Multiple-coil k-space interpolation enhances resolution in single-shot spatiotemporal MRI

TL;DR

This paper introduces a method called SUSPENSE that uses multiple receivers in single-shot SPEN MRI to achieve super-resolution imaging with sub-millimeter in-plane resolution, without increasing sequence complexity.

Contribution

The authors propose a novel multi-receiver interpolation technique for SPEN MRI that enhances resolution akin to multi-shot methods but within a single scan.

Findings

Achieved sub-mm in-plane resolution in single-shot SPEN MRI.

Demonstrated resolution enhancement on phantoms and human volunteers.

Enabled full-brain coverage at high resolution in 3 seconds.

Abstract

Purpose: Spatio-temporal encoding (SPEN) experiments can deliver single-scan MR images without folding complications and with robustness to chemical shift and susceptibility artifacts. It is here shown that further resolution improvements can arise by relying on multiple receivers, to interpolate the sampled data along the low-bandwidth dimension. The ensuing multiple-sensor interpolation is akin to recently introduced SPEN interleaving procedures, albeit without requiring multiple shots. Methods: By casting SPEN's spatial rasterization in k-space, it becomes evident that local k-data interpolations enabled by multiple receivers are akin to real-space interleaving of SPEN images. The practical implementation of such resolution-enhancing procedure becomes similar to those normally used in SMASH or SENSE, yet relaxing these methods' fold-over constraints. Results: Experiments validating the theoretical expectations were carried out on phantoms and human volunteers on a 3T scanner. The experiments showed the expected resolution enhancement, at no cost in the sequence's complexity. With the addition of multibanding and stimulated echo procedures, 48-slices full-brain coverage could be recorded free from distortions at sub-mm resolution, in 3 sec. Conclusion: Super-resolved SPEN with SENSE (SUSPENSE) achieves the goals of multi-shot SPEN interleaving within one single scan, delivering single-shot sub-mm in-plane resolutions in scanners equipped with suitable multiple sensors.