Partial Fourier techniques in single-shot cross-term spatiotemporal encoded MRI

Area of Science:

• Magnetic Resonance Imaging
• Medical Physics
• Image Reconstruction

Background:

• Cross-term spatiotemporal encoding (xSPEN) offers robust 2D spatial imaging, immune to field heterogeneities.
• xSPEN faces signal-to-noise ratio (SNR) limitations due to its non-Fourier nature and diffusion losses, particularly at high resolutions.

Purpose of the Study:

• To investigate the application of partial Fourier transform techniques to mitigate SNR penalties in xSPEN.
• To explore partial Fourier implementation along readout or spatiotemporally encoded dimensions.

Main Methods:

• Developed theoretical analysis for partial Fourier xSPEN acquisitions.
• Implemented partial Fourier transforms along either the spatiotemporal or readout axes.
• Acquired partial Fourier single-shot xSPEN images on preclinical and human scanners.

Main Results:

• Partial Fourier xSPEN significantly reduced acquisition times.
• Achieved substantial sensitivity gains compared to conventional xSPEN for a given resolution.
• Demonstrated the physical origins of these sensitivity improvements.

Conclusions:

• Partial Fourier approaches, especially along the low-bandwidth spatiotemporal dimension, offer significant sensitivity advantages for xSPEN.
• These methods provide several-fold sensitivity gains with minimal impact on experiment execution and processing.
• The findings facilitate higher resolution and more sensitive single-shot imaging.