Abstract: A system and method to analyze image data. The image data may be used to assist in determine the presence of a feature in the image. The feature may include a bubble.

Abstract: A system and method to analyze image data. The image data may be used to assist in determine the presence of a feature in the image. The feature may include a bubble.

Abstract: Systems and methods for performing MRI include using a RF gradient field for spatial encoding. In particular implementations, |B+i|-selective pulses designed using the Shinnar-Le Roux algorithm can be provided as the excitation pulse for the RF gradient field. Further, frequency encoding for the RF gradient field can be based on the Bloch-Siegert (BS) shift. Together, these techniques can be used to support MRI based on RF gradient encoding instead of the conventional Bo encoding.

Abstract: A system and method for MR imaging is disclosed. The method causes an RF coil assembly and plurality of gradient coils to apply a fast spin echo (FSE) pulse sequence comprising a preparation segment and a plurality of refocusing segments. The FSE pulse sequence generates a pair of echoes is generated in each of the plurality of refocusing segments that comprises a first echo generated by magnetization pathways having an even number of phase inversions and a second echo generated by magnetization pathways having an even number of phase inversions. MR signals are acquired from the first echo and the second echo and an image of at least a portion of a subject of interest is reconstructed from the acquired MR signals.

Abstract: A system and method for MR imaging is disclosed. The method causes an RF coil assembly and plurality of gradient coils to apply a fast spin echo (FSE) pulse sequence comprising a preparation segment and a plurality of refocusing segments. The FSE pulse sequence generates a pair of echoes is generated in each of the plurality of refocusing segments that comprises a first echo generated by magnetization pathways having an even number of phase inversions and a second echo generated by magnetization pathways having an even number of phase inversions. MR signals are acquired from the first echo and the second echo and an image of at least a portion of a subject of interest is reconstructed from the acquired MR signals.

Abstract: Embodiments of the invention concern systems and methods for performing MRI using RF gradients for spatial encoding. One aspect of the invention involves providing |B1+|-selective pulses designed using the Shinnar-Le Roux algorithm. Another aspect of the invention involves RF encoding based on the Bloch-Siegert (BS) shift. Together, these techniques can be used to support MRI based on RF gradient encoding instead of the conventional B0 encoding.

Abstract: A system and method for focusing ultrasound into a target tissue is disclosed. The method calculates a pressure field for an array of transducer elements to generate an unaberrated pressure field matrix and causes the transducer elements to apply focused ultrasound to generate a respective aberrated pressure field at a focus location in a target tissue and surrounding volume. MR-ARFI images are acquired of the focus location and surrounding volume, a magnitude of the aberrated pressure field is measured that is generated by the applied focused ultrasound at respective focus locations in the target tissue and surrounding volume based on the MR-ARFI images, an aberration for the transducer elements is determined from the pressure field matrix and the MR-ARFI images of the focus location and the surrounding volume using a magnitude least-squares method, and a corrective phase/amplitude adjustment is applied to the transducer elements based on the determined aberrations.

Abstract: A system and method for focusing ultrasound into a target tissue is disclosed. The method calculates a pressure field for an array of transducer elements to generate an unaberrated pressure field matrix and causes the transducer elements to apply focused ultrasound to generate a respective aberrated pressure field at a focus location in a target tissue and surrounding volume. MR-ARFI images are acquired of the focus location and surrounding volume, a magnitude of the aberrated pressure field is measured that is generated by the applied focused ultrasound at respective focus locations in the target tissue and surrounding volume based on the MR-ARFI images, an aberration for the transducer elements is determined from the pressure field matrix and the MR-ARFI images of the focus location and the surrounding volume using a magnitude least-squares method, and a corrective phase/amplitude adjustment is applied to the transducer elements based on the determined aberrations.

Abstract: Proton resonance frequency shift thermometry may be improved by combining multibaseline and referenceless thermometry.

Abstract: Methods and systems for designing excitation pulses for magnetic resonance imaging are provided. One method includes parameterizing spin-domain rotation parameters to define parameterized variables and defining a constrained optimization problem based on the parameterized variables. The method also includes solving the constrained optimization problem and generating parameters for the RF pulses based on the solved problem, wherein the RF pulses are one of multidimensional RF pulses on non-constant gradient trajectories or one dimensional RF pulses on non-constant gradient trajectories.

Abstract: A system and method for radio-frequency (RF) field mapping are provided. One method includes encoding a B1 phase in at least one magnetic resonance (MR) excitation pulse as an encoded B1 phase MR excitation pulse for at least a subset of a plurality of transmit channels within a magnetic resonance imaging (MRI) system. The method also includes encoding a B1 magnitude in at least one off-resonance MR pulse as an encoded B1 magnitude off-resonance MR pulse for at least a subset of the plurality of transmit channels within the MRI system. The method further includes determining one or more composite B1 fields resulting from a transmission of the at least one encoded B1 phase MR excitation pulse and the at least one encoded B1 magnitude off-resonance MR pulse.

Abstract: The phase background of a proton resonance frequency shift treatment image may be estimated by fitting a combination of baseline images to the treatment image.

Abstract: A system and method for radio-frequency (RF) field mapping are provided. One method includes encoding a B1 phase in at least one magnetic resonance (MR) excitation pulse as an encoded B1 phase MR excitation pulse for at least a subset of a plurality of transmit channels within a magnetic resonance imaging (MRI) system. The method also includes encoding a B1 magnitude in at least one off-resonance MR pulse as an encoded B1 magnitude off-resonance MR pulse for at least a subset of the plurality of transmit channels within the MRI system. The method further includes determining one or more composite B1 fields resulting from a transmission of the at least one encoded B1 phase MR excitation pulse and the at least one encoded B1 magnitude off-resonance MR pulse.

Abstract: Methods and systems for designing excitation pulses for magnetic resonance imaging are provided. One method includes parameterizing spin-domain rotation parameters to define parameterized variables and defining a constrained optimization problem based on the parameterized variables. The method also includes solving the constrained optimization problem and generating parameters for the RF pulses based on the solved problem, wherein the RF pulses are one of multidimensional RF pulses on non-constant gradient trajectories or one dimensional RF pulses on non-constant gradient trajectories.

Abstract: The phase background of a proton resonance frequency shift treatment image may be estimated by fitting a combination of baseline images to the treatment image.

Abstract: Proton resonance frequency shift thermometry may be improved by combining multibaseline and referenceless thermometry.