Patent application number | Description | Published |
20100264926 | SYSTEM AND METHOD FOR PHASE RELAXED RF PULSE DESIGN - Techniques for designing RF pulses may be configured to produce improved magnitude profiles of the resulting magnetization by relaxing the phase constraint and optimizing the phase profiles. In one embodiment, a spinor-based, optimal control, optimal phase technique may be used to design arbitrary-tip-angle (e.g., large and small tip angle) RF pulses (both parallel transmission and single channel). In another embodiment, small tip angle RF pulses (both parallel transmission and single channel) may be designed using a small-tip-angle (STA) pulse design without phase constraint that is formulated as a parameter optimization problem. | 10-21-2010 |
20110241672 | APPARATUS AND METHOD FOR PARALLEL TRANSMISSION OF RF PULSES IN A SPIN ECHO SEQUENCE - A method, system, and apparatus including a magnetic resonance imaging (MRI) apparatus that includes an MRI system having a plurality of gradient coils, a radio-frequency (RF) transceiver system, an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly, and a computer. The computer is programmed to implement a spin echo sequence to acquire magnetic resonance (MR) data, where the spin echo sequence includes an excitation RF pulse and at least one refocusing pulse per repetition time (TR) of the excitation pulse. The computer is also programmed to transmit at least two component RF pulses in parallel channels during implementation of the spin echo sequence to produce a first refocusing RF pulse and programmed to reconstruct an image from spin echo sequence image data. | 10-06-2011 |
20120008842 | SYSTEM AND METHOD OF IMAGE ARTIFACT REDUCTION USING SELF-NAVIGATED REAL-TIME PHASE CORRECTION IN ECHO PLANAR IMAGING - An apparatus and method include a computer programmed to implement a scan sequence configured to elicit scan data, wherein the scan sequence comprises an echo planar imaging (EPI) sequence configured to elicit the image data and to acquire the scan data. The computer is also programmed to manipulate the scan data to determine a first plurality of phase errors in the image data responsible for a Nyquist ghost, wherein the manipulated scan data is free of navigator echo data, remove the first plurality of phase errors from the image data, and reconstruct an image based on the image data having the first plurality of phase errors removed therefrom. | 01-12-2012 |
20120146638 | SYSTEM AND METHOD FOR REDUCING LOCALIZED SIGNAL FLUCTUATION - A system and method is disclosed for eliminating localized fluctuation artifacts caused by fat signal contamination in MR images, the system includes a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images, and a computer programmed to apply a spectral-spatial fat saturation pulse, apply a slice selection gradient pulse, acquire imaging data of an imaging slice of interest, and generate an image. | 06-14-2012 |
20120169338 | System And Method For Generating A Magnetic Resonance Image Using Compressed Sensing And Parallel Imaging - A method for generating a magnetic resonance image includes acquiring a first k-space data set from each of a plurality of RF coils. The first k-space data set includes calibration data and randomly undersampled data. For each RF coil, a fully randomly sampled k-space data set is generated by removing a portion of the calibration data. A compressed sensing reconstruction technique is applied to the fully randomly sampled k-space data set to generate an aliased image, which is used to generate a uniformly undersampled k-space data set. A second k-space data set is generated by inserting the portion of the calibration data and a parallel imaging reconstruction technique is applied to the second k-space data set to synthesize unacquired data. The second k-space data set and the synthesized data are combined to generate a complete k-space data set for the RF coil. | 07-05-2012 |
20120271583 | SYSTEM AND METHOD FOR RETROSPECTIVE CORRECTION OF HIGH ORDER EDDY-CURRENT-INDUCED DISTORTION IN DIFFUSION-WEIGHTED ECHO PLANAR IMAGING - A computer is programmed to acquire calibration data from a calibration scan, the calibration data configured to characterize high order eddy current (HOEC) generated magnetic field error of an imaging system. The computer is also programmed to process the calibration data to generate a plurality of basis coefficients and a plurality of time constants and to calculate a plurality of basis correction coefficients based on the plurality of basis coefficients, the plurality of time constants, and gradient waveforms in a given pulse sequence. The computer is further programmed to execute a diffusion-weighted imaging scan that comprises application of a DW-EPI pulse sequence to acquire MR data from an imaging subject and reconstruction of an image based on the acquired MR data. The computer is also programmed to apply HOEC-generated magnetic field error correction during image reconstruction configured to reduce HOEC-induced distortion in the reconstructed image. | 10-25-2012 |
20120271584 | SYSTEM AND METHOD FOR PROSPECTIVE CORRECTION OF HIGH ORDER EDDY-CURRENT-INDUCED DISTORTION IN DIFFUSION-WEIGHTED ECHO PLANAR IMAGING - A computer is programmed to acquire calibration data from a calibration scan, the calibration data configured to characterize high order eddy current (HOEC) generated magnetic field error of an imaging system. The computer is also programmed to process the calibration data to generate a plurality of basis coefficients and a plurality of time constants and to calculate a plurality of basis correction coefficients based on the plurality of basis coefficients, the plurality of time constants, and gradient waveforms in a given pulse sequence. The computer is further programmed to execute a diffusion-weighted imaging scan that comprises application of a DW-EPI pulse sequence to acquire MR data from an imaging subject and reconstruction of an image based on the acquired MR data. The computer is also programmed to apply HOEC-generated magnetic field error correction during application of the DW-EPI pulse sequence configured to reduce HOEC-induced distortion in the reconstructed image. | 10-25-2012 |
20130265045 | SYSTEM AND METHOD FOR MULTISTATION IMAGE PASTING FOR WHOLE BODY DIFFUSION-WEIGHTED IMAGING - An MRI system includes a plurality of gradient coils positioned about a bore of a magnet, an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images, and a computer programmed to execute a diffusion-weighted imaging pulse sequence to acquire MR data from a subject over two or more stations, acquire imaging data of the subject over the two or more stations, reconstruct images that correspond to each of the two or more stations, and calculate an average intensity signal per slice within each of the reconstructed images. The computer is further programmed to adjust intensity within at least one of the reconstructed images based on the calculated average intensity signal within each of the reconstructed images and form a pasted image using a reconstructed image having its intensity adjusted and another reconstructed image. | 10-10-2013 |