- Poster presentation
- Open Access
Repspiratory motion correction with a 2d self-navigator from bssfp dummy profiles
https://doi.org/10.1186/1532-429X-13-S1-P229
© Henningsson et al; licensee BioMed Central Ltd. 2011
- Published: 2 February 2011
Keywords
- Respiratory Motion
- Motion Correction
- Phase Encode
- Respiratory Gating
- Phase Encode Direction
Introduction
Several self-navigation techniques have been proposed to improve respiratory motion compensation in CMRA. Motion estimation is, however, often impeded by static structures within the excited volume. In this work a 2D self-navigation (2DSN) method is proposed and implemented by using the dummy profiles of a 3D bSSFP sequence. To create 2DSN images we added phase encoding (PE) gradients during the start-up echoes. With this approach we can calculate foot-head motion and retrospectively perform translational correction.
Purpose
The objective of the study was to investigate the feasibility of respiratory motion correction using a novel self-navigation method and comparing it to a diaphragmatic 1D navigator (1Dnav).
Material and methods
2D self-navigation coronary MRA sequence. Phase encoded dummy profiles are used for generation of navigator image.
Two self-navigation images (sagittal view) at different respiratory phases. The white box illustrates the location of the tracked region-of-interest.
Results
CMRA of LCA for two volunteers using: (a), (d) no motion correction (b), (e) 1D navigator with 0.6 tracking factor and (c), (f) self-navigating motion correction.
Discussion and conclusion
The initial results in volunteers with the proposed self-navigation method are very promising as it provides a model-free motion correction method, which comes at no “expense” as the navigator is extracted from the dummy profiles used for magnetization preparation. Compared to other self-gating methods the main advantage of the proposed approach is that a spatial separation of the moving heart and static structures is possible. Future work will explore the use of motion correction with more degrees of freedom, e.g. affine motion, which is possible since the self-navigating method spatially encodes in 2D.
Authors’ Affiliations
Copyright
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/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.