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Figure from:Three-dimensional brain atlas of anatomy and vasculature

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Figure 2. Radius processing. (a) Graph illustrates the distribution of radial measurements along a sample ves- sel segment before and after smoothing. (b, c) Histo- grams show the distribution of radial measurements be- fore (b) and after (c) smoothing.

Figure 2 Radius processing. (a) Graph illustrates the distribution of radial measurements along a sample ves- sel segment before and after smoothing. (b, c) Histo- grams show the distribution of radial measurements be- fore (b) and after (c) smoothing.

Related Figures (7)

Figure 1. Vessel segmentation. Original axial MR angiographic image (left) is shown after enhance: ment (center), with segmented vessels displayed before manual editing (right).
Figure 1. Vessel segmentation. Original axial MR angiographic image (left) is shown after enhance: ment (center), with segmented vessels displayed before manual editing (right).
After skeletonization, the radius along the cen- terline is scattered due to noise and the partial volume averaging effect (Fig 2a). It is known from anatomic studies that vessel radius decreases gradually (about 5%—10%) as one moves in the direction of blood flow. Hence, to perform radius smoothing, the direction of blood flow was first determined, followed by the removal of radius outliers. The variability of the radius along a blood vessel was plotted on a graph that gives the vessel radius as a function of distance along the centerline between consecutive bifurcations (ie, for a vessel segment) (Fig 2a). By studying several such graphs, we observed that the radius consis- tently changes slowly in the middle part of the vessel segment and more rapidly (over 20%) at the ends (ie, at the bifurcations [Fig 2a]). We also created a histogram illustrating the distribution of radius measurements (Fig 2b). The radius with
After skeletonization, the radius along the cen- terline is scattered due to noise and the partial volume averaging effect (Fig 2a). It is known from anatomic studies that vessel radius decreases gradually (about 5%—10%) as one moves in the direction of blood flow. Hence, to perform radius smoothing, the direction of blood flow was first determined, followed by the removal of radius outliers. The variability of the radius along a blood vessel was plotted on a graph that gives the vessel radius as a function of distance along the centerline between consecutive bifurcations (ie, for a vessel segment) (Fig 2a). By studying several such graphs, we observed that the radius consis- tently changes slowly in the middle part of the vessel segment and more rapidly (over 20%) at the ends (ie, at the bifurcations [Fig 2a]). We also created a histogram illustrating the distribution of radius measurements (Fig 2b). The radius with
Figure 3. Bifurcation surface refinement with B-subdivision. Three-dimensional images illustrate steps 0 (left), 1 (center), and 2 (right).
Figure 3. Bifurcation surface refinement with B-subdivision. Three-dimensional images illustrate steps 0 (left), 1 (center), and 2 (right).
Figure 4. User interface. Screen shows the atlas viewing area, anatomic (top right) and vasculat (bottom right) indexes, atlas navigation panel (top), and control panel (left).
Figure 4. User interface. Screen shows the atlas viewing area, anatomic (top right) and vasculat (bottom right) indexes, atlas navigation panel (top), and control panel (left).
Figure 5. Selection of multiple structures. Screens show selection of all anatomic structures (a) and all vascular segments (b), some of which are labeled in each case.
Figure 5. Selection of multiple structures. Screens show selection of all anatomic structures (a) and all vascular segments (b), some of which are labeled in each case.
Figure 6. Selection of individual structures. Atlas viewing area displays the corpus callosum, together with all vascular segments.
Figure 6. Selection of individual structures. Atlas viewing area displays the corpus callosum, together with all vascular segments.
Figure 7. Detailed depiction of combined structures. Atlas viewing area demonstrates the circle of Willis and the surrounding anatomy.
Figure 7. Detailed depiction of combined structures. Atlas viewing area demonstrates the circle of Willis and the surrounding anatomy.