Information Technology Reference
In-Depth Information
Fig. 23 An axial orthogonal curved-planar cross-section CT
w¼w
c
of a 3D CT image of a scoliotic
spine, shown in a 3D view, b left sagittal view, c posterior coronal view and d superior axial view
of the image-based coordinate system (Note The image-based coordinate system and the spine
curve correspond to Figs.
1
and
7
)
3.2.2 Oblique Curved-Planar Reformation
A useful type of CPR is oblique (slanted), meaning that the orthogonal sampling
plane is rotated (inclined) for selected angles about the axes of the spine-based
coordinate system. The rotation for angles
,
w
and
/
about axes u, v and w,
respectively, of the spine-based coordinate system can be represented by rotation
matrices R
u
ð#Þ
¼
#
R
z
ð/Þ
(Eq.
54
), respectively. By applying oblique CPR to a 3D spine image, the following
oblique curved-planar cross-sections can be obtained:
R
x
ð#Þ
(Eq.
52
), R
v
ðwÞ
¼
R
y
ðwÞ
(Eq.
53
) and R
w
ð/Þ
¼
