3D reconstruction of spine from partial biplanar radiographic image data

Three-dimensional reconstruction of the human spine is very much essential in diagnosis, planning of surgery and treatment of several spinal deformities. This can be achieved using stereo-radiographic reconstruction technique that uses postereo-anterior (PA) and lateral (LAT) radiographs. Here, an uncalibrated approach is proposed in which a generic spine model is deformed according to the partial data available in these radiographs. The angle at which each vertebra oriented is automatically extracted from the biplanar radiographs. The generic model is first aligned along the spine midline and each vertebra is rotated according to the angles obtained from the PA and LAT radiographs. The projection of this 3D model is taken in frontal and lateral planes and orientation of each vertebra is compared with that of the radiographs. The difference between the angles is minimized by suitable vertebral rotations until it becomes negligible. The model is validated by comparing angle measurements and back projection of the 3D model onto the radiographs. The result obtained is superior by the fact that radiographs are uncalibrated and has minimum human intervention. The model gives a better visualization of the -deformity of the human spine without involving specialized equipment.