Abstract: Water-fat separated magnetic resonance (MR) images with balanced steady-state free precession (SSFP) are produced. The acquired SSFP signals are isolated into multiple echo components in which the phase arrangements between the water and fat signals are controlled by appropriately selecting the TR and TE values of the SSFP imaging sequence. From the isolated echo components, the effects of the field inhomogeneities are corrected and water and fat images are separated.

Abstract: A method and a system for acquiring diffusion magnetic resonance images with compensation of the effects of eddy currents induced by the diffusion weighting (DW) gradient pulses. Prescan data are first acquired using the same DW sequence to be used for imaging. The prescan data are used to obtain eddy current parameters that model the effects of DW-induced eddy currents under the exact conditions under which DW images are to be acquired. The DW imaging sequence is then slightly modified according to the eddy current parameters and used to acquire DW image data with the effects of DW-induced eddy currents compensated.

Abstract: A method and a system for acquiring diffusion magnetic resonance images with compensation of the effects of eddy currents induced by the diffusion weighting (DW) gradient pulses. Prescan data are first acquired using the same DW sequence to be used for imaging. The prescan data are used to obtain eddy current parameters that model the effects of DW-induced eddy currents under the exact conditions under which DW images are to be acquired. The DW imaging sequence is then slightly modified according to the eddy current parameters and used to acquire DW image data with the effects of DW-induced eddy currents compensated.

Abstract: A method to separate two chemically-shifted components of water (w) and fat (f) signals by: (i) estimating the field inhomogeneity ? through a treatment of the residuals of the Moore-Penrose solution of the following equations: cos(?n?)*w+cos [?n(1+?)]*f=real (In) and sin(?n?)*w+sin [?n(1+?)]*f=imaginary (In), and (ii) using the estimated ? to determine the resulting solution for w and f from the original input signals In.

Abstract: A system has been developed for mapping the magnetic field during a balanced steady-state free precession (SSFP) sequence. Field maps are generated by analyzing the magnitude of images acquired using the SSFP imaging sequences with phase increment or frequency shift. The system maps the magnetic field relevant to the imaging sequence and need not rely on phase information. The field maps may be applied to adjust the hardware for correcting the field anomalies contained in the maps. The field maps may also be used for separation of water and fat signals in SSFP imaging.

Abstract: A system has been developed for mapping the magnetic field during a balanced steady-state free precession (SSFP) sequence. Field maps are generated by analyzing the magnitude of images acquired using the SSFP imaging sequences with phase increment or frequency shift. The system maps the magnetic field relevant to the imaging sequence and need not rely on phase information. The field maps may be applied to adjust the hardware for correcting the field anomalies contained in the maps. The field maps may also be used for separation of water and fat signals in SSFP imaging.

Abstract: A method is disclosed for determining a gradient-induced cross-term magnetic field in a magnetic resonance imaging (MRI) system comprising: positioning an object in a static magnetic field; applying a radio frequency (RF) saturation pulse that spatially saturates nuclei of a slice of the object and applying an echo planar imaging (EPI) sequence to form an image of a slice of the object; generating a cross-field correction factor by analyzing the spatial distribution of the saturation line in the image.

Abstract: An improved magnetic resonance imaging (MRI) methodology uses an abbreviated initial MRI sequence to generate sequence diagnostic parameters. The sequence diagnostic parameters have a fixed relationship to certain sequence-conditioning parameters, and are used for calculating characteristic values of the sequence-conditioning parameters. The read out gradient pulse sequence is modified in accordance with the calculated characteristic values of the sequence-conditioning parameters. The modified read out gradient pulse sequence is then incorporated into a subsequent MRI pulse sequence used for obtaining a diagnostic image. The methodology has particular application in so called ultra fast MRI process which include echo-planar imaging (EPI) and echo-volume imaging (EVI).

Abstract: A method to separate two chemically-shifted components of water (w) and fat (f) signals by: (i) estimating the field inhomogeneity ? through a treatment of the residuals of the Moore-Penrose solution of the following equations: cos(?n?)*w+cos [?n(1+?)]*f=real (In) and sin(?n?)*w+sin [?n(1+?)]*f=imaginary (In), and (ii) using the estimated ? to determine the resulting solution for w and f from the original input signals In.

Abstract: A method is disclosed for determining a gradient-induced cross-term magnetic field in a magnetic resonance imaging (MRI) system comprising: positioning an object in a static magnetic field; applying a radio frequency (RF) saturation pulse that spatially saturates nuclei of a slice of the object and applying an echo planar imaging (EPI) sequence to form an image of a slice of the object; generating a cross-field correction factor by analyzing the spatial distribution of the saturation line in the image.

Abstract: A method is disclosed for determining a gradient-induced cross-term magnetic field in a magnetic resonance imaging (MRI) system involving the steps of: positioning an object in a static magnetic field; applying a radio frequency (RF) excitation pulse that spatially selects a slice of the object; applying an incremented phase-encoding magnetic gradient field along a phase encoding gradient field direction parallel to the slice phase; applying a selective RF refocusing pulse to select a line in the slice; applying a switched readout magnetic gradient; which causes a cross-term magnetic field, generating a data array of a phase-encoding gradient and a corresponding sample data point along the selected line, and determining a center frequency distribution (CF) for the selected line, where the CFR is indicative of a gradient-induced cross-term magnetic field.

Abstract: An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null.

Abstract: An MRI imaging system provides an audible feedback signal in the gantry room triggered by a physiological sensor on the patient. The feedback signal is a sound generated by one of the MRI gradient coils. The sensor output signal may be indicative of the patient's heartbeat, or other physiological event. The application of the sequence causes the coil to emit a sound that is associated with the sensor output signal.

Abstract: An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null.

Abstract: An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null.

Abstract: The invention is an MRI imaging system that seamlessly switches between a fast imaging fluoro-mode and a diagnostic imaging mode. The fluoro-mode is used to quickly obtain an image which provides confirmation that the selection of MR imaging parameters are proper and to provide an opportunity to adjust these selections. After the selections have been confirmed and adjusted, the system is switched to a normal diagnostic image mode using the parameter selects as modified during fluoro-mode imaging.

Abstract: An MRI imaging system provides an audible feedback signal in the gantry room triggered by a physiological sensor on the patient. The feedback signal is a sound generated by one of the MRI gradient coils. The sensor output signal may be indicative of the patient's heartbeat, or other physiological event. The application of the sequence causes the coil to emit a sound that is associated with the sensor output signal.

Abstract: An MRI imaging system provides an audible feedback signal in the gantry room triggered by a physiological sensor on the patient. The feedback signal is a sound generated by one of the MRI gradient coils. The sensor output signal may be indicative of the patient's heartbeat, or other physiological event. The application of the sequence causes the coil to emit a sound that is associated with the sensor output signal.

Abstract: A magnetic resonance imaging (MRI) method is disclosed for generating and identifying water and fat separated MR images. Image data is first acquired to obtain two echo images with the water and fat signals orthogonal in the first echo image, and parallel/anti-parallel in the second echo image. The effect of background field inhomogeneties are removed, and water and fat images are separated from each other. The separated water and fat images are identified according to the difference of their precessing frequencies.

Abstract: An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null.