Abstract: A system and method of MR imaging enables PROPELLER imaging to be feasibly carried out independently of slice orientation or anatomy of interest. The invention is directed to accelerated acquisition of blades of MR data that are rotated about a central region of k-space and reconstructing an image of arbitrary slice orientation from the blades of MR data that preserves contrast and reduces acceleration artifacts caused by signal amplitude variances.

Abstract: A system and method of MR imaging enables PROPELLER imaging to be feasibly carried out independently of slice orientation or anatomy of interest. The invention is directed to accelerated acquisition of blades of MR data that are rotated about a central region of k-space and reconstructing an image of arbitrary slice orientation from the blades of MR data that preserves contrast and reduces acceleration artifacts caused by signal amplitude variances.

Abstract: The present invention is directed to a method of MR imaging whereby a k-space blade extending through a center of k-space from a subject in motion is acquired. A high-pass convolution of the k-space blade with a reference k-space blade is then determined and converted to a ? function. In-plane motion of the subject during data acquisition of the k-space is then determined from the ? function.

Abstract: The present invention is directed to a method of MR imaging whereby a k-space blade extending through a center of k-space from a subject in motion is acquired. A high-pass convolution of the k-space blade with a reference k-space blade is then determined and converted to a ? function. In-plane motion of the subject during data acquisition of the k-space is then determined from the ? function.

Abstract: A method and system of MR imaging is disclosed that enables PROPELLER imaging to be feasibly carried out independently of slice orientation or anatomy of interest. The invention is directed to the acquisition of blades of MR data that are rotated about a central region of k-space and reconstructing an image of arbitrary slice orientation from the blades of MR data that is substantially absent of radial ripple artifacts caused by phase aliasing from tissue outside the field of view in the slice plane.

Abstract: A method of synchronizing initiation of a magnetic resonance image (MRI) acquisition to the arrival of a contrast agent in a structure of interest, such as an artery, includes repeatedly performing a first MRI scan until the first MRI scan indicates that the contrast agent has arrived. The first MRI scan acquires a three-dimensional MRI data set from the structure of interest. Preferably, the first MRI scan is a partial MRI scan that produces a low resolution image. Once the first MRI scan indicates that the contrast agent has arrived in the structure of interest, a second MRI scan is performed that acquires a second three-dimensional MRI data set from the structure of interest. The second MRI scan is preferably a full MRI scan that produces a full fidelity image. The manner of data acquisition is advantageously the same for both the first MRI scan and the second MRI scan.

Abstract: The present invention provides a system and method of increasing the sampling rate for MR data acquisition. By implementing ensemble sampling techniques, the present invention provides higher data sampling rates that are useful for several MR data acquisition applications including Echo Planar Imaging, Functional Magnetic Resonance Imaging, and Sensitivity Encoding Imaging (SENSE) techniques. By multiplying an MR signal by a series of pure sinusoids having the same frequency but shifted by an incremental phase, the MR signal may be separated into a number of channels which can be sampled at lower rates by analog-to-digital converters. The output from the converters may then be reconstructed using one of a number of interpolation techniques to create a single digital channel with increased bandwidth. The single channel with increased bandwidth may then be used to acquire MR data with an improved sampling rate.

Abstract: The present invention provides a system and method of increasing the sampling rate for MR data acquisition overcoming the aforementioned drawbacks. By implementing ensemble sampling techniques, the present invention provides higher data sampling rates that are useful for several MR data acquisition applications including Echo Planar Imaging, Functional Magnetic Resonance Imaging, and Sensitivity Encoding Imaging (SENSE) techniques. By multiplying an MR signal by a series of pure sinusoids having the same frequency but shifted by an incremental phase, the MR signal may be separated into a number of channels which can be sampled at lower rates by analog-to-digital converters. The output from the converters may then be reconstructed using one of a number of interpolation techniques to create a single digital channel with increased bandwidth. The single channel with increased bandwidth may then be used to acquire MR data with an improved sampling rate.

Abstract: An MRI system performs a real-time scan in which image frames are produced as the image is moved to different locations in the patient. The location at which each set of image data is acquired is compared, and image data acquired at the same location are combined to improve image quality. An autonex feature enables averaging of successive image data acquisitions and a frame rate feature enables combining of partial NEX acquisitions.

Abstract: In an MRI system NMR data is acquired and an image is reconstructed based on the net phase or phase difference of spins at locations in the imaged object. The phase or phase difference image is corrected for errors caused by non-linearities in one or more of the gradient fields. The phase or phase difference image values are weighted with spin signal magnitude image values and their locations warped to reflect gradient field non-linearity. The warped values are remapped to the image pixel locations and converted back to phase values by dividing by an average spin signal magnitude. In this manner geometric distortion caused by non-uniform magnetic field gradients are corrected without loss of quantitative phase or phase difference information.