Volume 14 Supplement 1
Polar HARP for the polar CMR tagging
© Babaee and Moghaddam; licensee BioMed Central Ltd. 2012
Published: 1 February 2012
The polar coordinate system adapts best to the morphology of the heart. The recently developed sequences that allow the CMR Tagging in the circular and radial directions facilitate the calculation and presentation of the myocardium mechanics. Development of the corresponding processing methods is required to further enhance the utilization of these sequences. Here we suggest a processing method based on the harmonic phase approach to obtain the high-resolution motion in polar coordinate system.
Using a half circular bandpass filtering of K-Space, the magnitude and phase images of the fundamental frequency were reconstructed in the circular images. For the radial images a series of narrow bandpass filters were applied for different regions. The harmonic phase images were then unwrapped and adjusted for original and deformed images. Finally the amount of displacement in the direction normal to the taglines was calculated based on the location of pixels with similar phase.
We have shown that the harmonic phase approach can be utilized in images with densely distributed polar tagging to obtain the high-resolution motion automatically. The technique has wide potential applications in acquired and congenital heart diseases.
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.