Force balancing in mammographic compression.

Area of Science:

• Medical Imaging Physics
• Radiologic Technology
• Biomechanical Engineering

Background:

• Mammography image receptor height adjustment is critical before breast compression.
• Inadequate height settings can cause force imbalances between the image receptor and compression paddle.
• This imbalance leads to tissue stretching, increased patient discomfort, and potential image quality degradation.

Purpose of the Study:

• To implement and assess a method for measuring and minimizing image receptor height-induced force imbalance.
• To evaluate the feasibility of this method as an objective and reproducible technique for setting image receptor height.
• To improve mammography procedures by reducing patient pain and optimizing image quality.

Main Methods:

• A silicone breast phantom underwent 13 craniocaudal compressions with varied image receptor heights (12 cm range).
• Compression force was incrementally increased to 140 N, measuring forces from the paddle, image receptor, and patient support.
• Trials were repeated eight times with phantom repositioning to ensure reproducibility.

Main Results:

• A unique image receptor height was identified for each paddle force, achieving force balance on the breast phantom.
• Deviations from the optimal height increased force imbalance significantly (e.g., 9.4 ± 1.9 N/cm at 140 N).
• Force imbalance can be determined by monitoring patient weight changes during compression, even without direct image receptor force measurement.

Conclusions:

• Minor adjustments in image receptor height during mammography can cause substantial force imbalances.
• Such imbalances increase pain and can compromise image quality and radiation dose efficiency.
• Monitoring and actively adjusting image receptor position during compression can mitigate these negative effects.