EOS is a newly-designed imaging system that allows to study spine and lower limbs in standing position (in loaded condition). Through ionizing radiation, EOS obtains digital images that are apparently similar to those of a conventional X-ray machine, yet with a sharply reduced X-ray exposure dose, and susceptible to 3D reconstruction. 

Although EOS can provide images of multiple anatomical areas, it was actually designed to study, jointly or separately, the spine, the pelvic girdle and lower limbs "under loaded conditions" in a standing or sitting patient with only one image obtained through a few seconds of exposure. Despite their apparent similarity, EOS diagnostic images cannot be obtained through conventional imaging systems as they are not subjected to enlargement and photographic distortion; also, EOS imager allows for comprehensive assessment of the entire axial skeleton thanks to a 175 cm field of vision in 1:1 scale, with a dose that is noticeably smaller (8 to 10 times) than the one delivered by conventional imaging systems and not comparable to that of a CT scan (delivered dose is 800/900 times smaller).