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Designing 2D and 3D Adiabatic Pulses

详细技术说明

Multi-Dimensional Adiabatic Pulse Design Using a Sub-Pulse ApproachA new method designs and implements spatially selective, multidimensional adiabatic radio frequency (RF) pulses for use in magnetic resonance imaging (MRI). Spatially selective inversion is achieved adiabatically in both two- and three-dimensional (2D and 3D) regions of interest. The multidimensional adiabatic pulses are designed by dividing a parent adiabatic pulse into 2D selective sub-pulse elements. Selective excitation is achieved by the sub-pulses while the phases and amplitudes of the sequence of sub-pulses are prescribed according to an adiabatic full passage (the parent adiabatic pulse). The approach can be extended to 3D by applying blips along the remaining direction between sub-pulses.Complete Spatiotemporal PropertiesPrevious methods for designing a 2D adiabatic pulse use 1D amplitude-modulated sub-pulses to define a slice in one spatial direction and frequency- and amplitude-modulation of these consecutive sub-pulses to define a slice in a second spatial direction. By using 2D sub-pulses, this new approach enables 3D selection in space. By exploiting the spatiotemporal properties of this 3D excitation, it is possible to perform 3D spatiotemporally-encoded MRI (rather than exciting the entire object simultaneously). Furthermore, it offers the flexibility to choose the desired modulation method in either direction and/or to choose the desired shape of the selective excitation (square, cylinder, etc. Other advantages include significant acceleration in STEREO (scan-time), better image fidelity, compensation for B0 inhomogeneities in 1D, and volumetric slab selection for SWIFT.BENEFITS AND FEATURES:Spatially selective, multidimensional adiabatic radio frequency (RF) pulses2D and 3D adiabatic pulse designComplete spatiotemporal propertiesUses a sub-pulse approachSignificant acceleration in STEREO (scan-time)Image fidelity – better k-space trajectory to reduce saturation in center of k-spaceCan compensate for B0 inhomogeneities in 1DProvides volumetric slab selection for SWIFT (faster, higher resolution)Software implemented on MRI scannerPotentially disruptive (low-cost) technologyAPPLICATIONS:May enable anatomy specific (breast, brain) scannersCould expand customer base beyond hospitals and imaging centersSelectively exciting a desired shape adiabatically can be used in applications such as navigator, in which the pulse can be tailored to a target organ to track anatomic motion.Can be used to selectively excite a volume of interest (e.g., the heart) to permit high resolution imaging in the volume in reduced time (i.e., since the field-of-view is reduced by volume selection, the number of k-space samples required to achieve a given resolution is reduced).Phase of Development - Pilot scale demonstration

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国家/地区

美国