Sci-Fri AM: Imaging - 02: High resolution detectors for PET mammography

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biomedical Engineering

Background:

• Positron emission mammography (PEM) offers high specificity for malignant breast lesions.
• Improving sensitivity in dense breasts and reducing false positives are key goals for breast cancer screening.
• High scintillation detector efficiency is crucial for signal-to-noise ratio and minimizing patient dose in PEM.

Purpose of the Study:

• To develop a detector that increases photon detection efficiency by accepting wider incident angles.
• To implement depth-of-interaction (DOI) measurement to minimize parallax blurring in PEM.
• To design a detector minimizing photodetector count while enabling DOI measurement and crystal identification.

Main Methods:

• A prototype dual-ended readout block (DERB) detector was constructed using silicon photomultiplier (SiPM) arrays and LYSO scintillation crystals.
• The detector utilizes asymmetry of signals from dual photodetector arrays for DOI measurement.
• Anger Logic with light sharing was employed to identify interacting crystal elements.

Main Results:

• The DERB detector successfully identified interacting crystal elements.
• DOI was measured with approximately 5mm resolution in 2mm x 2mm x 20mm crystals.
• An average energy resolution of approximately 20% was achieved.

Conclusions:

• The DERB detector effectively reduces parallax effects in PEM systems without requiring additional photodetectors.
• This technology holds promise for enhancing PEM system performance.
• Further research is needed to optimize performance with high-efficiency photodetectors.