Technical error of vertebral rotation measurement directly on the computer screen, according to Raimondi method

Background The measurement of vertebral axial rotation according to Perdriolle and to Raimondi is reliable on standard films, where apical vertebrae show a proper size for the scale of both systems. Current digital radiographs are delivered on a CD format (screen) or on a film format, usually with a non proper size for the two above mentioned methods. No system has been described for a rapid assessment of vertebral rotation directly from the screen. Raimondi system, with no needs for reference marks, could be considered a proper tool to be use for that purpose. The size of the apical vertebra can be increased as much as necessary when using CD format as well as digital photography. However this could be considered, together with other factors, a source of error.