Biomedical Engineering Reference
In-Depth Information
12
MORPHOMETRIC ANALYSIS OF NORMAL AND
PATHOLOGIC BRAIN STRUCTURE VIA
HIGH-DIMENSIONAL SHAPE
TRANSFORMATIONS
Ashraf Mohamed and Christos Davatzikos
Section of Biomedical Image Analysis, Department of Radiology
University of Pennsylvania, Philadelphia,
Pennsylvania, USA
1.
INTRODUCTION
The widespread use of neuroimaging methods in a variety of clinical and
basic science fields has created the need for systematic and highly automated im-
age analysis methodologies that extract pertinent information from images, in a
way that enables comparisons across different studies, laboratories, and image
databases. Quantifying the morphological characteristics of the brain from tomo-
graphic images, most often from magnetic resonance images (MRIs), is important
for understanding the way in which a disease can affect brain anatomy, for con-
structing new diagnostic methods utilizing image information, and for longitudinal
follow-up studies evaluating potential drugs.
The conventional type of morphological analysis of brain images has relied
on manual tracings of regions of interest (ROI) [5-22]. These methods typically
require that the reliability and repeatability of manual tracings across different
raters, but also within the same rater at different times, be established first. How-
ever, methods based on manually defined ROIs are limited in many ways. First,
