Contact: Twan Maintz
Our research in the area of medical imaging focuses on image
processing and image analysis techniques for the tasks of image
segmentation and image registration. Currently, specific projects
involve the accurate segmentation of the aortic lumen and aortic
thrombus using a model-based approach, and the improvement and
extension of current medical image registration techniques based on an
In minimally invasive surgical procedures, instruments are introduced
into the patient's body through small incisions. These procedures are
expected to have several advantages compared to traditional surgery,
such as a quick recovery of the patient, shorter hospital stay, and
the possibility to use local anesthesia.
An example of such a minimally invasive surgical procedure is the
socalled TEAM-procedure used for endovascular repair of an
Abdominal Aortic Aneurysm (AAA). TEAM stands for Transfemoral
Endovascular Aneurysm Management. In this procedure, a prosthesis is
inserted into the abdominal aorta via the femoral arteries. Insertion
is done using a delivery system, which contains a folded
prosthesis. If the prosthesis is at the right position in the aorta,
it can be deployed, using the handles and knobs on the delivery
system. Balloons are used to fix the prosthesis to the vessel
wall. The whole procedure is done under fluoroscopic image control.
To get an indication of the severity of the aneurysm and to check the
result of the operation in the long term, the volume of the thrombus
is determined. In current clinical practice, the volume is obtained by
manual delineation of the boundaries of the thrombus in every slice of
a CTA image, thus obtaining a segmentation of the thrombus.
This segmentation as well as others -such as the segmentation of the
prosthesis- is highly subjective. In this project we want to automate
the process of these segmentations, thus gaining a more objective
basis for important clinical measures. This is done using physical as
well as statisical models for shape. Please refer to the
publication list (search for e.g. 'CTA') for more details.
Coregistration -the bringing into the same coordinate reference frame-
and integration of images of the same scene but of a different
modality is an area of research that has received much attention in
the past 15 years. Demand for accurate coregistration is coming
especially from the medical community, where use of multimodal imagery
The past decennium has seen the emergence of many automated methods
for the coregistration of multimodal images, the most succesful of
which are based on statistical paradigmata that do not assume a
specific relationship between the images.
In this project, we research the use of coregistration based on mutual
information; a statistical measure (also known as the Kullback-Leibler
distance) that has been shown to be accurate for a number of
applications. The mutual information is computed from the
two-dimensional histogram of the images involved, see the images below
for an example. For more details, please refer to our
publication list (search e.g. for 'registration').
An incomplete list of master and other projects (in Dutch) can be
. Contact Twan
Maintz for more information.
webmaster: Twan Maintz