3D trajectory assessment of an IVUS transducer from single-plane cineangiograms: a phantom study

The recovery of the 3D path of the transducer used during an intravascular ultrasound (IVUS) examination is of primary importance to assess the exact 3D shape of the vessel under study. Traditionally, the reconstruction is done simply by stacking the images during the pullback, or more recently using biplane angiography to recover the vessel curvature. In this paper, we apply the formulation of a perspective projection model, which enables us to determine the angulations of an IVUS transducer from single-plane angiogram only. The transducer angulation reconstruction is based on the foreshortening effect as seen from the X-ray images. By comparing the measured to the true transducer length, we are able to get its incidence angle. The transducer trajectory is reconstructed by stitching together the different estimated angulations obtained from each image in a cineangiogram sequence. The method is described and validated on a helical vessel phantom.