Information Technology Reference
In-Depth Information
Fig. 7.
Comparison of precision and recall measures of left ventricle contours in seg-
mentation and improvement phases for 10 slices of the same heart during 1 heart cycle
4
Discussion of the Results
The conducted exepriments revealed that a preprocessing phase is able to find
a proper septum line if only a proper theshold is chosen by an expert (Fig. 2c,
Fig. 2d). Also, the segmentation phase gives satisfactory results (Fig. 3) though
in this case an additional objective analysis should be performed to evaluate the
obtained contours (approximate septum line can be evaluated visually).
As shown in [9] contours can be treated as binary classifiers of pixels. As a
result, so as to evaluate them methods of classifier evaluation can be used. In this
paper precision
P
and recall
R
are used for this purpose. For the right ventricle
they can be expressed as:
M
ri,in
∩ C
in
)
n
(
ri
=
P
(9)
M
ri,in
∩ C
in
)+
M
ri,ou
∩ C
in
)
n
(
n
(
M
ri,in
∩ C
in
)
n
(
ri
=
R
(10)
n
(
M
ri,in
∩ C
in
)+
n
(
M
ri,in
∩ C
ou
)
and for left ventricle as:
M
le,in
∩ C
in
)
n
(
le
=
P
(11)
n
(
M
le,in
∩ C
in
)+
n
(
M
le,ou
∩ C
in
)
