The EOS System: Overall Assessment of Balance of the Vertebral Column and Its Movements

Abstract

The EOS imaging system was designed by the common work of physics scientists, biomechanical engineers radiologists and orthopaedists. The result is a device demonstrating anterior-posterior and lateral view radiographs of the entire body, in a standing or sitting position without any distortion, and with a low dose of radiation allowing study of the alignment of the spinal skeleton in a functional posture including the consequences of gravity. From these data, a proper computer software obtains a 3D surface reconstruction of the entire skeleton. This explains the importance of this device to study pathologies of the spine whatever age (the only requirement is sufficient stillness of the patient during scanning). Thanks to the reliability of the reconstruction the interest is considerable and can replace the 3D reconstructions from CT scanning with much less radiation dose (around 1000 times less, particularly important when used in children, adolescents or young adults). Applications extend from early detection, evaluation of any spinal deformities as well as the thoracic cage, planning for treatment, post op evaluation,… For cervical spine dynamic studies can be evaluated for example in flexion/extension. When matched with external 3D surface recording of the motion of the body, the approach of the real balance of the human body is achieved with its therapeutic consequences.