Over Time RF Fitting for Jitter Free 3D Vertebra Reconstruction from Video Fluoroscopy

Abstract

Over the past decades, there has been an increasing interest in spine kinematics and various approaches have been proposed on how to analyse spine kinematics. Amongst all, emphasis has been given to both the shape of the individual vertebrae as well as the overall spine curvature as a mean of providing accurate and valid spinal condition diagnosis. Traditional invasive methods cannot accurately delineate the intersegmental motion of the spine vertebrae. On the contrary, capturing and measuring spinal motion via the non-invasive fluoroscopy has been a popular technique choice because of its low incurred patient radiation exposure nature. In general, image-based 3D reconstruction methods focus on static spine instances. However, even the ones analysing sequences yield in unstable and jittery animations of the reconstructed spine. In this paper, we address this issue using a novel approach to robustly reconstruct and rigidly derive a shape with no inter-frame variations. This is to produce animations that are jitter free across our sequence based on fluoroscopy video. Our main contributions are 1) retaining the shape of the solid vertebrae across the frame range, 2) helping towards a more accurate image segmentation even when there's a limited training set. We show our pipeline's success by reconstructing and comparing 3D animations of the lumbar spine from a corresponding fluoroscopic video.