Biomedical Engineering Reference
In-Depth Information
Figure 2.5: Multiphase segmentation of brain MRI with region-based implicit
deformable model. (a) Diagram illustrating the definition of two phases with one
level set function. (b) Diagram illustrating the definition of 4 phases with 2
level set functions. (c) Original axial slice from 3D brain MRI data set with
initialization of the two level set functions. (d) Results of implicit deformable
model for from each phase: WM (1st line), GM (2nd line), CSF (3rd line) and
background (4th line). (e) Manually labeled data. (f) TP/FP error maps.
callosum in the brain, or cartilages of the knee, shape priors (including active
shape models, active appearance models and statistical shape descriptors) have
been used with great success in the context of constrained segmentation [47-50].
The use of an atlas (or a shape model) to assist the segmentation process
requires that the target image data and the atlas (or the model) are being aligned
via either preregistration or via a new concept of combined registration and
segmentation. When considering registration as a pre-processing step, common
atlas-based segmentation methods use warping of the atlas to the target data via
