A novel breast software phantom for biomechanical modeling of elastography

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Computational Mechanics

Background:

• Physical phantoms are essential for testing breast imaging technologies but lack flexibility in size, shape, and composition.
• Software breast phantoms offer a modifiable alternative for applications like image fusion and biomechanical modeling.

Purpose of the Study:

• To develop a 3D software breast phantom using a mechanical design tool for investigating the biomechanics of elastography via finite element modeling (FEM).
• To propose this phantom as an intermediate assessment tool for elastography simulation, bridging the gap between common phantoms and clinical testing.
• To design a flexible phantom for varying breast geometry and biomechanical parameters, enhancing elastography simulation capabilities.

Main Methods:

• Developed a 3D software breast phantom using a mechanical design tool, based on normal breast anatomy illustrations, without geometric primitives or imaging data.
• Demonstrated elastography simulation by applying static stress to a simulated tumor and calculating normal strains in 3D and 2D (plane strain approximations).
• Investigated contrast transfer efficiency (CTE) through a parametric study of tumor location, shape, and stiffness, comparing results to a standard block phantom.

Main Results:

• The 3D breast phantom demonstrated flexibility in shape, size, tumor characteristics, tissue content, and ductal structure.
• FEM analysis showed the breast phantom achieved superior CTE in 2D and 3D compared to the block phantom.
• Significant differences in CTE and strain contrast were observed for deep/shallow tumors and when using 3D modeling versus 2D approximations.

Conclusions:

• The proposed 3D software breast phantom serves as a valuable intermediate tool for elastography simulation, outperforming traditional block phantoms.
• The phantom's superior CTE metrics and variability based on tumor characteristics enhance the study of elastography contrast.
• Utilizing 3D models without approximations, as with the breast phantom, leads to more accurate modulus estimation, crucial for 3D elastography systems.