- Poster presentation
- Open Access
Circumferential Compression Encoding (CIRCOME) using Polar K-space
https://doi.org/10.1186/1532-429X-18-S1-P327
© Golshani and Nasiraei-Moghaddam 2016
- Published: 27 January 2016
Keywords
- Regional Myocardial Function
- Radial Spoke
- Radial Acquisition
- Circumferential Compression
- Full Cardiac Cycle
Background
Circumferential strain of the Left Ventricle gives valuable insights into regional myocardial function. This strain can be calculated from the density of radial taglines estimated by CIRCOME method [1], which benefits from direct use of tagline information in the frequency domain. CIRCOME exploits circular bandpass filters in order to selectively separate various frequencies in this region and reconstruct compression encoded images. A series of 2D filtering over a Cartesian grid is computationally expensive and also results in round-off errors. Therefore, direct extraction of the effective frequencies in k-space has a potential advantage of producing density maps faster and with higher accuracy. The purpose of this study was to investigate the feasibility of an efficient polar approach for CIRCOME method applicable on radial data acquisition in combination with an adapted Polar Fourier Transform [2].
Methods
Mid-ventricular short axis myocardial images with radial tag pattern of one healthy volunteer were acquired using a 2D segmented radial k-space trajectory on a 1.5T Siemens TIM Avanto scanner with 88, 64, and 40 radial spokes. All datasets consisted of 19 frames in a full cardiac cycle and took 11.7, 8.5 and 5.3 seconds, respectively. The radial raw data was transposed to generate the circular rings format. Each distinct circle in the annular sub-region of k-space, indicating the specific frequency of tagging modulation, was then individually used through a Hankel-based algorithm, to reconstruct an image. These images were then 2D cross-correlated in the polar coordinate system with the image obtained from the full k-space data and finally the compression encoded density maps were estimated directly in the polar domain.
Results
Tagged reconstructed image of the 6 th cardiac frame by the adapted PFT (left) and its corresponding k-space (right). The specified region demonstrates the tagging energy in the K-space.
Radial tagline density maps of the 6 th cardiac frames of one volunteer acquired through radial k-space sampling with 88 radial spokes were derived by using (a) Previously-developed CIRCOME method and (b) our proposed method. (c-d): The corresponding maps from 64 and 40-view images.
Conclusions
We have shown that the analysis of radially tagged images can become more efficient and simpler if the data is sampled through radial acquisitions. Our proposed approach will provide efficient and accurate myocardial strain assessment with high reliability.
Authors’ Affiliations
References
- Moghaddam , Finn : SPIE. Med Img Physiology. 2008Google Scholar
- Guo , Song : ISMRM. 2004Google Scholar
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/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.