Can placing lead-rubber inferolateral to the light beam diaphragm limit ionising radiation to multiple radiosensitive...

This article investigates a practical method of reducing the impact of scattered radiation during a lateral radiographic projection of the elbow. The light beam diaphragm (LBD) is generally accepted to limit ionising radiation using horizontal and longitudinal lead shutters, yet this article evidences further dose limitation by placing lead-rubber inferolateral to the LBD device.

Using an anthropomorphic phantom and arm construction scattered radiation was recorded at multiple radiosensitive organs. A 15 cc ionisation chamber (model 10100 AT TRIAD) was placed on each radiosensitive organ (eye, thyroid, breast, testes, spleen and ovaries) measuring exposure rate (μGy/s). Dose readings were recorded before and after the placement of lead-rubber inferolateral to the LBD. A paired two sample t-test was undertaken affirming how likely dose limitation was attributable to chance (p < 0.05).

Descriptive and inferential statistics demonstrate dose reduction to radiosensitive organs (right eye 53%, right breast 53%, left eye 39%, thyroid 13%, left ovary 9%, testes 6%, left breast 3% and spleen 2%) upon placement of the lead-rubber inferolateral to the LBD. The paired two sample t-test demonstrated statistically significant dose limitation (t = 2.04, df = 7, p = 0.04) thus significant for radiographic practice.

Placement of lead-rubber inferolateral to the LBD limits dose to multiple radiosensitive organs. Right (53%) and left (39%) eye lens, right breast (53%), thyroid (13%), left ovary (9%), testes (6%), left breast (3%) and spleen (2%) statistically demonstrate dose limiting opportunities to patients.