Abstract 16093: New Method Precisely Registers Cardiac Resynchronization Left Ventricular Lead Position from Standard Two-Dimensional Fluoroscopic Projections on Three-Dimensional Cardiac Magnetic Resonance Images
Background: The relationship between cardiac resynchronization therapy (CRT) LV lead location and scar or regional mechanical function from pre-CRT cardiac imaging likely has an important impact on CRT response. To better define this relationship and test hypotheses regarding optimal LV lead position, precise methodology is needed to register the post-CRT LV lead position on the pre-CRT imaging study.
Methods: Three reference landmarks (right ventricular apex, coronary sinus os, lateral mitral annulus) were identified on both cardiac magnetic resonance (CMR) images and standard left anterior and right anterior oblique 2-D fluoroscopic projections in order to project the post-CRT LV lead location onto the pre-CRT CMR study. Calibration with a phantom enabled transformation of points selected in standard 2-D fluoroscopic views into 3-D space. We identified the projected 3-D CMR LV lead location as the point on the CMR LV epicardial contour with lead-landmark distances in 3-D CMR coordinates most similar to those measured by fluoroscopy. After validation in a canine model, the predicted CMR LV lead location was measured and compared to gold-standard data in four patients receiving CRT.
Results: The accuracy of the predicted LV location in the initial canine validation was within 9 mm. In patients, the LV lead location was mid-apical-posterolateral (n=2), mid-posterolateral (n=1), or basal anterior (n=1). Lead-landmark distance accuracy was 12.3 ± 8.2mm in all patients. Lead position accuracy was 17.1 ± 2.2mm in 3 patients with post-CRT CT scans (Figure). The accuracy in the fourth patient with pre-CRT MR CS venography was within 8 mm of the most distal point in that branch seen by CMR.
Conclusions: This robust methodology provides accurate registration of post-CRT LV lead position into pre-CRT CMR or CT studies and enables quantitative optimization of LV lead location relative to scar and regional function. .
- © 2012 by American Heart Association, Inc.