Improving the accuracy of digital CT pelvimetry

Digital pelvimetry is performed to assess the feasibility of vaginal breech delivery. This provides measurements of the anteroposterior inlet, transverse inlet, and interspinous distance. The transverse inlet measurement determined from an anteroposterior ScoutView can be inaccurate if its level is not at the gantry isocenter. Using a simple geometric argument, the theoretical error of this measurement is calculated and a method provided to allow for correction of this error.