Biomedical Engineering Reference
In-Depth Information
Table 10.1:
MRE comparison for the harmonic shapes in
Fig. 10.19
Standard geometric
GGVF
RAGS
% noise
snake error
snake error
snake error
0
2.00
2.00
2.00
10
2.23
2.24
2.00
20
5.00
7.07
4.03
30
10.00
16.03
3.41
40
16.16
21.31
5.22
50
15.81
21.00
5.38
60
28.17
20.10
5.83
RAGS does extremely well here, the geometric snake leaks through and the
GGVF snake leaks and fails to progress at all in the narrow object. In Fig. 10.21,
RAGS achieves a much better overall fit than the other snakes, particularly in
the lower regions of the right-hand snake and the upper-right regions of the left-
hand snake. In Fig. 10.22, again RAGS manages to segment the desired region
much better than the standard geometric and the GGVF snakes. Note the stan-
Figure 10.20: Brain MRI (
corpus callosum
) image. Top row: initial snake, stan-
dard geometric snake. Bottom row: GGVF snake and RAGS snake (original
image courtesy of GE Medical Systems).
