Maximizing microcalcification detectability in low-dose dedicated cone-beam breast CT: parallel cascades-based...

Area of Science:

• Medical Imaging
• Radiological Physics

Background:

• Microcalcification clusters are early indicators of breast cancer.
• Dedicated cone-beam breast CT (CBCT) offers potential for improved breast imaging.
• Optimizing imaging parameters is crucial for maximizing diagnostic performance.

Purpose of the Study:

• To identify the optimal combination of X-ray spectrum and detector scintillator thickness for detecting microcalcification clusters in dedicated CBCT.
• To maximize the detectability index for microcalcifications using numerical observers.

Main Methods:

• A cascaded linear system analysis was performed in the spatial frequency domain.
• Numerical observers (prewhitening, nonprewhitening, nonprewhitening with eye filter) were used.
• The analysis evaluated thallium-doped cesium iodide scintillator thickness, X-ray tube voltage, and beam filtration.

Main Results:

• The optimal parameters for maximizing the detectability index were a scintillator thickness of 0.525 to 0.6 mm, 70 kV X-ray tube voltage, and 0.25 to 0.4 mm added copper filtration.
• This combination achieved the maximum detectability index at a mean glandular dose (MGD) of 4.5 mGy.

Conclusions:

• The study identified specific parameters to enhance microcalcification detection in CBCT.
• A harder X-ray beam, compared to current practices, may be beneficial for detecting microcalcifications.
• These findings support optimizing CBCT parameters for effective breast cancer screening at acceptable radiation doses.