Degree of Anistropy

[Abel, Richard L]

Dear Michael,
The degree of anisotropy is calculated as as 1 - length of the shortest axis / length of the longest axis. Doe this mean that a value of 1 is isotropic, and that the trabeculae become more preferentially aligned as the value for DA decreases?

Best Wishes
Richie

_____________________________
Dr. Richard L. Abel
Lecturer in Musculoskeletal Science
Imperial College, London.

[Michael Doube]

Hi Richie,

It's the opposite of what you suggest. As the axes approach the same
length, the equation approaches 0. In this formulation of DA, isotropy
= 0 and anisotropy = 1.

Please note that there is another calculation for DA whereby isotropy
= 1 and anisotropy = infinity (discussed in an earlier thread on this
forum). BoneJ calculates both variants, but it looks like I haven't
yet updated the documentation.

Michael

[Michael Doube]

forum). BoneJ calculates both variants, but it looks like I haven't
yet updated the documentation.

Documentation updated:
http://bonej.org/anisotropy