Figure 1

This is an example of "adaptive" projection navigation. Two dimensional slices are volume-rendered to show their three-dimensional position. In addition, the active catheter device is shown in superimposed projection-mode. The viewing angle of the two-dimensional slices can interactively be changed [A-C], but in this mode the projection angle is always perpendicular to the selected viewing angle. In this example, an active myocardial injection catheter is navigated toward an infarct border. The catheter contains two receiver coils: a small coil at the tip (red) and a loopless antenna along the shaft (green). A yellow dot is applied by the operator to mark the tissue target. The volume rendering is rotated manually during the procedure to view the device trajectory from different angles, conveying three-dimensional information [14]. In A and B, the catheter tip is outside the imaging plane; in C the catheter tip is in-plane and coincides with the selected target.