Various multi-center trials have shown that cardiac resynchronization therapy (CRT) is an effective procedure
for patients with end-stage drug invariable heart failure (HF). Despite the encouraging results of CRT, at least
30% of patients do not respond to the treatment. Detailed knowledge of the cardiac anatomy (coronary
venous tree, left ventricle), functional parameters (i.e. ventricular synchronicity) is supposed to improve
CRT patient selection and interventional lead placement for reduction of the number of non-responders.
As a pre-interventional imaging modality, cardiac magnetic resonance (CMR) imaging has the potential
to provide all relevant information. With functional information from CMR optimal implantation target
sites may be better identified. Pre-operative CMR could also help to determine whether useful vein target
segments are available for lead placement. Fused with X-ray, the mainstay interventional modality, improved
interventional guidance for lead-placement could further help to increase procedure outcome.
In this contribution, we present novel and practicable methods for a) pre-operative functional and anatomical
imaging of relevant cardiac structures to CRT using CMR, b) 2D-3D registration of CMR anatomy and
functional meshes with X-ray vein angiograms and c) real-time capable breathing motion compensation for
improved fluoroscopy mesh overlay during the intervention based on right ventricular pacer lead tracking.
With these methods, enhanced interventional guidance for left ventricular lead placement is provided.
Minimally invasive catheter ablation procedures are guided by biplane fluoroscopy images visualising the interventional
scene from two different orientations. However, these images do not provide direct access to their
inherent spatial information. A three-dimensional reconstruction and visualisation of the catheters from such
projections has the potential to support quick and precise catheter navigation. It enhances the perception of
the interventional situation and provides means of three-dimensional catheter pose documentation. In this contribution
we develop an algorithm for tracking the three-dimensional pose of electro-physiological catheters in
biplane fluoroscopy images. It is based on the B-Snake algorithm which had to be adapted to the biplane and
in particular the asynchronous image acquisition situation. A three-dimensional B-spline curve is transformed
so that its projections are consistent with the catheter path enhancing feature images, while the information
from the missing image caused by the asynchronous acquisition is interpolated from its sequence neighbours. In
order to analyse the three-dimensional precision, virtual images were created from patient data sets and threedimensional
ground truth catheter paths. The evaluation of the three-dimensional catheter pose reconstruction
by means of our algorithm on 33 of such virtual image sets indicated a mean catheter pose error of 1.26 mm and
a mean tip deviation of 3.28 mm. The tracking capability of the algorithm was evaluated on 10 patient data
sets. In 94 % of all images our algorithm followed the catheter projections.