University of California

Eric C Wong

Jia Guo

Thomas T Liu

James R Heath

James Fraser Stoddart

Charles Patrick Collier

Youngkyoo Jung

Francisco M Raymo

Gunter Mattersteig

Techniques, systems and apparatus are described for magnetic resonance imaging by modifying the shape/thickness of an excitation/inversion slab. For instance, the inversion slab can be shaped as a wedge to improve temporal signal-to-noise ratio (tSNR) of arterial spin labeling (ASL) experiments by matching the temporal bolus width with the inter-pulse spacing in different feeding arteries. The shape/thickness of the excitation/inversion slab across the X-Y plane can be modified by modulating the movement of the 'on-resonance' plane in space by the combination of conventional slice-selective (SS) adiabatic fast passage (AFP) and additional in-plane gradient pulses. Using this method, a computer can generate different shapes of the excitation/inversion slab.

Magnetic resonance imaging based on altering the shape of the inversion region in pulsed arterial spin labeling

Methods, systems and apparatus for magnetic resonance imaging that facilitate applying a gradient waveform to generate a k-space trajectory in a subject, applying radio frequency (RF) pulses having a pseudorandom phase distribution, such that the RF pulses are applied to the subject at a plurality of non-uniform locations near a center of the k-space trajectory and collecting, based on the applied RF pulses and the applied gradient waveform, imaging data from the subject.

Magnetic resonance imaging using randomized radio frequency pulses

Techniques, systems computer program products are disclosed for mapping of vascular perfusion territories by applying a train of pseudo-continuous radio frequency tagging pulses to modulate a first magnetization of one or more blood vessels that supply blood to one or more vascular perfusion territories, applying an encoding scheme using unipolar transverse gradient pulses to modulate a second magnetization of blood vessels of the vascular perfusion territories, obtaining efficiency for each blood vessel based on the applied encoding scheme and separating the vascular perfusion territories by using the obtained tagging efficiency in a decoding process.

Mapping vascular perfusion territories using magnetic resonance imaging

Techniques, systems and apparatus are described for magnetic resonance imaging. A magnetic resonance imaging (MRI) system comprises a scanner comprising a magnet, gradient coils and a radio frequency (RF) system to perform various operations. The scanner can apply a gradient field and a train of RF pulses comprising more than two phases to tag a target blood vessel, and acquire magnetic resonance signals based on the applied train of RF pulses to sample the more than two phases. The MRI system includes a data processing system in communication with the scanner to receive the acquired magnetic resonance signals and process the received magnetic resonance signal to generate images proportional to perfusion.

Multi-phase pseudo-continuous arterial spin labeling

Techniques, systems computer program products are disclosed increasing tagging efficiency in velocity selective arterial spin labeling using multiple velocity selective saturation modules. In one aspect, a magnetic resonance imaging method for tagging arterial blood includes using two or more velocity selective saturation (VSS) modules to tag arterial blood. The tagged arterial blood is imaged.

Increasing the perfusion signal to noise ratio (SNR) in velocity selective arterial spin labeling (VSASL) in magnetic resonance imaging

Techniques, systems and computer program products are disclosed for mapping of vascular perfusion territories by placing one or more blood vessels of the vascular perfusion territories in a tag condition and others in a control condition by applying a train of pseudo-continuous radio frequency tagging pulses. In addition, an encoding scheme is applied to fully invert or relax the blood vessels of the vascular perfusion territories. Also, a tagging efficiency is measured for each blood vessel based on the applied encoding scheme. Further, the vascular perfusion territories are separated by using the measured tagging efficiency in a decoding process.

Mapping of vascular perfusion territories

Techniques for providing velocity-selective magnetic arterial spin labeling in magnetic resonance imaging (MRI) without spatial selectivity. In one implementation, an RF pulse train is applied to selectively tag spins according to velocities of the spins without selection based on locations of the spins. MRI images of tagged spins at an area of interest are then acquired to obtain information on perfusion at the area of interest.

Velocity-selective arterial spin labeling without spatial selectivity

Volatile and non-volatile solid state molecular switching devices which are electrically addressable and may be used in memory cells, routing circuits, inverters and field programmable devices which may or may not be designed to exhibit diode behavior. The molecular switching devices include certain &lsqb;2&rsqb; catenanes as bistable molecules which are sandwiched between two switch terminals. The switches are extremely small and have dimensions which range from several microns down to a few nanometers.

Growing community of inventors

Del Mar, CA, United States of America

Eric C Wong