Radiation dose quantities and risk in neonates in a special care baby unit

Abstract

Radiographs are taken in the neonatal period most commonly to assist in the diagnosis and management of respiratory difficulties. Frequent accurate radiographic assessment is required and a knowledge of the radiation dose is necessary to justify such exposures. A survey of radiation doses to neonates from diagnostic radiography (chest and abdomen) has been carried out in the special care baby unit of the Royal Free Hospital. Entrance surface dose (ESD) was calculated from quality control measurements on the X-ray unit itself. Direct measurement of radiation doses was also performed using highly sensitive thermoluminescent dosemeters (TLDs) (LiF:Mg,Cu,P), calibrated and tested for consistency in sensitivity. ESD, as calculated from exposure parameters, was found to range from 28 microGy to 58 microGy, with a mean ESD per radiograph of 36+/-6 microGy averaged over 95 examinations. ESDs as derived from TLD crystals ranged from 18 microGy to 58 microGy for 30 radiographic examinations. The mean energy imparted, the mean whole body dose per radiograph and the mean effective dose were estimated to be 14+/-8 microJ, 10+/-4 microGy and 8+/-2 microSv, respectively. Assuming that neonates and fetuses are equally susceptible to carcinogenic effects of radiation, which involve an overestimation of risk, the radiation risk of childhood cancer from a single radiograph was estimated to be of the order (0.3-1.3) x 10(-6). Radiation doses compared favourably with the reference values of 80 microGy ESD published by the Commission of the European Communities in 1996, and 50 microGy published by the National Radiological Protection Board in 2000.

Riscos dos exames radiográficos em recém-nascidos internados em um hospital público de Belo Horizonte, MG

“…The present study Chapple et al (6) Wraith et al Armpilia et al (19) Brindhaban e Al-Khalifah have shown that the equipment time and voltage accuracy and reproducibility are in compliance with the technical performance standards established by the Brazilian authorities (23) . However, the half-value layer at 80 kV (1.75 mm of Al) was significantly below of the minimum value established by the mentioned technical standard (2.3 mm of Al); that is to say, the x-ray tube output is low, even with the utilization of inadequate filtration.…”

“…This is a function of the field size, equipment filtration and radiographic technique employed. A fixed value of 1.16 for BSF was adopted in the present study (19) .…”

Radiation doses and risks to neonates undergoing radiographic examinations in intensive care units in Tunisia

“…The International Commission on Radiological Protection (ICRP) has both encouraged "authorized bodies" to set diagnostic reference levels (DRLs) as dose optimization tools 4 , consistent with regional, national or local area to which they apply and also defined the concept of effective dose (E) 4 , which has become an accepted method for estimating dose and associated risks in diagnostic radiology. Some studies have been interested to dose index, like entrance surface dose (ESD) or dose area products (DAP) measurements [5][6][7][8][9][10] , but only few ones addressed to effective dose (E) comparison, for newborns and especially preterm infants [9][10][11] . However, in Tunisia, the contribution of these examinations to the patient's exposure is still largely unknown.…”

Neonatal chest radiography - Comparing image quality and dose for contact-techniques vs. under-tray techniques

“…Special attention should be given to neonatal imaging since doses during childhood results in increased risk of cancers. Therefore it is important to ensure that radiation doses from radiographic examinations are to be kept to the minimum whilst maintaining the quality of radiographic images (Armpilia, 2002).…”

“…Lower noise level results in better radiographic image because it improves contrast resolution, but normally at the cost of a higher patient dose. (Armpilia, 2002) Our aim is to use the X-ray beam efficiently, producing the best possible image with good resolution and low noise with a dose reasonable to the patient. The balance between patient dose and noise is the most challenging task in optimisation.…”