- Poster presentation
- Open Access
Real time circular tagging is possible through radial acquisition
© Golshani and Nasiraei-Moghaddam 2016
- Published: 27 January 2016
- Phantom Data
- Radial Spoke
- Radial Acquisition
- Nyquist Sampling Rate
- Undersampling Factor
Real-time capturing of the myocardial function through CMR tagging is of great clinical importance. In circular tagging, tagline information manifests itself in k-space in an annular sub-region. This k-space characteristic in combination with polar acquisition schemes can be exploited to speed up the imaging. In our previous works, we showed that by selectively acquiring only this portion of k-space through circular sampling, it is feasible to capture tagline information with an acceleration factor of 8 . We further described a coherent acquisition/reconstruction approach for radial tagging based on radial sampling of k-space . In this study, we investigated the feasibility of that approach for circular tagging and evaluated its performance on phantom as well as human tagged images acquired with various numbers of radial projections.
MR images with circular tag pattern were acquired from phantom as well as a healthy volunteer through a radial k-space sampling scheme on a 1.5T Siemens TIM Avanto scanner. The phantom data was collected with 504 radial spokes to fulfill the Nyquist sampling rate for a 192192 image matrix which prescribes acquisition of 302 projections. The in-vivo data, acquired with 88 views in 11 heartbeats, consists of 19 frames of a mid-ventricular short axis slice. A Hankel-based algorithm referred to as Polar Fourier Transform (PFT) is implemented for reconstruction of the acquired polar data. To study the performance of the method on undersampled datasets, we subsampled the raw datasets to a much lower extent than the Nyquist rate varying from 252 to 18.
The PFT method in combination with radial k-space sampling is highly consistent and robust for circular tagging enabling undersampling factors of 16 that can be exploited towards real-time cardiac imaging. In contrast to commonly used reconstruction techniques for radial acquisitions, which su?er from severe streaking artifacts with undersampled projections, the overall appearance of PFT images even for extreme undersampling is of diagnostic quality.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.