SIMULATING LOCAL DENSE AREAS USING PMMA TO ASSESS AUTOMATIC EXPOSURE CONTROL IN DIGITAL MAMMOGRAPHY

Area of Science:

• Medical Imaging
• Radiology
• Biomedical Engineering

Background:

• Digital mammography (DM) utilizes automatic exposure control (AEC) for optimizing X-ray exposure based on breast density.
• European guidelines recommend phantom-based testing to assess AEC performance, specifically for local dense areas and signal-to-noise ratio (SNR).

Purpose of the Study:

• To evaluate a proposed phantom-based test for its effectiveness in assessing AEC performance in DM systems.
• To analyze the test's impact on SNR and radiation dose across different breast compositions.

Main Methods:

• Four digital mammography systems were tested using the proposed phantom.
• Analytic calculations were performed to determine the glandular fraction simulated by the local dense area.
• Signal-to-noise ratio (SNR) and radiation dose were measured for each system.

Main Results:

• The phantom test effectively simulates a range of breast compositions, from adipose to fully glandular.
• The radiation doses measured with the phantoms closely align with typical patient dose distributions.
• The test demonstrated its capability to evaluate AEC performance regarding both SNR and dose.

Conclusions:

• The proposed phantom test, with minor modifications, is a valuable tool for assessing AEC performance in digital mammography.
• This evaluation method contributes to quality assurance in breast cancer screening by ensuring accurate exposure control.
• The test provides a reliable means to verify both image quality (SNR) and patient safety (dose).