Patient-Specific Vascular Modeling - Microsurgery: Advances, Simulations, and Applications - page 84

or other medical imaging modalities. Vasculature lumen information
obtained from CT, MRI and other imaging modalities often contains
defects, such as distortion, partial loss, discontinuity and uniications.
And it is usually dificult to completely avoid its occurrence since in
many cases these defects are originated in the intrinsic characteristics
of the imaging modalities; for example, the dispersion of X-rays on
artifacts for CT, dependence of magnetic resonance on blood low
velocity for MRI, dispersion of contrast media for angiography and
PVE.
Here the modiication of vascular coniguration with 3D-CAD
operation plays an important role in restoring its original state. Figure
3.6 shows an instance of CAD modiication. In this representative
case, we restored the complete set of BT artery from two vascular
shapes shown in Figs. 3.6a and 3.6b, respectively, reconstructed
form CT and MRI information. Both of them lack some vascular
portion due to the characteristics of imaging modalities. Vasculature
in Fig. 3.6a is united with cranium due to PVE. Figure 3.6b lacks some
aneurismal portion due to the low velocity dependence. In those
cases, the CAD operation allows complementary merging these two
igures into one complete igure as shown in 3.6.c. This method is
also helpful to construct cerebrovascular diseases on vascular tree
with favorable coniguration, such as wide-necked aneurysms and
thin crooked stenoses, as a platform for comprehensive surgical
training and for other various purposes.

a) b) c)

Figure 3.6 An instance of restoring original vasculature igure from two

different data source, with the use of CAD: (a) 3D vasculature
igure of BT artery reconstructed from CT angiographies, some
vascular part is united with cranium due to PVE. (b) Three-
dimensional vasculature igure of BT artery reconstructed
from MRI lacks some aneurysm portion due to low velocity
dependence. (c) Complete igure of BT artery and aneurysm
restored by merging two image sources into one with the use
of CAD.