Scatter dose calculation for anti-scatter linear grids in mammography

Area of Science:

• Medical Physics
• Radiological Imaging
• Biomedical Engineering

Background:

• Scatter radiation in mammography degrades image quality by reducing contrast.
• Anti-scatter grids are crucial for minimizing scatter radiation during mammographic imaging.
• Optimizing grid geometry is essential for enhancing diagnostic accuracy in mammography.

Purpose of the Study:

• To optimize the geometry of a mammography anti-scatter linear grid.
• To achieve the minimum scatter-to-primary ratio (SPR) across a range of X-ray tube voltages.
• To identify a single optimal grid design suitable for diverse breast phantom thicknesses.

Main Methods:

• Utilized Monte Carlo simulations to model and optimize grid parameters.
• Evaluated grid performance for breast phantom thicknesses ranging from 30 to 80 mm.
• Focused on optimizing septa height, septa thickness, and interspace thickness.

Main Results:

• A single optimal grid design was identified with specific dimensions (0.9mm septa height, 12µm septa thickness, 100µm interspace thickness).
• This optimal grid achieved a scatter-to-primary ratio (SPR) between 0.153 and 0.330.
• The grid demonstrated a Bucky factor (BF) below 2.5 and a contrast improvement factor (CIF) of 1.3.

Conclusions:

• The optimized mammography anti-scatter grid design effectively reduces scatter radiation.
• The proposed grid geometry provides a favorable balance between scatter reduction and image quality enhancement.
• This optimized grid design is suitable for a wide range of breast phantom thicknesses, enhancing mammographic imaging performance.