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US 6,289,232 B1Granted
Coil array autocalibration MR imaging
AssigneeBeth Israel Deaconess Medical Center, Inc.
InventorsPeter M. Jakob, Daniel K. Sodickson, Mark Griswold
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AssigneeBeth Israel Deaconess Medical Center, Inc.
InventorsPeter M. Jakob, Daniel K. Sodickson, Mark Griswold
Estimating the term…
A magnetic resonance (MR) imaging apparatus and technique exploits spatial information inherent in a surface coil array to increase MR image acquisition speed, resolution and/or field of view. Magnetic resonance response signals are acquired simultaneously in the component coils of the array and, using an autocalibration procedure, are formed into two or more signals to fill a corresponding number of lines in the signal measurement data matrix. In a Fourier embodiment, lines of the k-space matrix required for image production are formed using a set of separate, preferably linear combinations of the component coil signals to substitute for spatial modulations normally produced by phase encoding gradients. One or a few additional gradients are applied to acquire autocalibration (ACS) signals extending elsewhere in the data space, and the measured signals are fitted to the ACS signals to develop weights or coefficients for filling additional lines of the matrix from each measurement set. The ACS lines may be taken offset from or in a different orientation than the measured signals, for example, between or across the measured lines. Furthermore, they may be acquired at different positions in k-space, may be performed at times before, during or after the principal imaging sequence, and may be selectively acquired to optimized the fitting for a particular tissue region or feature size. The in vivo fitting procedure is readily automated or implemented in hardware, and produces an enhancement of image speed and/or quality even in highly heterogeneous tissue. A dedicated coil assembly automatically performs the calibration procedure and applies it to measured lines to produce multiple correctly spaced output signals. One application of the internal calibration technique to a subencoding imaging process applies the ACS in the central region of a sparse set of measured signals to quickly form a full FOV low resolution image. The full FOV image is then used to determine coil sensitivity related information and dealias folded images produced from the sparse set.
A method of magnetic resonance imaging of a continuous region of a body by conditioning nuclear spins and measuring RF signals indicative of the conditioned spins, by performing multiple steps of spatially conditioning spins in the region and collecting MR response signals from the region in plural receiving coils, and performing a spatial transformation of an ordered data set to produce a magnetic resonance image of said region, wherein the method includes the steps of
Apparatus for magnetic resonance imaging of a region of a body and including first means for conditioning nuclear spins and measuring RF signals indicative of the conditioned spins, control means for controlling the first means to perform multiple steps of spatially conditioning spins in the region and collecting MR response signals from the region in plural receiving coils, and image forming means for performing a spatial transformation of an ordered data set to produce a magnetic resonance image of said region, wherein the control means controls the first means to
A dedicated coil assembly for MR imaging comprising plural MR signal receiving coils arranged to receive MR responses from a region and produce signals indicative thereof, and a microprocessor operative on an autocalibration signal received in said coils to determine a transformation, said microprocessor applying said transformation of an MR response acquired by said plural signal receiving coils to provide a signal output comprising multiple independent signal lines and thereby more quickly fill a signal data matrix.
A method of magnetic resonance imaging a region of a body by conditioning nuclear spins and measuring magnetic response signals indicative of the conditioned spins, wherein the method includes performing multiple steps of spin conditioning and of collecting measurement signal responses from the region in plural receiving coils, establishing an ordered data set of collected measurement response signals, and performing a spatial transformation of the ordered data set to produce a MR image of said region, wherein the method includes the steps of
Apparatus for magnetic resonance imaging a region of a body by conditioning nuclear spins and measuring magnetic response signals indicative of the conditioned spins, wherein the apparatus includes first means for performing multiple steps of spin conditioning and of collecting measurement signal responses from the region in plural receiving coils, signal processing means for establishing an ordered data set of collected measurement response signals, and image forming means for transforming the ordered data set to produce a MR image of said region,
Dependencies are inferred from the claim text.