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

## TL;DR

This paper investigates partial Fourier transform techniques in single-shot xSPEN MRI to reduce SNR penalties and improve sensitivity, demonstrating practical benefits on preclinical and human scanners.

## Contribution

It introduces novel partial Fourier methods tailored for xSPEN MRI, optimizing image quality and acquisition efficiency by exploiting the unique encoding scheme.

## Key findings

- Partial Fourier xSPEN reduces acquisition time and enhances sensitivity.
- Implementation along the xSPEN axis yields significant performance gains.
- Methods are validated on preclinical and human MRI scanners.

## Abstract

Purpose: Cross-term spatiotemporal encoding-xSPEN-is a single-shot imaging approach with exceptional resilience to field heterogeneities: its images do not require a priori information nor use post-acquisition corrections, to deliver faithfully the spatial distribution. xSPEN, however, suffers from SNR penalties due to its non-Fourier nature and due to diffusion losses- specially when desiring high resolution. This study explores partial Fourier transform approaches that acting along either the readout or the spatiotemporally-encoded dimensions, reduce these penalties. Methods: xSPEN uses an orthogonal gradient to read, in direct space, the lowbandwidth dimension. This changes substantially the nature of partial Fourier acquisitions vis-a-vis conventional imaging counterparts. A suitable theoretical analysis, however, allows one to implement these procedures along either the low-bandwidth or readout axes. Results: Partial Fourier single-shot xSPEN methods are illustrated on preclinical and human scanners. Owing to their reduction in the experimental acquisition times, these methods provide substantial sensitivity gains vis-a-vis previous implementations for a given targeted in-plane resolution. The magnitude of these gains is as expected. Conclusion: Partial Fourier approaches, particularly when implemented along the xSPEN axis, can provide substantial sensitivity advantages at minimal costs in the operation of the single-shot experiments.

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Source: https://tomesphere.com/paper/1705.09352