Abstract: Methods and apparatus for fabricating a magnetic resonance imaging (MRI) gradient coil for generating magnetic field gradients are provided. The method includes determining a pattern of gradient current paths on a surface using a set of stream functions oriented in at least one of a z-gradient, a y-gradient; and an x-gradient, and arranging conductive material to define a current path that conforms to the determined gradient current paths.

Abstract: A method of and system for parallel imaging using a Magnetic Resonance Imaging (MRI) system is provided. The method comprises acquiring a plurality of magnetic resonance (MR) signals from a receiver coil array placed about a subject in the MRI system, where the receiver coil array has a plurality of receiver elements arranged in rows and, during application of a readout gradient in a frequency encoding direction, shifting receiver frequencies by a selectable amount for each row of the array in order to shift a limited field of view (FOV) in the frequency encoding direction.

Abstract: A method for producing an image of a selected region of interest included in a volume within a moving and deforming object in a Magnetic Resonance Imaging (MRI) system includes applying at least one integrated preparatory pulse sequence to the region of interest prior to any subsequent imaging sequences. The integrated preparatory pulse sequence is adapted to simultaneously, alter longitudinal magnetization of spins located outside of the selected region and to further impose a grid pattern on the selected region. The integrated preparatory pulse sequence is subsequently followed by a projection imaging technique.

Abstract: A parallel Magnetic Resonance Imaging (MRI) system is provided for reconstructing images, to enable accelerated MRI with minimal artifacts. The MRI system comprises an array of magnetic resonance (MR) coils arranged in an array for detecting a plurality of MR signals, each coil having a corresponding spatial sensitivity profile and a processing means for processing the plurality of MR signals with at least one filter bank to reconstruct at least one image.

Abstract: A method and system are provided for acquiring images using a magnetic resonance imaging (MRI) system. The method comprises the step of applying a plurality of steady-state free precession (SSFP) radio-frequency (RF) excitation pulses in a selected pattern of varying amplitudes and phases such that signals corresponding to the pattern of pulses are substantially immune to magnetic field inhomogeneity of the MRI system. The pulses have substantially equal spacing between all neighboring pulses and between successive groups of pulses. The method further comprises the step of reading a plurality of signals corresponding to the pulses.

Abstract: A method and system are provided for acquiring images with water and lipid separation using a magnetic resonance imaging (MRI) system comprising applying a plurality of steady-state free precession (SSFP) radio-frequency (RF) excitation pulses to discriminate lipids from water, the pulses having respective inter-pulse gaps between the pulses, the inter-pulse gaps varying among different widths.

Abstract: A method and system are provided for acquiring images with water and lipid separation using a magnetic resonance imaging (MRI) system comprising applying a plurality of steady-state free precession (SSFP) radio-frequency (RF) excitation pulses having respective amplitudes that correspond substantially to a binomial distribution to discriminate lipids from water.

Abstract: A method for acquiring image data from a subject during a scan with a Magnetic Resonance Imaging (MRI) system comprising the steps of acquiring a reference data set of a region of interest, acquiring a plurality of free-breathing data sets, and, selectively processing the plurality of free-breathing data sets in comparison with the reference data set to be used in creating an image of the region of interest. The reference data set comprises breath-held data set or, alternatively, free-breathing data.

Abstract: An MRI system acquires image data using a spiral pulse sequence in which k-space is sampled in a trajectory comprised of a spiral segment and a symmetric spiral tail segment. The spiral segments partially sample throughout the extent of k-space and the symmetric spiral tail segment samples only in a central region of k-space. The central region of k-space is fully sampled and a phase correction method is used to reconstruct an image from the under-sampled peripheral k-space data set.

Abstract: An MRI system performs a cardiac gated scan of a moving coronary artery using preparatory pulse sequences and two-dimensional EPI (echo planar imaging) pulse sequences. The preparatory pulse sequence saturates spin magnetization in regions surrounding a slice which contains the coronary artery at one point in time during each cardiac cycle. The EPI imaging pulse sequence is performed later in the cardiac cycle after the coronary artery has moved and a two-dimensional image is reconstructed by projecting NMR signals from a volume within which the coronary artery moves during the cardiac cycle.

Abstract: A scan control device located in the bore of an MRI system magnet includes tracking coils and a display. Location and alignment of the scan control device is tracked by the MRI system using signals acquired from the tracking coils. These signals are also used to update the scan parameters such that the scan plane of the image acquired by the MRI system is controlled by the scan control device location and orientation. The image is produced on the display to provide an attending physician with interactive control of the image from the magnet bore.

Abstract: An imaging method and system generates images of non-planar portions of a three dimensional data point array wherein the non-planar portion corresponds to a non-planar object. The method includes selecting at least two different intermediate imaging planes, each selected plane including at least a portion of the object to be imaged, generating cross-sectional views perpendicular to each intermediate plane, selecting a viewing plane, projecting the cross-sectional views onto the viewing plane to generate transition value sets, and combining the transition value sets to generate values for each pixel in a display.

Abstract: An MRI system produces a series of image frames of a blood vessel using a cardiac gated, M-mode Fourier-velocity-encoding pulse sequence. The pulse-wave velocity of a velocity wave traversing the field of view of the image frames is determined by cross correlating a selected reference image frame with the other image frames to locate the relative position of the velocity wave in each of those other image frames, and calculating the propagation velocity of the velocity wave from its relative positions in those other image frames.

Abstract: A reference image R is selected and a region of interest (ROI) is interactively selected encompassing a desired structure from a sequence of images of a moving structure. This ROI is cross-correlated with other real-time images by multiplication in the Fourier frequency domain, to determine if the desired structure is present in the image. If the structure is present, this image may be averaged with other images in which the structure is present to produce higher resolution adaptively averaged images. This invention is particularly useful in imaging coronary vessels. In an alternative embodiment, the offset of the desired structure may be calculated in a series of images. The images may then be sorted by this offset, and played back in that order to provide a "movie-like" display of the desired structure moving with the periodic motion.

Abstract: A magnetic resonance (MR) imaging method uses chemical shift and/or slice selective inversion pulse to create angiograms of coronary arteries. In one embodiment blood is doped with a contrast enhancement agent and a sequence of slice selective and chemical shift selective inversion pulses are applied. Detection RF pulses then generate an image signal. In another embodiment two sequential chemical shift inversion pulses are applied followed by detection RF pulses for imaging.

Abstract: NMR images indicative of thermal changes in tissues undergoing therapy are produced using a gradient-recalled double-echo pulse sequence. A reference phase image is produced using a short echo time (TE.sub.1) and a measurement phase image is produced with a longer echo time (TE.sub.2). Temperature maps are produced during therapy using the phase difference information at corresponding pixels of the two phase images.