High-resolution diffusion tensor mr imaging for the evaluation of myocardial anisotropy and fiber tracking at 3 T: effect of the numbers of diffusion-sensitizing gradient directions
© Choi et al; licensee BioMed Central Ltd. 2009
Published: 28 January 2009
Diffusion tensor magnetic resonance imaging (DT-MRI) has provided a means for rapid and noninvasive evaluation of the cardiac geometry and three-dimensional fiber structure. However, most cardiac DT-MRI studies have used low diffusion resolution such as 6 directions in animal's fixed heart. To our knowledge, the effect of the numbers of diffusion-sensitizing gradient directions has not been studied for image quality of cardiac DT-MRI.
To evaluate effect of numbers of diffusion-sensitizing gradient direction on image quality for the evaluation of myocardial anisotropy and fiber tracking by using ex vivo diffusion tensor MR imaging (DT-MRI).
DT-MRI using a SENSE-based echo-planar imaging technique was acquired by using a 3 T MR scanner from ten excised heart. With a b-value of 800 s/mm2, the diffusion tensor images were obtained for 6, 15, 32 diffusion-sensitizing gradient directions at the midventricular level. For quantitative analysis, the numbers of tracked fibers, fractional anisotropy (FA), and the length of tracked fibers were measured. For qualitative analysis, two radiologists assessed the image quality of fiber tractography.
Image quality of ex vivo DT-MRI is significantly improved as the numbers of diffusion-sensitizing gradient directions increased.
This article is published under license to BioMed Central Ltd.