Impact of increasing tube potential and additional filtration on image quality and radiation dose for digital chest radiography
Authors:   Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phisanulok Province, Thailand., Pengpan Thanyawee , Chandai Phusapong ,   Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phisanulok Province, 65000 Thailand, Tiansawang Pichapuk ,   Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phisanulok Province, 65000 Thailand, Yasamut Karnsinee ,   Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phisanulok Province, 65000 Thailand, Rattanarungruangchai Natch ,   Department of Radiation Dose Measurement and Assessment, Nuclear Technology Service Center, Thailand Institute of Nuclear Technology (Public Organization), Nakornnayok province, Thailand., Prapan Ausanai ,   Department of Radiological Technology, Faculty of Allied Health Sciences, Naresuan University, Phisanulok Province, Thailand.
Published: January 2025

Background: Chest radiography is one of the most commonly performed examinations as routine check-ups in radiology departments. Radiographers should be concerned with minimizing patient radiation dose while maintaining high diagnostic image quality.

Objective: This study aimed to investigate the effect of increasing tube potential (kV) and adding filtration on image quality and radiation dose for posteroanterior (PA) chest radiography using a digital radiography (DR) system.

Materials and methods: Eighty-five kV with no filter was used as the reference exposure technique. Subsequently, the kV was increased to 96, 117, and 133, and additional filtrations of 2 mm Al, 1 mm Al+0.1 mm Cu, and 1 mm Al+0.2 mm Cu were applied. A total of sixteen images were produced. The entrance surface air kerma (ESAK) was measured and evaluated. Signal-to-noise ratio (SNR) and contrastto-noise ratio (CNR) were accessed for objective image quality. Five independent radiographers assessed a subjective image quality (IQ) score using two alternative forced choices (2AFC).

Results: Increasing kV and adding filtration reduced the ESAK while enhancing the SNR and CNR. However, the IQ score declined relative to the reference image when higher kV and additional filtration were applied except 85 kV. The IQ score indicated that an image acquired at 85 kV with 1 mm Al+0.2 mm Cu showed superior quality compared to the reference image. Notably, the SNR for this image was significantly higher (p<0.05). Additionally, this image resulted in a lower radiation dose (13.44 mGy) compared to the reference image (24.97 mGy). Furthermore, the image quality (IQ) score was higher than the reference images.><0.05). Additionally, this image resulted in a lower radiation dose (13.44 mGy) compared to the reference image (24.97 mGy). Furthermore, the image quality (IQ) score was higher than the reference images.

Conclusion: This study’s findings indicate that using an 85 kV with 1 mm Al+0.2 mm Cu additional filtration for digital PA chest radiography can reduce the radiation dose while improving image quality. However, this study used an anthropomorphic chest phantom; further clinical research is recommended.