Figure 1: Study design with phantoms for measurements of radiation in two different settings. Setting A: The CTDI measuring chamber was placed inside the wrist phantom for measurement of the radiation exposure due to the primary beam and the Victoreen 20 cm above the wrist phantom (where the head would be in a clinical situation) for measurement of the scatter to the head. Setting B: The CTDI measuring chamber was placed inside the wrist phantom for measurement of the radiation exposure due to the primary beam and the Victoreen dosemeter above the head phantom for measurement of the scatter to the rest of the body.