Abstract: Apparatus, methods, and other embodiments associated with multi-slice blipped TrueFISP-CAIPIRINHA in magnetic resonance imaging (MRI) are described. One example apparatus produces CAIPIRINHA phase cycling in a TrueFISP-CAIPRINHA pulse sequence using a blipped gradient pattern rather than using radio frequency (RF) pulses. The phase cycling is produced by controlling a gradient coil in an MRI apparatus to produce a pre-scan pulse that is configured to set magnetization into a steady state position and then controlling the gradient coil to produce a balanced alternating phase pulse per repetition (TR). The balanced alternating phase pulse is configured to introduce a CAIPIRINHA aliasing pattern between slices. Controlling the gradient coil includes selectively adding and removing a finite gradient area from de-phase pulses and re-phase pulses in the pulse sequence.

Abstract: Apparatus, methods, and other embodiments associated with magnetic resonance imaging (MRI) blipped trajectories having varying blip amplitudes are described. One example method includes controlling an MRI apparatus to produce a set of blipped trajectories including a first blipped trajectory having a first blip amplitude and a second, different blipped trajectory having a second, different blip amplitude. The blip amplitudes may be based on a relationship between a trajectory and a reference. The relationship may be, for example, a rotation angle. The rotation angle may be a proxy for information including a gradient trajectory speed associated with a blipped trajectory or an amount of unused gradient energy available while producing the blipped trajectory. The blip amplitudes may be selected to produce incoherent sampling during an MRI acquisition that uses the blipped trajectories. In one example, readout directions may be altered between trajectories to reduce regularity in k-space.

Abstract: A new and improved method for tracking and/or spatial localization of an invasive device in Magnetic Resonance Imaging (MRI) is provided. The invention includes providing an invasive device including a marker having a chemically shifted signal source with a resonant frequency different from the chemical species of the subject to be imaged, applying a pulse sequence, detecting the resulting RF magnetic resonance signals, and determining the 3D coordinates of the marker. The invention also includes generating scan planes and reconstructing an image from the detected signals to generate an image having the marker contrasted from the subject. The invasive device includes a marker having a chemically shifted signal source which has a resonant frequency different from the chemical species of the subject to be imaged for use in tracking the device during imaging.

Abstract: Apparatus, methods, and other embodiments associated with multi-slice blipped TrueFISP-CAIPIRINHA in magnetic resonance imaging (MRI) are described. One example apparatus produces CAIPIRINHA phase cycling in a TrueFISP-CAIPRINHA pulse sequence using a blipped gradient pattern rather than using radio frequency (RE) pulses. The phase cycling is produced by controlling a gradient coil in an MRI apparatus to produce a pre-scan pulse that is configured to set magnetization into a steady state position and then controlling the gradient coil to produce a balanced alternating phase pulse per repetition (TR). The balanced alternating phase pulse is configured to introduce a CAIPIRINHA aliasing pattern between slices. Controlling the gradient coil includes selectively adding and removing a finite gradient area, from de-phase pulses and re-phase pulses in the pulse sequence.

Abstract: Apparatus, methods, and other embodiments associated with magnetic resonance imaging (MRI) blipped trajectories having varying blip amplitudes are described. One example method includes controlling an MRI apparatus to produce a set of blipped trajectories including a first blipped trajectory having a first blip amplitude and a second, different blipped trajectory having a second, different blip amplitude. The blip amplitudes may be based on a relationship between a trajectory and a reference. The relationship may be, for example, a rotation angle. The rotation angle may be a proxy for information including a gradient trajectory speed associated with a blipped trajectory or an amount of unused gradient energy available while producing the blipped trajectory. The blip amplitudes may be selected to produce incoherent sampling during an MRI acquisition that uses the blipped trajectories. In one example, readout directions may be altered between trajectories to reduce regularity in k-space.

Abstract: Example systems and methods control a parallel magnetic resonance imaging (pMRI) apparatus to acquire non-Cartesian (e.g., spiral) calibration data sets throughout time. Example systems and methods also control the pMRI apparatus to acquire an under-sampled non-Cartesian data set from the object to be imaged. Example systems and methods then control the pMRI apparatus to reconstruct an image of the object to be imaged from the under-sampled non-Cartesian data set. The reconstruction depends, at least in part, on a through-time non-Cartesian GRAPPA calibration where a value for a point missing from k-space in the under-sampled non-Cartesian data set is computed using a GRAPPA weight set calibrated and applied for the missing point. The GRAPPA weight set is computed from data in the non-Cartesian calibration data sets.

Abstract: Example systems and methods control a parallel magnetic resonance imaging (pMRI) apparatus to acquire radial calibration data sets throughout time. Example systems and methods also control the pMRI apparatus to acquire an under-sampled radial data set from the object to be imaged. Example systems and methods then control the pMRI apparatus to reconstruct an image of the object to be imaged from the under-sampled radial data set. The reconstruction depends, at least in part, on a through-time radial GRAPPA calibration where a value for a point missing from k-space in the under-sampled radial data set is computed using a GRAPPA weight set calibrated and applied for the missing point. The GRAPPA weight set is computed from data in the radial calibration data sets.

Abstract: Example systems and methods control a parallel magnetic resonance imaging (pMRI) apparatus to acquire non-Cartesian (e.g., spiral) calibration data sets throughout time. Example systems and methods also control the pMRI apparatus to acquire an under-sampled non-Cartesian data set from the object to be imaged. Example systems and methods then control the pMRI apparatus to reconstruct an image of the object to be imaged from the under-sampled non-Cartesian data set. The reconstruction depends, at least in part, on a through-time non-Cartesian GRAPPA calibration where a value for a point missing from k-space in the under-sampled non-Cartesian data set is computed using a GRAPPA weight set calibrated and applied for the missing point. The GRAPPA weight set is computed from data in the non-Cartesian calibration data sets.

Abstract: A system and method to perform parallel MR imaging are disclosed. The system comprises an MR imaging machine and a probe having at least two MR RF reception coils. Each coil of the probe is operationally connected to a separate receiver channel of the MR imaging machine. The MR imaging machine implements a partially parallel acquisition method to excite precessing nuclear spins, in and around an internal segment of a patient into which the probe is inserted, and to use the coils of the catheter to simultaneously sample a plurality of response signals to form reduced k-space data sets for each of the coils. The plurality of response signals represent nuclear magnetic resonance signals arising from the precessing nuclear spins. The reduced k-space data sets are further processed by the MR imaging machine to generate a full volume dataset of a region in and around the vessel.

Abstract: The invention relates to micelles that are elaborated with functionality useful for imaging and/or selectively targeting tissue, e.g., in the delivery of hydrophobic agents.

Abstract: A system and method to perform parallel MR imaging are disclosed. The system comprises an MR imaging machine and a probe having at least two MR RF reception coils. Each coil of the probe is operationally connected to a separate receiver channel of the MR imaging machine. The MR imaging machine implements a partially parallel acquisition method to excite precessing nuclear spins, in and around an internal segment of a patient into which the probe is inserted, and to use the coils of the catheter to simultaneously sample a plurality of response signals to form reduced k-space data sets for each of the coils. The plurality of response signals represent nuclear magnetic resonance signals arising from the precessing nuclear spins. The reduced k-space data sets are further processed by the MR imaging machine to generate a full volume dataset of a region in and around the vessel.

Abstract: Systems, methodologies, media, and other embodiments associated with improving MRI scan times and mitigating the effects of aliasing artifacts when the Nyquist data sampling threshold is not satisfied are described. One exemplary method embodiment includes producing an oscillating phase encoding gradient during a readout phase, where the gradient facilitates acquiring data from multiple phase encoding lines during a single readout phase. The exemplary method embodiment may also include reconstructing an image from the data acquired from two or more phase encoding lines.

Abstract: Systems, methodologies, media, and other embodiments associated with a block-by-block off-resonance frequency estimation method are described. One exemplary method embodiment includes calculating a field map from local B0 off resonance frequency estimates. The example method may also include performing water-fat decomposition and signal de-blurring based on the calculated map.

Abstract: Systems, methodologies, media, and other embodiments associated with facilitating intra-procedurally determining the position of an internal anatomical target location using an externally measurable parameter are described. One exemplary method embodiment includes pre-procedurally correlating internal anatomy motion with external marker motion. The example method may also include providing computer graphics to an augmented reality system during a percutaneous procedure to facilitate image guiding an interventional device with respect to the internal anatomy.

Abstract: Systems, methodologies, media, and other embodiments associated with automatically adapting MRI controlling parameters are described. One exemplary method embodiment includes configuring an MRI apparatus to acquire MR signal data using a non-rectilinear trajectory. The example method may also include acquiring MR signals, transforming the MR signals into image data, and selectively adapting the MRI controlling parameters based, at least in part, on information associated with the MR signals.

Abstract: A method and system for improving image quality by correcting errors introduced by rotational motion of an object being imaged is provided. The object is associated with a fiducial mark. The method provides a computer executable methodology for detecting a rotation and selectively reordering, deleting and/or reacquiring projection data.

Abstract: Extended-coverage magnetic resonance imaging coils with optimized homogeneity in longitudinal sensitivity are described. One exemplary coil includes four elements, where two of the elements are opposed-solenoid imaging elements and two of the elements are single loop imaging elements.

Abstract: Methods are described for efficient reconstruction of MRI data. In one practice, new reconstruction algorithms for non-uniformly sampled k-space data are presented. In the disclosed algorithms, Iterative Next-Neighbor re-Gridding (INNG) and Block INNG (BINNG), iterative procedures are performed using larger rescaled matrices than the target grid matrix In BINNG algorithm, the sampled k-space region is partitioned into several blocks and the INNG algorithm is applied to each block. In another practice, a novel partial spiral reconstruction (PFSR) uses an estimated phase map from a low-resolution image reconstructed from the central k-space data and performs iterations, similar to the iterative procedures with INNG, with an imposed phase constraint. According to yet another practice, an off-resonance correction is performed on matrices that are smaller than the full image matrix. All these methods reduce the computational costs while rendering high-quality reconstructed images.

Abstract: SENSitivity Encoding (SENSE) has demonstrated potential for significant scan time reduction using multiple receiver channels. SENSE reconstruction algorithms for non-uniformly sampled data proposed to date require relatively high computational demands. A Projection Onto Convex Sets (POCS)-based SENSE reconstruction method (POCSENSE) has been recently proposed as an efficient reconstruction technique in rectilinear sampling schemes. POCSENSE is an iterative algorithm with a few constraints imposed on the acquired data sets at each iteration. Although POCSENSE can be readily performed on rectilinearly acquired k-space data, it is difficult to apply to non-uniformly acquired k-space data. Iterative Next Neighbor re-Gridding (INNG) algorithm is a recently proposed new reconstruction method for non-uniformly sampled k-space data. The POCSENSE algorithm can be extended to non-rectilinear sampling schemes by using the INNG algorithm.

Abstract: A magnetic resonance data acquisition method includes designating a plurality of parameters that are representative of conditions for acquiring data from a magnetic resonance apparatus, at least one of the parameters being variable; designating at least one objective function measuring the quality of the acquired magnetic resonance data; optimizing the at least one objective function using an optimization algorithm to find at least one set of optimum values for the parameters characterizing data acquisition; configuring the magnetic resonance apparatus with the parameters determined above, configuring by one set of the optimum values of the parameters, and instructing a magnetic resonance imaging apparatus to apply the field to the target of the data acquisition to acquire the data.