Biomedical Engineering Reference
In-Depth Information
The effects of motion correction are illustrated for one patient in Fig.
2.11
.
The reference phase
in mid-expiration and diastole is shown in Fig.
2.11
a. One
particular template image
R
out of the 24 remaining gates is shown in Fig.
2.11
b.
We chose the gate in maximum inspiration and systole which is very dissimilar
to
T
. Volume
changes induced by this transformation are visualized in Fig.
2.11
c. After applying
the estimated transformation to
R
. The grid representing the estimated transformation is overlaid on
T
with the mass-preserving transformation model
we obtain the image shown in Fig.
2.11
d. The absolute difference images before and
after applying the estimated transformation are given in Fig.
2.11
e, f. Combining all
25 motion corrected gates yields the final image in Fig.
2.11
g. A clear reduction of
motion induced blurring can be observed compared to the image without motion
correction in Fig.
2.11
h.
T
Fig. 2.11
(
a
)using
V
AMPIRE
resulting in (
d
). The absolute difference image before (
e
) and after motion correction (
f
)
illustrate the accuracy. The estimated transformation
y
(
b
) is smooth and free of foldings which can
also be seen at the plot of the Jacobian map (
c
). The logarithmic color map ranges from 0
.
5(
blue
)
over 1 (
white
)to2(
red
). The
bottom row
shows the final image with (
g
) and without (
h
) motion
correction. (The images are taken from [
51
].
c
Effects of motion correction illustrated for one patient. (
b
)isregisteredto
R
2011 IEEE. Colored figures are only available in
the online version.)
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