Vertebrae Tracking in Lumbar Spinal Video-Fluoroscopy Using Particle Filters with Semi-automatic Initialisation

Vertebrae tracking in lumbar spinal video-fluoroscopy is the first step in the analysis of vertebrae kinematic in patients with lower back pain. This paper presents a technique to track the vertebrae using particle filters with image gradient based likelihood measurement. In the first X-ray frame, the vertebrae are semi-automatically segmented and a bi-spline curve is fitted to the landmark points to construct the vertebrae outlines; then a particle filter is used to track the vertebrae through the sequence. The proposed technique is able to track the vertebrae in both lateral and frontal video-fluoroscopy sequences. The tracking results compare well with the ground truth data obtained by manually segmenting the vertebrae.