“There is a close analogy with digital camera technology; using high b-values is like having a higher quality lens, it produces a sharper image. But, to make the most of that sharpness, you need a higher resolution sensor, or, in the case of MRI, to measure more directions”.
“While a minimum of 6 directions, and a single b-value was sufficient for fitting the diffusion tensor model, measuring a much greater number of directions and a range of b-values opens up the ability to apply more sophisticated and biologically realistic models.”
According to Dr. Watts, the institute is currently acquiring data for a multicenter study focusing on adolescent brain cognitive development (ABCD), using diffusion and functional MRI to examine the development of brain regions associated with reward and risk-taking behavior in children and adolescents.1
“We now employ a fairly sophisticated diffusion sequence with a total of 104 acquisitions at a range of b-values. We are now able to run this exam with more directions and at a higher spatial resolution than our previous protocol that we used in a study focusing on Alzheimer's, while maintaining the same scan time of about 10 minutes.”
Reference
1. ABCD Study*: https://addictionresearch.nih.gov/abcd-study
* Philips is not sponsoring this study
Fiber tractography of the corticospinal tract with seed region of the posterior limb of the internal capsule. Different processing based on the same data.
CSD of multishell DWI results in the white matter FOD at each voxel. Unlike the conventional diffusion tensor model, this approach enables accurate modeling of multiple fiber populations within a single voxel.