Biomedical Engineering Reference
In-Depth Information
Regarding MRI brain imaging, the paper in [72] gives a very nice review of the
potential applications of MRI in quantification of brain disease. The brain cortex
is a highly convoluted layer of gray matter that lies between the white matter
and the cerebrospinal fluid (CSF). Clinical applications require reconstruction
of the cerebral cortex from MRI data for:
1. brain visualization
2. analysis of brain geometry
3. registration with other data sets (multimodality or repetitive scans of a
single patient)
4. surgical planning
5. cortex mapping
The interface between WM and GM is clearly visible on T1-weighted MRIs. Diffi-
culties of MRI segmentation arise from imaging noise, inhomogeneities, partial
volume effects and the highly convoluted geometry of the cortex.
Regarding quantitative measurements of the brain anatomy [33] using MRI,
whole brain volume, cortical gray matter volume, white matter volume, corti-
cal surface area, cortical shape characteristics and cortical thickness map are
among the most interesting to study brain anatomy and function. Such measure-
ments can typically assist in characterizing, predicting or assessing neurological
and psychiatric disorders via correlation to abnormality in the measurements.
These measurements are all easily derived from the final level set function in a
distance-preserving framework (typically ensured by reinitialization of the level
set function during the iterative deformation process).
Two sources of MRI brain data for testing segmentation algorithms are avail-
able as open source databases on the web:
The
Internet Brain Segmentation Repository
(IBSR) available
at http://www.cma.mgh.harvard.edu/ibsr/. This repository provides
manually-guided expert segmentation results along with magnetic reso-
nance brain image data. Its purpose is to encourage the evaluation and
development of segmentation methods. The IBSR is supported by the
National Institute of Neurological Disorders and Stroke at the NIH part
of a grant that funds research in MR brain segmentation by researchers
