Personal operator dose in invasive cardiology as a function of body height and tube angulation

Abstract

To map in an experimental setting of the local personal operator dose for 55 selected tube angulations as a function of body height above ground. On an Alderson-Rando phantom representing the patient, we performed measurements of fluoroscopy scatter radiation ( micro Sv/h) at the operator's position, for the range of 20 - 200 cm body height, for all tube angulations in 30 degrees steps from right anterior oblique (RAO) 90 degrees to left anterior oblique (LAO) 90 degrees position, and for planes angulated cranially (+) and caudally (-) by 10 degrees, 20 degrees, 30 degrees, and 40 degrees, unless rendered unfeasible by geometric circumstances. Radiation exposure to the operator is lowest between postero-anterior (PA) 0 degrees and RAO 30 degrees angulation, and continuously increases by a factor of approx. 2 towards steep RAO, and to factors of 5 - 10 towards steep LAO views. Craniocaudal angulation at 30 degrees likewise generates personal dose levels 2 - 3 times as high. For all body heights and all LAO tube angulations, the corridor between 0 degrees - 10 degrees caudal angulation generates the least personal scatter dose, likewise irrespective of body height and craniocaudal tube angulations, the corridor between 0 degrees PA - 30 degrees RAO angulation. RAO angulations, however, being inverse to the respective 90 degrees LAO angulations, are generally 4 to 5 times less radiation extensive. Peak levels of the local personal dose vary from 160 cm body height for steep cranial LAO 90 degrees /30 degrees + views (3,500 microSv/h), to 50 cm for cranial PA 0 degrees /30 degrees + (400 micro Sv/h), and to > or = 170 cm (600 micro Sv/h) and < or = 40 cm (300 microSv/h) for steep cranial RAO 90 degrees /30 degrees + views. Caudal angulations generate slightly lower doses, with peak levels at 120 cm for LAO 90 degrees /30 degrees - views (3,000 microSv/h), at 50 cm for PA 0 degrees /30 degrees - views (300 micro Sv/h), and above 170 cm (900 micro Sv/h) and below 40 cm (500 microSv/h) for steep caudal RAO 90 degrees /30 degrees - views. The present experimental study on scatter radiation to the operator, as a function of body height and tube angulation, offers a representative data tool for all interventionists for use in invasive cardiology, to confirm the radiation safety of their favored coronary views, or to encourage less radiation-intensive angulations. Moreover, it provides new knowledge about special risks for crucial body regions and enables effective radiation protection strategies.