Biomedical Engineering Reference
In-Depth Information
Figure 6
. Fiber anisotropy A(
x
) estimated from DTMRI data, and calculated as
2
2
2
()
x
( ]
x
()
x
( ]
x
()
x
( ]
x
[
M
M
+
[
M
M
+
[
M
M
()
, where M
1,2,3
(
x
) are diffusion tensor
x
1
2
1
3
2
3
A
=
2
2
2
()
x
()
x
()
x
M
+
M
+
M
1
2
3
eigenvectors at voxel
x
, in normal (
A
) and failing (
C
) canine heart. Fiber inclination angle
computed using DTMRI in normal (
B
) and failing (
D
) heart. Panels
A
and
B
are the same
normal, and panels
C
and
D
the same failing heart.
Representative results from imaging of one normal and one failing canine
heart are shown in Figure 6. Figures 6A,C are short-axis basal sections taken at
approximately the same level in normal (6A) and failing (6C) canine hearts.
These two plots show regional anisotropy according to the indicated color code.
Figures 6B,D show the angle of the primary eigenvector relative to the plane of
section (inclination angle), according to the indicated color code, for the same
sections as in Figures 6A,C. Inspection of these data show: (a) the failing heart
