Introduction: High speed fMRI is desirable since it allows (1) dynamically imaging functional events; (2) reducing motion artifacts. Partial k-space (PK) imaging increases speed by collecting fewer phase encodes while preserving spatial resolution. PK can also be used in the readout direction to reduce echo time, leading to reduced flow and/or susceptibility dephasing. This study examines the feasibility of PK fMRI technique. Method: MR data were acquired on a GE 1.5 T scanner. Motor cortex activation images were obtained by running a GRE-EPI (single 4mm slice, TR/TE/FOV = 375ms/40ms/240mm, 4 shots, 160 frames in 240s, 128x128 matrix, finger apposition alternated between the left and right hands every 20s) and a 2D spiral sequence (8 slices of 3mm thickness, TR/TE/FA/FOV = 640ms/40ms/ 63o/240mm, 4 interleaves, 100 frames in 256s, resting state alternated with right hand finger tapping every 20s). The spiral data were regridded onto a 128x128 Fourier grid so that PK simulation could be carried out. PK reconstruction was performed using the homodyne approach. Results: The PK activation patterns are highly similar to that of FK. Although PK images have reduced SNR than the FK images, they don't have reduced spatial resolution nor significant ringing or blurring. Discussion and Conclusions: Our results demonstrate the feasibility of PK fMRI technique. A 2D PK technique can save nearly 1/2 scan time, while a 3D PK scan can obtain close to 4 times higher temporal resolution. The time savings can be used to collect more frames to increase statistical power or to cover more slices. The reduced time for each time frame allows using longer TR, leading to improved CNR and/or inflow charateristics. The same time per frame can be used to increase spatial resolution if so desired. Considering that PK imaging techniques are widely available, it represents a promising approach for brain functional mapping.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
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Stanford University
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Maclaren, Julian; Aksoy, Murat; Ooi, Melvyn B et al. (2018) Prospective motion correction using coil-mounted cameras: Cross-calibration considerations. Magn Reson Med 79:1911-1921
Guo, Jia; Holdsworth, Samantha J; Fan, Audrey P et al. (2018) Comparing accuracy and reproducibility of sequential and Hadamard-encoded multidelay pseudocontinuous arterial spin labeling for measuring cerebral blood flow and arterial transit time in healthy subjects: A simulation and in vivo study. J Magn Reson Imaging 47:1119-1132
Kogan, Feliks; Hargreaves, Brian A; Gold, Garry E (2017) Volumetric multislice gagCEST imaging of articular cartilage: Optimization and comparison with T1rho. Magn Reson Med 77:1134-1141
Aksoy, Murat; Maclaren, Julian; Bammer, Roland (2017) Prospective motion correction for 3D pseudo-continuous arterial spin labeling using an external optical tracking system. Magn Reson Imaging 39:44-52
Tamir, Jonathan I; Uecker, Martin; Chen, Weitian et al. (2017) T2 shuffling: Sharp, multicontrast, volumetric fast spin-echo imaging. Magn Reson Med 77:180-195
Lai, Lillian M; Cheng, Joseph Y; Alley, Marcus T et al. (2017) Feasibility of ferumoxytol-enhanced neonatal and young infant cardiac MRI without general anesthesia. J Magn Reson Imaging 45:1407-1418
Taviani, Valentina; Alley, Marcus T; Banerjee, Suchandrima et al. (2017) High-resolution diffusion-weighted imaging of the breast with multiband 2D radiofrequency pulses and a generalized parallel imaging reconstruction. Magn Reson Med 77:209-220
Uecker, Martin; Lustig, Michael (2017) Estimating absolute-phase maps using ESPIRiT and virtual conjugate coils. Magn Reson Med 77:1201-1207
Bian, W; Tranvinh, E; Tourdias, T et al. (2016) In Vivo 7T MR Quantitative Susceptibility Mapping Reveals Opposite Susceptibility Contrast between Cortical and White Matter Lesions in Multiple Sclerosis. AJNR Am J Neuroradiol 37:1808-1815
Vos, Sjoerd B; Aksoy, Murat; Han, Zhaoying et al. (2016) Trade-off between angular and spatial resolutions in in vivo fiber tractography. Neuroimage 129:117-132

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