EOS system

The EOS System is shown in Figure 1 and its geometry depicted in Figure 2. Each X‐ray tube/detector combination moves vertically at different lengths, as adjusted for each study by the operator, to obtain frontal/anteroposterior (AP) and lateral (LAT) images simultaneously. The distance by which the tube travels vertically during image acquisition for each study will henceforth be referred to as study length.

EOS System (EOS imaging, France) installed in our hospital. Patients step onto the central platform of the system where they stand whilst the image is acquired.

Geometry of the EOS System (view from above) indicating the Source to Image Distances (SID) for each X‐ray tube/detector combination (frontal and lateral). The patient stands in the middle of the central platform of the system. The distance between each X‐ray tube and the EOS system covers nearest to the tube is indicated in blue.

The X‐ray sources of the unit consist of two fan‐shaped X‐ray beams collimated to 0.5 mm width. The beams are positioned at 90° to each other and coupled to linear detectors with 0.5 mm‐thick aluminium collimators, to prevent scattered radiation from detection.

The detector design is based on a gaseous X‐ray detector with a proportional multi‐wire chamber. 7