Biomedical Engineering Reference
In-Depth Information
Figure 9.24:
Segmentation and Visualization of different data sets.
9.6.4 Results and Discussion
The technique has been applied to different data sets of MR angiography phase
contrast and time-of-flight types. For each type two volumes are used to prove
the accuracy of the technique. The first type of data is 117
×
256
×
256 (the first
two rows of Fig. 9.24) and the second type is 93
×
512
×
512 (the second two
rows of Fig. 9.24). First, level sets are initialized by automatic seed initialization.
Automatic seed initialization is used in each slice and each slice is divided into
windows of size 5
×
5. An average mean is estimated for each class from the aver-
age histogram of the volume, and signed distance functions are assigned where
each level set function is a collection of Gaussian surfaces added together with a
