Abstract: Systems and methods for producing an image of a subject with a magnetic resonance imaging (MRI) system. The method includes acquiring first MRI data from the subject using a first coil having a first field of view (FOV), simultaneously with or sequentially with acquiring the first MRI data, acquiring second MRI data from the subject using a second coil having a second FOV that is non-overlapping with the first FOV, and reconstructing images of the subject from the first MRI data and the second MRI data.

Abstract: Multi-echo radio frequency (“RF”) gradient based magnetic resonance imaging (“MRI”) is described. A gradient is established in the B1 RF field to enable B1-encoded pulse sequences, such as B1-encoded spin-echo pulse sequences. As a non-limiting example, the B1-field gradient can be established using a multi-echo frequency-modulated Rabi encoded echoes (“ME-FREE”) technique.

Abstract: Spin resonance spectroscopy and/or imaging is achieved using a system that combines longitudinal (e.g., along the z-axis) detection with a modulated fictitious field generated by a transverse plane (e.g., xy-plane) RF field. Based on z-axis detection of magnetization polarized by this fictitious field as it is modulated (e.g., modulated on and off, or otherwise), spin resonance signals (e.g., EPR, NMR) are measurable with high isolation simultaneous transmit and receive capability. Additionally or alternatively, spin relaxation times can be measured using the described systems.

Abstract: Accelerated data acquisition using two-dimensional (“2D”) radio frequency (“RF”) pulse segments as virtual receivers for a parallel image reconstruction technique, such as GRAPPA, is provided. Data acquisition is accelerated using segmented RF pulses for excitation, refocusing, or both, and undersampling k-space along a dimension of the RF pulse segments. In this way, parallel image reconstruction techniques, such as GRAPPA, can be adapted to work with a single RF receive coil. By undersampling the data acquisition and finding correlations between the data from different segments, unsampled data can be recovered. This shortens scan times, yielding the advantages of segmented pulses without the formerly required long scans.

Abstract: Accelerated data acquisition using two-dimensional (“2D”) radio frequency (“RF”) pulse segments as virtual receivers for a parallel image reconstruction technique, such as GRAPPA, is provided. Data acquisition is accelerated using segmented RF pulses for excitation, refocusing, or both, and undersampling k-space along a dimension of the RF pulse segments. In this way, parallel image reconstruction techniques, such as GRAPPA, can be adapted to work with a single RF receive coil. By undersampling the data acquisition and finding correlations between the data from different segments, unsampled data can be recovered. This shortens scan times, yielding the advantages of segmented pulses without the formerly required long scans.

Abstract: Systems and methods for simultaneous radio frequency (“RF”) transmission and reception for nuclear magnetic resonance applications, such as magnetic resonance imaging (“MRI”) are described. The system includes a simultaneous transmit and receive (“STAR”) control system that compensates for the effects of load changes in a radio frequency (“RF”) coil due to the inevitable motion of living subjects (e.g., from subject motion, respiration, swallowing). The system also maintains a high transmit-receive isolation, even when scanning a subject using a continuous RF broad band sweep excitation.

Abstract: Described here are systems and methods for magnetic resonance imaging (“MRI”) using a sweeping frequency excitation applied during a time-varying magnetic field gradient. As an example, a gradient-modulated offset independent adiabaticity (“GOIA”) approach can be used to modify the pattern of the sweeping frequency excitation. Data are acquired as time domain signals and processed to generate images. As an example, the time domain signals are processed using a correlation between a Fourier transform of the gradient-modulated sweeping frequency excitation and a Fourier transform of the time domain signals.

Abstract: A method for acquiring magnetic resonance imaging data from a subject. The method includes performing a series of radio frequency pulses formed of individual RF pulses applied with a constant time interval between each of the individual RF pulses to form a consistent magnetic field about at least of a region of interest in the subject, where the RF pulse has a flip angle of less than 30 degrees. The method also includes performing phase encoding gradients to achieve spatial encoding and performing an imaging acquisition process over an acquisition window to acquire imaging data. The method further includes performing phase encoding rephasing gradients and repeating the preceding steps such that a time between a center of the acquisition window and a center of a first RF pulse in a first RF pulse in a repetition of the RF pulses is equal to the constant pulse interval.

Abstract: A method for acquiring magnetic resonance imaging data from a subject. The method includes performing a series of radio frequency pulses formed of individual RF pulses applied with a constant time interval between each of the individual RF pulses to form a consistent magnetic field about at least of a region of interest in the subject, where the RF pulse has a flip angle of less than 30 degrees. The method also includes performing phase encoding gradients to achieve spatial encoding and performing an imaging acquisition process over an acquisition window to acquire imaging data. The method further includes performing phase encoding rephasing gradients and repeating the preceding steps such that a time between a center of the acquisition window and a center of a first RF pulse in a first RF pulse in a repetition of the RF pulses is equal to the constant pulse interval.

Abstract: Described here are systems and methods for designing and implementing spatially selective, multidimensional adiabatic radio frequency (“RF”) pulses for use in magnetic resonance imaging (“MRI”). Spatially selective inversion can be achieved adiabatically in both two-dimensional (“2D”) and three-dimensional (“3D”) regions-of-interest. The multidimensional adiabatic pulses are generally designed using sub-pulses that are adiabatically driven using a parent adiabatic pulse.

Abstract: Systems and methods for magnetic resonance imaging (“MRI”) using a frequency swept excitation that utilizes multiple sidebands to achieve significant increases in excitation and acquisition bandwidth are provided. The imaging sequence efficiently uses transmitter power and has increased sensitivity as compared to other techniques used for imaging of fast relaxing spins. Additionally, the imaging sequence can provide information about both fast and slow relaxing spins in a single scan. These features are advantageous for numerous MRI applications, including musculoskeletal imaging, other medical imaging applications, and imaging materials.

Abstract: Systems and methods for pointwise encoding time reduction with radial acquisition (“PETRA”) magnetic resonance imaging (“MRI”) using a gradient modulation scheme to enable higher readout bandwidth while keeping the missing samples of the central region of k-space small are provided. This acquisition scheme allows independent selection of the excitation and readout bandwidths, which allows a higher readout bandwidth while keeping the required number of missing central k-space samples low. This flexibility in selecting the excitation and readout bandwidth settings can mitigate the peak radio frequency power and specific absorption rate limitations on flip angle in traditional PETRA imaging schemes.

Abstract: Systems and methods for simultaneous radio frequency (“RF”) transmission and reception for nuclear magnetic resonance applications, such as magnetic resonance imaging (“MRI”) are described. The system includes a simultaneous transmit and receive (“STAR”) control system that compensates for the effects of load changes in a radio frequency (“RF”) coil due to the inevitable motion of living subjects (e.g., from subject motion, respiration, swallowing). The system also maintains a high transmit-receive isolation, even when scanning a subject using a continuous RF broad band sweep excitation.

Abstract: Described here are systems and methods for designing and implementing spatially selective, multidimensional adiabatic radio frequency (“RF”) pulses for use in magnetic resonance imaging (“MRI”). Spatially selective inversion can be achieved adiabatically in both two-dimensional (“2D”) and three-dimensional (“3D”) regions-of-interest. The multidimensional adiabatic pulses are generally designed using sub-pulses that are adiabatically driven using a parent adiabatic pulse.

Abstract: Systems and methods for magnetic resonance imaging (“MRI”) using a frequency swept excitation that utilizes multiple sidebands to achieve significant increases in excitation and acquisition bandwidth are provided. The imaging sequence efficiently uses transmitter power and has increased sensitivity as compared to other techniques used for imaging of fast relaxing spins. Additionally, the imaging sequence can provide information about both fast and slow relaxing spins in a single scan. These features are advantageous for numerous MRI applications, including musculoskeletal imaging, other medical imaging applications, and imaging materials.

Abstract: A system and method for producing an image using a radio frequency (RF) coil in a magnetic resonance imaging system (MRI). A static magnetic field (B0) extends across a first and second region of interest (ROI). A local radio frequency (RF) coil, shaped like a dental arch, is positioned proximate to the ROIs, the ROIs being the upper and lower jaw of a subject. The RF coil and the subject are oriented in the static magnetic field (B0) to align an axis extending through a loop of the coil with the B0 direction of the static magnetic field extending across the ROIs. A pulse sequence is then performed with the MRI system and the RF coil to acquire imaging data from the ROIs simultaneously while using a transverse component of an excitation field (B1). The image data is reconstructed to create an image of the ROIs.

Abstract: Systems and methods for pointwise encoding time reduction with radial acquisition (“PETRA”) magnetic resonance imaging (“MRI”) using a gradient modulation scheme to enable higher readout bandwidth while keeping the missing samples of the central region of k-space small are provided. This acquisition scheme allows independent selection of the excitation and readout bandwidths, which allows a higher readout bandwidth while keeping the required number of missing central k-space samples low. This flexibility in selecting the excitation and readout bandwidth settings can mitigate the peak radio frequency power and specific absorption rate limitations on flip angle in traditional PETRA imaging schemes.

Abstract: Described here are systems and methods for magnetic resonance imaging (“MRI”) using a sweeping frequency excitation applied during a time-varying magnetic field gradient. As an example, a gradient-modulated offset independent adiabaticity (“GOIA”) approach can be used to modify the pattern of the sweeping frequency excitation. Data are acquired as time domain signals and processed to generate images. As an example, the time domain signals are processed using a correlation between a Fourier transform of the gradient-modulated sweeping frequency excitation and a Fourier transform of the time domain signals.

Abstract: A system and method for producing an image using a radio frequency (RF) coil in a magnetic resonance imaging system (MRI). A static magnetic field (B0) extends across a first and second region of interest (ROI). A local radio frequency (RF) coil, shaped like a dental arch, is positioned proximate to the ROls, the ROls being the upper and lower jaw of a subject. The RF coil and the subject are oriented in the static magnetic field (B0) to align an axis extending through a loop of the coil with the B0 direction of the static magnetic field extending across the ROls. A pulse sequence is then performed with the MRI system and the RF coil to acquire imaging data from the ROls simultaneously while using a transverse component of an excitation field (B1). The image data is reconstructed to create an image of the ROls.

Abstract: A method of magnetic resonance is provided that uses a frequency swept excitation wherein the acquired signal is a time domain signal is provided. In one embodiment, the method comprises, applying a sweeping frequency excitation and acquiring a time domain signal. The sweeping frequency excitation has a duration and is configured to sequentially excite isochromats having different resonant frequencies. Acquisition of the time domain signal is done during the duration of the sweeping frequency excitation. The time domain signal is based on evolution of the isochromats.