Organ dosimetry in spinal radiography: a comparison of 3-region sectional and full-spine techniques

It is important that absorbed and effective doses of radiation to patients from diagnostic plain film radiography be optimised, however whether 3-region sectional or full-spine radiography delivers the lowest patient radiation dose remains controversial. This study investigated and quantified the difference in both full-body effective doses and absorbed doses to critical organs resulting from sectional and full-spine imaging protocols. Lithium fluoride (LiF) thermoluminescent dosimeters (TLD-100) were positioned within an anthropomorphic phantom at the levels of eye, thyroid gland, breast, ovary and testis. The anteroposterior (AP) sectional and AP full-spine exposures employed gonadal shielding, and the AP and lateral full-spine exposures utilised Nolan density-equalising filtering procedures. When compared with AP sectional exposures, the AP full-spine exposure gave consistently less absorbed doses to all critical organs, most noticeably at the thyroid gland. Lateral exposures gave varying results, with the full-spine exposures giving larger radiation doses to breasts and testes and the sectional exposures resulting in larger doses to the thyroid gland and ovaries. Further comparison shoed the full-spine protocol (AP and lateral) to give a lower calculated total-body effective dose than the 3-region sectional protocol (AP and lateral). Concerns over high radiation doses resulting from diagnostic spinal radiography, especially those relating to use of full-spine imaging protocols, were not supported by our data. Consequently, clinical use of full-spine radiographic techniques should not be limited on the basis o radiation absorbed dose.