RFOV DW/ZONAL OBLIQUE MULTISLICE (ZOOM) COMBINED/READOUT-SEGMENTED (RS)-EPI

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Diffusion-weighted imaging (DWI) using echo-planar imaging (EPI) has been limited by geometric distortion and blurring, particularly in regions with large off-resonance effects such as in the spinal-cord and in regions of the brain residing near tissue/air interfaces. Geometric distortion in EPI is proportional to the FOV in the phase encoding direction (FOVpe), as well as the echo-spacing between adjacent echoes in the EPI train (Tro). To reduce FOVpe and avoid aliasing, here we use the zonal oblique multislice EPI (ZOOM-EPI) technique, which uses a tilted refocusing pulse. To reduce distortion further, Tro can be reduced by covering k-space with a series of consecutive segments or 'blinds', known as RS-EPI. Here we implemented the ZOOM pulse together with the RS-EPI trajectory (ZOOM-RS-EPI) to get the benefits of both methods for reducing distortion.