Repspiratory motion correction with a 2d self-navigator from bssfp dummy profiles
© Henningsson et al; licensee BioMed Central Ltd. 2011
Published: 2 February 2011
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.
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
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.
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