This document discusses the validation of a deformable image registration technology. It provides an example where a fixed geometry is pressure loaded, resulting in bending deformation. The unloaded and loaded geometries serve as a template and target image. The warping registration analysis only uses these two images to determine deformation and strain, and the results are compared to finite element analysis to ensure accuracy. This validation demonstrates the ability of the technique to accurately capture edge and internal deformations using intensity gradients between images.

1. A FINITE ELEMENT BASED
DEFORMABLE IMAGE REGISTRATION
TECHNOLOGY CONTINUED
Alexander I. Veress, Ph.D.

2. Validation of Deformable Image
Registration - Warping
 This technology has been validated for use with
ultrasound, MRI, PET and SPECT imaging.
 What follows is a simple problem that illustrates the
steps involved in the validation.

3. Initial validation were based on
images derived from forward FEA
models.
A geometry is fixed
(right side) and pressure
loaded (left side). This
loading results in a
bending deflection. Unloaded geometry Loaded geometry
Template image Target image

4. Loading of deformable image analysis - warping
The only loading for the warping registration analysis result
from the template and target images.
While more than two images can be used in the analysis for
this example only two images (below) were utilized.
Template image Target image

5. Comparison of results: Deformation and strain
were then compared to ensure that the results
are identical.
Forward Warping
Total displacement

6. Comparison of results: Deformation and strain
were then compared to ensure that the results
are identical.
Forward Warping
Effective strain

7. Discussion
 This particular validation run was edge based. In other
words the intensity gradient representing the edges of
the object provided the complete loading on the
system.
 In other problems, intensity gradients within the
boundary of the object serve as fiducial points for the
analysis. Below are unloaded (left) and loaded (right)
cartilage cell nuclei.
Template Target
Henderson et al. Direct Measurement of Intranuclear Strain Distributions and RNA Synthesis in
Single Cells Embedded within NativeTissue. Biophysical Journal, 105(10):2252-61, 2013.

8. Validation papers
 Veress AI, Klein G, and GullbergGT. A Comparison of HyperelasticWarping of PET
Images withTagged MRI for the Analysis of Cardiac Deformation. International Journal
of Biomedical Imaging. Article ID 728624, 14 pages, 2013.
 Phatak NS, Maas SA, Veress AI, Pack NA, Di Bella EV,Weiss JA. Strain measurement in
the left ventricle during systole with deformable image registration. Medical Image
Analysis. 13(2):354-61, 2009.
 Phatak NS, Sun Q, Kim SE, Parker DL, Kent Sanders R, Veress AI, Ellis BJ, and Weiss JA.
Noninvasive Determination of Ligament Strain with Deformable Image Registration.
Annals of Biomedical Engineering. 35(7):1175-87, 2007.
 Veress AI, GullbergGT, and Weiss JA. Measurement of Strain in the LeftVentricle
during Diastole with cine-MRI and Deformable Image Registration. Journal of
Biomechanical Engineering. 127(7):1195-207, 2005.
 Veress AI,Weiss JA, GullbergGT,Vince DG, and Rabbitt RD. Strain Measurement in
Coronary Arteries Using Intravascular Ultrasound and Deformable Images. Journal of
Biomechanical Engineering. 124:734-741, 2003.