Doses during chest examinations at the neonatal and paediatric intensive care unit (NPICU) of a general hospital in Malta.

Abstract

Objectives The objectives of the study were to measure kerma area product (KAP) values during portable chest x-rays on neonatal and paediatric patients aged 0 to 12 months, nursed at the neonatal and paediatric intensive care unit (NPICU) of a local general hospital, calculate corresponding entrance surface dose (ESD), compare mean values with those found in the European literature and suggest local diagnostic reference levels (LDRL) for the hospital concerned. Research Design KAP and ESD from portable chest x-rays on neonatal and paediatric patients aged 0 to 12 months nursed at the neonatal and paediatric intensive care unit (NPICU) of the hospital concerned were surveyed. As no national DRLs are available mean KAP and ESD values were set as LDRLs. Different LDRLs were also set for different thicknesses of paediatric patients as recommended in the literature. Results The main results from the study were: (a) Mean doses for AP chest of neonatal and paediatric patients aged 0 to 12 months in the hospital concerned are well below those found in the European literature reflecting the modem devices available in the hospital and showing that the radiographers are properly trained and making good use of digital imaging. (b) The LDRL in terms of KAP derived from the total sample was 4100 +/- 300μ.Gycm2 whilst that in terms of ESD was 26 +I-1 μGy. LDRLs for the various different patient thickness groups were 1800 +/-140 μGycm2 and 23 +/-1 μGy for a patient thickness of 5.0-6.9cm, 3900 +/-280 μGycm2 and 24 +/- 1 μGy for a patient thickness of 7.0- 8.9cm, 5100 +/- 440 μGycm2 and 29 +/- 2 μGy for a patient thickness of 9.0-11.0cm. (c) Further lowering of the LDRLs was found to be possible if well collimated images only were considered Conclusions On the basis of the study, the researcher concluded that even though patient dose values in this study are well below those found in the European literature further reduced values of the LDRL can be obtained by improving collimation. It is suggested that the use of a higher kV I reduced mAs, using higher sensitivity FUJI STBD IP cassettes (which are available at the hospital concerned) and appropriate additional filtration and specifically designed paediatric AEDs can reduce dose even further.