Utilization of conventional radiography in a regional neonatal intensive care unit in Ireland

Establishing weight-based diagnostic reference levels for neonatal chest X-rays

INTRODUCTION

As weights among neonates can vary from <900 g to >2.5 kg, weight-based Diagnostic Reference Levels (DRLs) specific to the neonatal intensive care unit (NICU) are essential. Repeated radiation exposure to this sensitive patient group raises concerns regarding high cumulative radiation doses and the potential for long-term health detriment. This study aimed to establish weight-based DRLs for neonates undergoing mobile chest radiography (CXR) in the NICU.

METHODS

Neonates were classified into three discrete groups; <1000, 1000-2500 and >2500 g. Data were collected prospectively over three months; 95 DAP values were collected, and five were excluded due to poor technique, leaving 90 patients that met the inclusion criteria for mobile CXR in the NICU. Dose-area-product (DAP) in mGycm², the peak kilovoltage (kVp) and the product of tube current and exposure time (mAs) were retrieved from the Picture Archiving and Communication System (PACS). Images and radiological reports were also analysed to confirm diagnostic image quality (IQ). Local DRLs (LDRLs) were derived using the median DAP, and national DRLs were suggested using the 3rd quartile value.

RESULTS

The proposed LDRLs for neonates weighing <1000 g was 2.7 mGycm², for neonates weighing between 1000 g and 2500 g, it was 3.7 mGycm², and for neonates weighing >2500 g it was 6.6 mGycm². The radiation dose received by the 90 (100%) neonates included in the study fell below 11.4 mGycm²; of these, 82% of the DAP values fell below the study institution's existing LDRL of 7.25 mGycm².

CONCLUSION

Weight-based DRLs provide crucial information on doses to this specific radiation-sensitive group. This work recommends using weight-based categories for DRLs and serves as a benchmark for neonatal CXR standardisation and optimisation.

IMPLICATIONS FOR PRACTICE

The proposed weight-based DRLs can be adopted for neonates' locally, nationally and internationally.

Radiological Studies in Very Low Birth Weight and Extremely Low Birth Weight Neonates: 'ALARA' Revisited

BACKGROUND

Very low birth weight (VLBW) and extremely low birth weight (ELBW) neonates are particularly susceptible to the adverse effects of ionizing radiation. There are limited data on radiographic practice among this population in resource-limited environments.

AIM

To estimate cumulative effective dose (ED) from diagnostic imaging in VLBW (1000-1500 g) and ELBW (<1000 g) neonates in a resource-limited setting.

METHOD

A retrospective analysis of all diagnostic imaging examinations performed on ELBW and VLBW neonates born in a large South African public-sector tertiary-level hospital from January through June 2015. Data were stratified by birth weight and imaging examination. The ED was estimated according to the method of Puch-Kapst. Non-parametric t-tests compared the number of radiographs and ED in VLBW and ELBW neonates, at 5% significance.

RESULTS

Three hundred and ninety-three neonates with median birth weight 1130 (IQR: 930-1340) g were included; 265 (67%) were VLBW and 128 (33%) ELBW; 48 (12%) died at a median of 7 (IQR: 2-17) days. A median of 2 (IQR: 1-5) radiographs were performed per neonate, with median ED 28.8 (IQR: 14.4-90.8) μSv. The median radiographic exposures for VLBW and ELBW neonates were 1 (IQR: 1-4) and 4 (IQR: 2-9), respectively, (p < 0.0001) with median ED 14.4 (IQR: 14.4-70.4) μSv and 71.2 (IQR: 28.8-169.3) μSv, respectively, (p < 0.0001). Radiographic exposure for VLBW neonates was lower than previously documented for this population.

CONCLUSION

Neonatal radiographic practice in resource-limited settings has the potential to contribute to the discourse on international best practice.