Patent classifications
G01R33/56366
System and method for tracking cerebral blood flow in fMRI
A system and method for analyzing blood flow in a subject's brain is provided. In some aspects, the method includes analyzing fMRI data to identify signals related to blood flow, and selecting a zero time lag seed regressor using the identified signals. The method also includes correlating the selected seed regressor to identify a subset of the fMRI data that correlates with the seed regressor and is offset in time, combining the subset of the data to determine a time-delayed regressor, and performing repetitions to obtain a number of time-delayed regressors, where for each repetition, the seed regressor is adjusted using a previous time-delayed regressor. The method further includes analyzing the data using the time-delayed regressors to determine blood delivery from vessels across the brain, and generating a report. In some aspects, a second recursive procedure may be performed using an optimized seed regressor obtained from a first recursive procedure.
Arterial spin labeling with reduced acoustic noise emissions and method of operation thereof
A magnetic resonance imaging (MRI) system (100, 600) that generates information indicative of a fluid flow in accordance with a pseudo-continuous arterial spin labeling (pCASL) method. The MRI system may include at least one controller (104, 610) configured to generate a pseudo-continuous arterial spin labeling (pCASL) pulse sequence (200) including at least a first gradient (GR) pulse sequence (207) having a sinusoidal waveform including a plurality of cycles, and a second radio frequency (RF) pulse sequence (205) including a half-wave rectified sinusoidal waveform having a plurality of cycles and which is synchronous with the first GR pulse sequence; label at least part of the fluid flow in a labeling region during a labeling mode using the pCASL pulse sequence; acquire label and control image information of the fluid flow at an imaging region proximal to downstream of the labeling region; and/or generate image information in accordance with a difference of the acquired label and control image information. The sinusoidal gradient waveform results in less acoustic noise during execution of the pulse sequence.
System and method for using coils in magnetic resonance imaging
Some implementations provide an MRI system that includes: a housing having a bore accommodating a portion of a subject; a main magnet enclosed by said housing and configured to generate a substantially uniform magnet field within the bore; a gradient sub-system to provide perturbations to the substantially uniform magnet field; a flexible coil assembly configured to (i) receive radio frequency (RF) signals from the subject in response to the portion of the subject being scanned, and (ii) generate and apply B.sub.0 shimming to improve a field homogeneity of the substantially uniform magnetic field; and a control unit configured to: drive the gradient sub-system using a gradient waveform; and receive measurement results responsive to the gradient waveform such that a coupling between the gradient sub-system and the flexible coil assembly is determined and subsequently reduced in response to the determined coupling exceeding a pre-determined threshold.
Methods and apparatus for scan time reductions in magnetic resonance imaging using outer volume supression
Methods for fast magnetic resonance imaging (MRI) using a combination of outer volume suppression (OVS) and accelerated imaging, which may include simultaneous multislice (SMS) imaging, data acquisitions amenable to compressed sensing reconstructions, or combinations thereof. The methods described here do not introduce fold-over artifacts that are otherwise common to reduced field-of-view (FOV) techniques.
METHOD AND SYSTEM FOR AUTOMATICALLY GENERATING AND ANALYZING FULLY QUANTITATIVE PIXEL-WISE MYOCARDIAL BLOOD FLOW AND MYOCARDIAL PERFUSION RESERVE MAPS TO DETECT ISCHEMIC HEART DISEASE USING CARDIAC PERFUSION MAGNETIC RESONANCE IMAGING
A computer-implemented method for automatically generating a fully quantitative myocardial blood flow map, comprising: receiving myocardial perfusion magnetic resonance imaging (MRI) images and arterial input function (AIF) MRI images; correcting a motion of a heart in the myocardial perfusion MRI images and the AIF MRI images, thereby obtaining motion corrected myocardial perfusion MRI images and motion corrected AIF images; correcting an intensity of the motion corrected myocardial perfusion MRI images and an intensity of the motion corrected AIF images, thereby obtaining surface coil intensity corrected MRI images and surface coil intensity corrected AIF images; using the surface coil intensity corrected MRI images and the surface coil intensity corrected AIF images, determining time-signal intensity characteristics and segmenting a left ventricle myocardial tissue region; and generating the myocardial blood flow map using the motion corrected myocardial perfusion MRI images, the left ventricle myocardial tissue region segmentation and the time-signal intensity characteristics.
SYSTEM, METHOD AND COMPUTER-ACCESSIBLE MEDIUM FOR FACILITATING NOISE REMOVAL IN MAGNETIC RESONANCE IMAGING
An exemplary system, method and computer-accessible medium for generating a denoised magnetic resonance (MR) image(s) of a portion(s) of a patient(s) can be provided, which can include, for example, generating a plurality of MR images of the portion(s), where a number of the MR images can be based on a number of MR coils in a MR apparatus used to generate the MR images, generating MR imaging information by denoising a first one of the MR images based on another one of the MR images, and generating the denoised MR image(s) based on the MR imaging information. The number of the MR coils can be a subset of a total number of the MR coils in the MR apparatus. The number of the MR coils can be a total number of the MR coils in the MR apparatus. The MR information can be generated by denoising each of the MR images based on the other one of the MR images.
TESTING FOR NEUROVASCULAR UNCOUPLING IN MULTIPLE SCLEROSIS USING SEQUENTIAL GAS DELIVERY VERSUS FIXED INSPIRED CO2
An apparatus and method for assessing vascular compliance in subjects with multiple sclerosis using sequential gas delivery is provided. The apparatus includes a gas delivery device and a processor. The processor controls the gas delivery device to deliver a first and second gas during a single inspiration. The first gas contains a mixture of oxygen and carbon dioxide necessary to target an end-tidal concentration of the two gases. The second gas includes a concentration of carbon dioxide equal to the target end-tidal concentration of carbon dioxide.
NON-METALLIC MAGNETIC RESONANCE CONTRAST AGENT
The present application provides a compound comprising at least one isotopically labeled nitrogen atom for use in diagnosing a condition or disease in a subject, compositions and kits comprising the compound and methods of using the same.
Method of fast imaging of NMR parameters with variably-accelerated sensitivity encoding
A method of spatially imaging a nuclear magnetic resonance (NMR)parameter whose measurement requires the acquisition of spatially localized NMR signals in a sample includes placing the sample in an MRI apparatus with a plurality of MRI detectors each having a spatial sensitivity map; and applying MRI sequences adjusted to be sensitive to the NMR parameter. At least one of the MRI sequences is adjusted so as to substantially fully sample an image k-space of the sample. The remainder of the MRI sequences is adjusted to under-sample the image k-space. The method further includes acquiring image k-space NMR signal datasets; estimating a sensitivity map of each of the MRI detectors using a strategy to suppress unfolding artefacts; and applying the estimated sensitivity maps to at least one of the image k-space NMR signal data sets to reconstruct a spatial image of NMR signals that are sensitive to the NMR parameter.
HYBRID PERFUSION-INTERLEAVED DIFFUSION IMAGING
Systems and methods execution of a magnetic resonance imaging pulse sequence including a first spin-echo echo planar imaging pulse sequence to acquire first data of a volume, a second spin-echo echo planar imaging pulse sequence comprising a first one or more diffusion gradient pulses to acquire first diffusion data of the volume, a third spin-echo echo planar imaging pulse sequence comprising a second one or more diffusion gradient pulses to acquire second diffusion data of the volume, and a fourth spin-echo echo planar imaging pulse sequence comprising a third one or more diffusion gradient pulses to acquire third diffusion data of the volume, generation of perfusion metrics based on the first data, and generation of diffusion metrics based on the first data, the first diffusion data, the second diffusion data, and the third diffusion data.