The influence of 10 kVp and 15% rule applications on patient dose and image quality in extremities radiography: A phantom study
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Abstract
Background: Optimizing image quality and radiation dose is crucial in general radiography, adhering to the As Low As Reasonably Achievable (ALARA) principle.
Objective: This study aimed to evaluate the impact of applying the 10 kVp and 15% rules on image quality and patient dose in extremity X-ray imaging using both computed radiography (CR) and digital radiography (DR) systems.
Materials and methods: X-ray imaging of hand, elbow, knee, and foot phantoms was performed using three different exposure techniques on both CR and DR systems. These techniques included the standard technique (ST) based on the established guidelines of the imaging systems, increased 10 kVp with a 50% mAs reduction from ST (10 kVp rule), and increased 15% kVp with a 50% mAs reduction from ST (15% rule). The entrance skin dose (ESD) was measured using nanoDot™placed on the phantom’s surface. The physical image qualities in contrast-to-noise ratio (CNR) and figure of merit (FOM) were utilized to assess the balance between image quality and radiation doses.
Results: The ESD was reduced by an average of -16% and -25% when applying the 10 kVp and 15% rules for all extremity imaging. This reduction decreased image CNR by -18% and -12%, respectively. There was no significant difference in CNR between the 15% and 10 kVp rule techniques for all extremity examinations in both CR and DR systems (p>0.05). Meanwhile, the exposure and deviation indexes remained within the established guidelines for CR and DR systems. However, the FOM values tended to be greater with the 15% rule technique than other techniques.
Conclusion: The ESD reduction was observed when applying the 10 kVp and 15% rules for all extremity imaging, both in CR and DR systems, with a slight degradation in image quality. The 15% rule represents the best option for optimization of image quality and patient dose based on the FOM results.
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Personal views expressed by the contributors in their articles are not necessarily those of the Journal of Associated Medical Sciences, Faculty of Associated Medical Sciences, Chiang Mai University.
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