Cone Beam CT (CBCT) imaging is increasingly finding applications within the radiology environment e.g. interventional radiology, cardiology and for some surgical applications. The Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER17) require every exposure to ionising radiation to have a net benefit and that consideration is given to alternative techniques which have the same objective but involve less or no radiation exposure (regulation 11). Additionally IRMER17 requires all exposures to be optimised to ensure that doses are kept as low as reasonably practicable consistent with the intended purpose (regulation 12). To comply with the requirements of IRMER 2017 the radiation dose from the procedure needs to be evaluated. For diagnostic radiology radiation effective doses are determined either using simulation or applying suitable conversion factors to convert a measured dose to effective dose. Currently these factors are not available for CBCT imaging. This research project will produce conversion factors to allow the dose metrics displayed on the radiology equipment to be converted to an effective dose.