Real-time estimation system for mean glandular dose in mammography

Area of Science:

• Medical Physics
• Radiological Imaging
• Radiation Dosimetry

Background:

• Accurate estimation of mean glandular dose (MGD) is crucial for mammography quality control and patient safety.
• Existing methods for MGD calculation can be complex and time-consuming, hindering real-time application.

Purpose of the Study:

• To construct and validate a system for real-time calculation of MGD in mammography.
• To integrate this system into the Radiology Information System (RIS) network for immediate dose assessment.

Main Methods:

• Measurements of half-value layer (HVL) and exposure dose were performed using a parallel plate chamber.
• Equations were derived to determine effective energy (Eeff) from tube voltage (kV) for various anode/filter combinations (Mo/Mo, Mo/Rh, Rh/Rh).
• Exposure output (XmAs) and MGD conversion factor (DgN) were calculated based on Eeff, using established protocols.

Main Results:

• Formulas were established to calculate Eeff based on kV for different target/filter materials.
• Equations were developed to determine exposure output (XmAs) as a function of Eeff.
• The MGD conversion factor (DgN) was determined from Eeff, with specific values provided for Mo/Mo, Mo/Rh, and Rh/Rh combinations.

Conclusions:

• A comprehensive formula was presented for calculating MGD using mammography parameters: mAs, XmAs, DgN, and source-skin distance compensation factor (SSDcf).
• The derived equations and system enable real-time MGD calculation, facilitating immediate feedback and quality assurance in mammography.