PA positioning significantly reduces testicular dose during sacroiliac joint radiography

Radiation dose to the testes in the antero-posterior (AP) and postero-anterior (PA) projection of the sacroiliac joint (SIJ) was measured with and without a scrotal shield. Entrance surface dose, the dose received by the testicles and the dose area product (DAP) was used.DAP measurements revealed the dose received by the phantom in the PA position is 12.6% lower than the AP (p≤ 0.009) with no statistically significant reduction in image quality (p≤ 0.483). The dose received by the testes in the PA projection in SIJ imaging is 93.1% lower than the AP projection when not using protection (p≤ 0.020) and 94.9% lower with protection (p≤ 0.019). The dose received by the testicles was not changed by the use of a scrotal shield in the AP position (p≤ 0.559); but was lowered by its use in the PA (p≤ 0.058). Use of the PA projection in SIJ imaging significantly lowers, the dose received by the testes compared to the AP projection without significant loss of image quality.