Parametric positioning of a continuous crystal PET detector with depth of interaction decoding

Area of Science:

• Medical Physics
• Detector Technology
• Crystallography

Background:

• Accurate localization of scintillation events is crucial for advanced imaging applications.
• Continuous crystal detectors offer potential advantages but require precise positioning methods.
• Existing light distribution models may not optimally represent experimental data.

Purpose of the Study:

• To develop and validate a parametric positioning method for continuous crystal detectors.
• To compare the performance of the parametric model against Gaussian and Cauchy models.
• To assess the depth of interaction (DOI) resolution and intrinsic spatial resolution of the proposed method.

Main Methods:

• Testing three light distribution models: parametric, Gaussian, and Cauchy.
• Utilizing a continuous miniature crystal element (cMiCE) detector with an 8 mm LYSO crystal.
• Applying maximum-likelihood estimation (MLE) and weighted least-squares (WLS) fitting methods.
• Correlating light distribution parameters with depth of interaction (DOI) for 3D positioning.

Main Results:

• The parametric model demonstrated a superior fit to experimental data compared to Gaussian and Cauchy models.
• Achieved intrinsic spatial resolution of 1.06 mm (center) and 1.27 mm (corner) using the parametric model and MLE.
• Estimated DOI resolution (FWHM) of approximately 3.24 mm.
• The parametric method outperformed other models in both MLE and WLS fitting.

Conclusions:

• The parametric positioning method provides accurate 3D event localization in continuous crystal detectors.
• This technique achieves high spatial and DOI resolution with minimal detector calibration requirements.
• The parametric model offers a robust and sensitive approach for scintillation event detection.