High KV technique helps reduce radiation dose in neonates undergoing chest radiography

UAE: The high kilovoltage technique can play a critical role in reducing radiation dose for neonates undergoing chest radiography without compromising image quality, states an article published in Radiation Physics and Chemistry.

Chest radiography is an essential and most often utilized radiological modality in the neonatal intensive care unit. To minimize radiation exposure in this susceptible population, it is important to monitor image optimization. Neonates are at higher risk of cancer than adults as they are more radiosensitive and have a longer life expectancy. Therefore, it is essential to protect neonates from radiation hazards.

The focus should be to ensure a minimum radiation dose required to maintain image quality for accurate diagnosis. It can be done by adjusting the voltage in the machine's x-ray tubes (kVp) and the time used to acquire quality images, as measured in milliampere seconds (mAs). Increasing voltage can lower mAs but also reduces image quality. Current guidelines recommend between 60-80 kVp and between 1-2 mAs for pediatric patients undergoing anteroposterior (AP) chest x-rays. No specific recommendations have been developed for neonates.

W.Elshami, University of Sharjah, UAE, and colleagues conducted a study to evaluate the effectiveness of the high HKVp technique on reducing radiation dose to neonates undergoing Antero-posterior (AP) chest x-rays.

Investigators used a newborn anthropomorphic phantom to simulate a neonate for the study. Different combinations of KVp and mAs were used to acquire chest x-ray images. Dose area product (DAP) was recorded in the Digital Imaging and Communications in Medicine (DICOM) header. The effective dose was determined using Monte Carlo simulation. Subjective assessment of image quality was evaluated by three radiologists blindly and the Objective assessment was done using the calculation of the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR).

Key findings of the study,

• The reduction in the DAP and effective dose at 50 KVp was 26.7% and 19.2%, respectively and for 60 KVp it was 22.9% and 20.2%, respectively. The same at 70 KVp was 40% and 26%, respectively.

• There were no significant differences in the means of the DAP, SNR, CNR, and effective dose among different combinations of KVp and mAs.

The authors conclude that the optimization of kVp and mAs has a significant effect on reducing patient radiation dose, thus in neonates undergoing chest x-rays, the use of high KVp will help reduce radiation dose considerably while maintaining image quality.

Even though the present study was an experiment using a phantom (which limited image evaluation), it highlights the need for analyzing neonate patient images and calculating risks from different exposures to ensure safe practice, the authors wrote.

Reference:

W. Elshami, M.M. Abuzaid, M.M. Gibril, A. Sulieman, D.A. Bradley,  Impact of high kilo-voltage peak technique on radiation dose for neonates undergoing chest radiography: Experimental study, Radiation Physics and Chemistry, Volume 199,2022,110327,ISSN 0969-806X, https://doi.org/10.1016/j.radphyschem.2022.110327.