Gonad dose in AP pelvis radiography: Impact of anode heel orientation

Abstract

Purpose: For antero posterior (AP) pelvis radiographic examination, determine the impact of anode heel orientation on female/male gonad dose.

Methods: High sensitivity thermo-luminescent dosimeters (TLDs) were used with an ATOM dosimetry phantom; the phantom was positioned for AP pelvis. TLDs were placed into the testes and ovaries. Radiation dose received by these organs was measured with the feet toward anode and feet toward the cathode. kVp, mAs and SID were manipulated to generate a range of exposures. A dose profile was also generated using Unfors Mult-O-Meter 401 along the long axis of the phantom.

Results: A decrease in dose from the central ray toward the anode was noted, with a marked increase toward the cathode. A significant reduction in dose was received by the testes with feet towards the anode compared with feet towards cathode (P˂0.001). No difference was seen for ovarian dose (P˃0.05). kVp, mAs and SID all have an effect on male and female gonad dose.

Conclusion: For male pelvis imaging, placing feet towards the anode can be used as a simple dose reduction method.

Keywords: Gonad dose; Patient dosimetry; X-ray imaging.