3D orientations of catheters from single projections

Currently, interventionists guide catheters through the vasculature using fluoroscopic images. However, three-dimensional (3D) information may facilitate catheter guidance as well as decrease patient morbidity. We have developed a technique that may facilitate visualization of the catheter in 3D using a single projection image and may, thereby, simplify interventional procedures. After images are acquired, unique points along the catheter are identified in the images and their correspondences with points in a catheter model are established. After an initial positioning, the model is rotated and translated iteratively until the projections of the points in the model align optimally with their corresponding points in the image data. Once aligned, the 3D position and orientation of the catheter relative to the imaging system are calculated. Simulation studies for catheters of diameters 0.18 and 0.32 cm indicate that the accuracies of the calculated orientations and positions were approximately 3 degrees and 0.5 cm, respectively. Phantom studies indicate that the reproducibilities of the calculated orientations and positions were approximately 2 degrees and 0.3 cm, respectively, These results indicate that this technique may provide accurate 3D information for interventional procedures.