Quantifying radiation exposure in the radiological investigation of non-arthritic hip pain

Abstract

Radiological investigations are essential for evaluating underlying structural abnormalities in patients presenting with non-arthritic hip pain. The aim of this study is to quantify the radiation exposure associated with common radiological investigations performed in assessing patients presenting with non-arthritic hip pain. A retrospective review of our institutional imaging database was performed. Data were obtained for antero-posterior, cross-table lateral, frog lateral radiographs and low-dose CT hip protocol. The radiation dose of each imaging technique was measured in terms of dose-area product with units of mGy cm2, and the effective doses (ED, mSv) calculated. The effective radiation dose for each individual hip radiograph performed was in the range of 0.03–0.83 mSv [mean dose-area product 126.7–156.2 mGy cm2]. The mean ED associated with the low-dose CT hip protocol (including assessment of femoral anteversion and tibial torsion) was 3.04 mSv (416.8 mGy cm2). The radiation dose associated with the use of CT imaging was significantly greater than plain radiographs (P < 0.005). Investigation of non-arthritic hip pain can lead to significant ionizing radiation exposure for patients. In our institution, the routine protocol is to obtain an antero-posterior pelvic radiograph and then a specific hip sequence Magnetic Resonance Imaging (MRI) scan which includes the assessment of femoral anteversion. This provides the necessary information in the majority of cases, with CT scanning reserved for more complex cases where we feel there is a specific indication. We would encourage the hip preservation community to carefully consider and review the use of ionizing radiation investigations.