Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Reexamination Certificate
2008-04-15
2008-04-15
Shrivastav, Brij (Department: 2859)
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
C324S307000, C324S318000
Reexamination Certificate
active
07358731
ABSTRACT:
The invention relates to a method for determination of spatial sensitivity profiles of RF transmit and/or receive coils (7, 8, 9) in an examination volume (17) of a magnetic resonance (MR) imaging device (1). In accordance with the method of the invention, nuclear magnetization is excited within the examination volume (17) by a sequence of RF pulses and switched magnetic field gradients, wherein the sequence comprises RF pulses with at least two different excitation flip angles. MR signals are acquired and processed so as to form at least two MR images, each corresponding to one of these flip angles. The spatial sensitivity profiles are then computed in the positions of the pixels or voxels of the MR images based upon the dependence of the pixel or voxel values on the respective flip angles. Alternatively, a plurality of instances of a sequence of RF pulses and switched magnetic field gradients is applied and MR signals are acquired, wherein a different combination of transmit and receive coils (7, 8, 9) is used for each instance of the sequence. The spatial sensitivity profiles are then computed in the positions of the pixels or voxels of the MR images formed from the acquired MR signals by taking the logarithm of the pixel or voxel values and by solving a linear system of equations for each pixel or voxel.
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Fuderer Miha
Kleihorst Robert Paul
Fetzner Tiffany A.
Koninklijke Philips Electronics , N.V.
Shrivastav Brij
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