Abstract: Systems and methods for performing online spike recovery from multi-channel electrophysiological recordings in accordance with various embodiments of the invention are described. One embodiment of a method of performing online spike recovery from multi-channel electrophysiological recordings includes: determining a set of waveform templates; continuously obtaining multi-channel electrophysiological recordings using a multi-channel electrode; and automatically performing online spike recovery from the multi-channel electrophysiological recordings using a processing system that performs a method for sparse signal recovery that continuously adjusts a processing buffer size based upon newly obtained multi-channel electrophysiological recordings.

Abstract: 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.

Abstract: Systems and methods for performing online spike recovery from multi-channel electrophysiological recordings in accordance with various embodiments of the invention are described. One embodiment of a method of performing online spike recovery from multi-channel electrophysiological recordings includes: determining a set of waveform templates; continuously obtaining multi-channel electrophysiological recordings using a multi-channel electrode; and automatically performing online spike recovery from the multi-channel electrophysiological recordings using a processing system that performs a method for sparse signal recovery that continuously adjusts a processing buffer size based upon newly obtained multi-channel electrophysiological recordings.

Abstract: Systems and methods for producing quantitative maps of a longitudinal relaxation parameter, such as a longitudinal relaxation time (“T1”), using magnetic resonance imaging (“MRI”) are described. More particularly, a pulse sequence and imaging method for cardiac phase-resolved myocardial T1 mapping are provided.

Abstract: Systems and methods for mapping the transmit sensitivity of one or more radio frequency (“RF”) coils for use in magnetic resonance imaging (“MRI”) are described. The transmit RF field (“B1+”) for an RF coil, or an array of RF coils, is mapped using a robust, motion-insensitive technique that implements Bloch-Siegert shifts performed with interleaved positive and negative off-resonance shifts. The motion insensitivity of this technique makes it particularly useful for applications where there is significant motion, such as cardiac imaging, in which previous B1+ mapping techniques are not as accurate or effective.

Abstract: Systems and methods for late gadolinium enhancement (“LGE”) tissue viability imaging in a dynamic (e.g., temporal-ly-resolved) manner using magnetic resonance imaging (“MRI”) are provided. Dynamic LGE images can be generated throughout the entire cardiac cycle at high temporal resolution in a single breath-hold. Dynamic, semi-quantitative longitudinal relaxation maps are acquired and retrospective synthetization of dynamic LGE images is implemented using those semi-quantitative longitudinal relaxation maps.

Abstract: A system and method for controlling a magnetic resonance imaging (MRI) system to acquire images of a subject having inconsistencies in a cardiac cycle of the subject. The process includes receiving an identification of a predetermined point in a cardiac cycle of the subject and, thereupon, performing a saturation module configured to dephase magnetization within a region of interest (ROI) from before the predetermined point. The process also includes performing an inversion module configured to invert spins within the ROI and acquiring medical imaging data from the subject. A delay is inserted between the performance of the saturation module and the performance of the inversion module, wherein a duration of the delay is configured, with the saturation module, to control evidence in the medical imaging data of inconsistencies in the cardiac cycle of the subject by controlling a magnetization history of tissue in the ROI.

Abstract: An MRI method includes: performing a first data acquisition block of a pulse sequence to acquire a first MR data from a plurality of slices of a subject during a period of fully recovered longitudinal magnetization within the plurality of slices disposed at different locations in the subject; performing a second data acquisition block of the pulse sequence including a magnetization preparation module followed by a recovery period and an imaging sequence executed during the recovery period, to acquire a second MR data from the plurality of slices during the recovery period; and generating a T1 map of the subject based on the first MR data and the second MR data, of the plurality of slices.

Abstract: A system and method for obtaining magnetic resonance images are provided. The system is programmed to control the RF system to apply a saturation pulse at a reference frequency that saturates a selected labile spin species of the subject. The system is programmed to control the RF system to apply an inversion pulse after a variable delay. The system is programmed to control the RF system and the plurality of gradient coils to apply a motion sensitized driven equilibrium (MSDE) preparation pulse. The system is programmed to control the plurality of gradient coils to read imaging data during an acquisition time period. The system is programmed to reconstruct a T1 mapping image of the subject with black-blood contrast.

Abstract: 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.

Abstract: Systems and methods for producing quantitative maps of a longitudinal relaxation parameter, such as a longitudinal relaxation time (“T1”), using magnetic resonance imaging (“MRI”) are described. More particularly, a pulse sequence and imaging method for cardiac phase-resolved myocardial T1 mapping are provided.

Abstract: A system and method for obtaining magnetic resonance images are provided. The system is programmed to control the RF system to apply a saturation pulse at a reference frequency that saturates a selected labile spin species of the subject. The system is programmed to control the RF system to apply an inversion pulse after a variable delay. The system is programmed to control the RF system and the plurality of gradient coils to apply a motion sensitized driven equilibrium (MSDE) preparation pulse. The system is programmed to control the plurality of gradient coils to read imaging data during an acquisition time period. The system is programmed to reconstruct a T1 mapping image of the subject with black-blood contrast.

Abstract: Systems and methods for mapping the transmit sensitivity of one or more radio frequency (“RF”) coils for use in magnetic resonance imaging (“MRI”) are described. The transmit RF field (“B1+”) for an RF coil, or an array of RF coils, is mapped using a robust, motion-insensitive technique that implements Bloch-Siegert shifts performed with interleaved positive and negative off-resonance shifts. The motion insensitivity of this technique makes it particularly useful for applications where there is significant motion, such as cardiac imaging, in which previous B1+ mapping techniques are not as accurate or effective.

Abstract: A magnetic resonance imaging (MRI) system and methods are provided for producing images of a subject. In some aspects, a method includes identifying a point in the cardiac cycle, performing an inversion recovery (IR) pulse at a selected time point from the pre-determined point, and sampling a k-space segment at an inversion time from the IR pulse that is substantially coincident with the pre-determined point. The method also includes repeating the IR pulse and k-space sampling for multiple inversion times, and multiple segments of k-space, in an interleaved manner, to generate datasets having T1-weighted contrasts determined by their respective inversion times. The method further includes reconstructing three-dimensional (3D) spatially-aligned images using the datasets, and generating a T1 recovery map by combining the 3D images. In some aspects, a prospective/retrospective scheme may be used to obtain data fully sampled in the center of k-space and randomly undersampled in the outer regions.

Abstract: An MRI method includes: performing a first data acquisition block of a pulse sequence to acquire a first MR data from a plurality of slices of a subject during a period of fully recovered longitudinal magnetization within the plurality of slices disposed at different locations in the subject; performing a second data acquisition block of the pulse sequence including a magnetization preparation module followed by a recovery period and an imaging sequence executed during the recovery period, to acquire a second MR data from the plurality of slices during the recovery period; and generating a T1 map of the subject based on the first MR data and the second MR data, of the plurality of slices.

Abstract: A magnetic resonance imaging (MRI) system and methods are provided for producing images of a subject. In some aspects, a method includes identifying a point in the cardiac cycle, performing an inversion recovery (IR) pulse at a selected time point from the pre-determined point, and sampling a k-space segment at an inversion time from the IR pulse that is substantially coincident with the pre-determined point. The method also includes repeating the IR pulse and k-space sampling for multiple inversion times, and multiple segments of k-space, in an interleaved manner, to generate datasets having T1-weighted contrasts determined by their respective inversion times. The method further includes reconstructing three-dimensional (3D) spatially-aligned images using the datasets, and generating a T1 recovery map by combining the 3D images. In some aspects, a prospective/retrospective scheme may be used to obtain data fully sampled in the center of k-space and randomly undersampled in the outer regions.

Abstract: A system and method for controlling a magnetic resonance imaging (MRI) system to acquire images of a subject having inconsistencies in a cardiac cycle of the subject. The process includes receiving an identification of a predetermined point in a cardiac cycle of the subject and, thereupon, performing a saturation module configured to dephase magnetization within a region of interest (ROI) from before the predetermined point. The process also includes performing an inversion module configured to invert spins within the ROI and acquiring medical imaging data from the subject. A delay is inserted between the performance of the saturation module and the performance of the inversion module, wherein a duration of the delay is configured, with the saturation module, to control evidence in the medical imaging data of inconsistencies in the cardiac cycle of the subject by controlling a magnetization history of tissue in the ROI.