Eurographics/ IEEE-VGTC Symposium on Visualization 2009
H.-C. Hege, I. Hotz, and T. Munzner
(Guest Editors)
Volume 28 (2009), Number 3
Direct Visualization of Deformation in Volumes
Stef Busking, Charl P. Botha and Frits H. Post
Delft University of Technology, the Netherlands
Abstract
Deformation is a topic of interest in many disciplines. In particular in medical research, deformations of surfaces
and even entire volumetric structures are of interest. Clear visualization of such deformations can lead to important
insight into growth processes and progression of disease.
We present new techniques for direct focus+context visualization of deformation fields representing transforma-
tions between pairs of volumetric datasets. Typically, such fields are computed by performing a non-rigid regis-
tration between two data volumes. Our visualization is based on direct volume rendering and uses the GPU to
compute and interactively visualize features of these deformation fields in real-time. We integrate visualization
of the deformation field with visualization of the scalar volume affected by the deformations. Furthermore, we
present a novel use of texturing in volume rendered visualizations to show additional properties of the vector field
on surfaces in the volume.
Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional
Graphics and Realism—Raytracing I.4.7 [Image Processing and Computer Vision]: Feature Measurement—
Feature Representation
1. Introduction
Comparisons play an important role in many scientific areas.
When comparing one object to another, differences between
the two can be interpreted as deformations which transform
one object to the other. In a medical context, such defor-
mations often correlate directly to growth processes or the
progression of diseases. For this reason, analysis of defor-
mations has become an important technique for medical re-
searchers to understand these processes.
The analysis of deformation-fields with the purpose
of studying morphological changes is called deformation-
based morphometry, or DBM [AHF∗98]. DBM is primarily
promoted in brain-imaging research, where it is especially
popular as it can be used to detect morphological differences
over an entire brain. This is used, for example, to analyze all
differences between subject brains and a standard brain in
order to determine image-based characteristics that are asso-
ciated with schizophrenia [GNB∗01].
Another example illustrating the importance of volumet-
ric changes in medical data is the study of rheumatoid arthri-
tis (RA) and ostheoarthritis (OA). These are joint diseases
that affect bone and cartilage in different ways. 3D MRI is
increasingly being used to study the progression of these
diseases over time. The diseases inflict progressively more
damage on the affected joints in the form of, for exam-
ple, bone erosions, bony outgrowths called osteophytes and
changes in the cartilage. These characteristics are measured
in MRI datasets [MSC∗99, KKS∗07] and are used to track
the progression of the disease.
In all cases where 3D deformation fields have been used to
study morphological changes (mostly brain imaging), only
rudimentary visualization techniques have been applied. In
general, aggregative metrics such as Jacobian-based volume
change are calculated and used to typify differences. With
suitable visualization techniques, differences can be stud-
ied in far more detail. In other areas where 3D image-based
changes are being studied but deformation-fields are not yet
being used, such as RA and OA progression, suitable visu-
alization techniques should stimulate their introduction and
hence facilitate these studies as well.
In this paper, we present new techniques for the direct fo-
cus+context visualization of 3D deformation fields, aimed
at facilitating the study of volumetric change in medical re-
c© 2009 The Author(s)
Journal compilation c© 2009 The Eurographics Association and Blackwell Publishing Ltd.
Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK and
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