, in a direction of a basic magnetic field generated by the data acquisition unit, to not exceed 10 cm;
- said computerized control system being configured to operate said magnetic resonance data acquisition unit from said computerized control unit to repeatedly execute the following steps for each of said partial volume segments until magnetic resonance data have been acquired from an entirety of said volume segment:
- moving a table, on which the examination subject is located, through the data acquisition unit to cause the center of one of said partial volume segments, from which magnetic resonance data are to be acquired, to substantially coincide with the isocenter of the data acquisition unit,
- implement a phase-sensitive flow measurement, in which gradient magnetic fields are activated, in order to acquire phase-sensitive magnetic resonance data representing a flow of nuclear spins in said examination volume from one entirely of said one of said partial volume segments while movement of said table is temporarily ceased in order to maintain said center of said one of said partial volume segments substantially coincident with the isocenter of the data acquisition unit during acquisition of all of said magnetic resonance data from said entirety of said one of said partial volume segments, and
- said thickness of each of said partial volume segments not exceeding 10 cm reducing, when said center of said one of said partial volume segments is substantially coincident with the isocenter of the data acquisition unit, effects of any non-linearities of said gradient magnetic fields, and any eddy currents produced by said gradient magnetic fields, on the acquired magnetic resonance data.
A non-transitory computer-readable storage medium encoded with programming instructions, said storage medium being loaded into a computerized control system of a magnetic resonance data acquisition unit having an isocenter and comprising a movable patient table that is movable through said data acquisition unit, said patient table having an examination subject thereon containing a volume segment from which magnetic resonance data are to be acquired, said programming instructions causing said computerized control unit to:
- divide said volume segment into a plurality of partial volume segments, each having a center to cause a thickness of each of said partial volume segments, in a direction of a basic magnetic field generated by the data acquisition unit, to not exceed 10 cm;
- operate said magnetic resonance data acquisition unit to repeatedly execute the following steps for each of said partial volume segments until magnetic resonance data have been acquired from an entirety of said volume segment:
- move the table, on which the examination subject is located, through the data acquisition unit to cause the center of one of said partial volume segments, from which magnetic resonance data are to be acquired, to substantially coincide with the isocenter of the data acquisition unit, and
- implement a phase-sensitive flow measurement, in which gradient magnetic fields are activated, in order to acquire phase-sensitive magnetic resonance data representing a flow of nuclear spins in said examination volume from an entirety of said one of said partial volume segments while movement of said table is temporarily ceased in order to maintain said center of said one of said partial volume segments substantially coincident with the isocenter of the data acquisition unit during acquisition of all of said magnetic resonance data from said entirety of said one of said partial volume segments, and
- said thickness of each of said partial volume segments not exceeding 10 cm reducing, when said center of said one of said partial volume segments is substantially coincident with the isocenter of the data acquisition unit, effects of any non-linearities of said gradient magnetic fields, and any eddy currents produced by said gradient magnetic fields, on the acquired magnetic resonance data.
Dependencies are inferred from the claim text.