Comparing 10 kVp and 15% Rules in Extremity Radiography

Area of Science:

• Radiological physics
• Medical imaging technology

Background:

• Current radiography protocols often use the 15% rule for technique adjustments.
• There is a need for simpler methods to reduce patient radiation dose while maintaining diagnostic image quality.

Purpose of the Study:

• To evaluate the 10 kVp rule as a potential substitute for the 15% rule in extremity radiography.
• To assess the impact on diagnostic image quality and patient radiation dose.

Main Methods:

• Exposures were performed on anthropomorphic phantom extremities (hand, knee, shoulder) using a digital radiography system.
• Thermoluminescent dosimeters (TLDs) measured entrance skin dose.
• Image quality was assessed using detector exposure indicators.

Main Results:

• Both the 10 kVp and 15% rules maintained optimal detector exposure indicators.
• Entrance skin dose was lower with both rules compared to system-preset techniques, particularly for the 10 kVp rule in hand and shoulder imaging.
• No significant failures were observed for either rule.

Conclusions:

• The 10 kVp rule is a viable alternative to the 15% rule for extremity radiography.
• This substitution can simplify technologist calculations, reduce radiation dose, and maintain diagnostic image quality.
• Further research with varied equipment and examinations is recommended.