Conceptual design and simulation study of an ROI-focused panel-PET scanner

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biophysics

Background:

• Conventional positron emission tomography (PET) scanners offer large fields-of-view (FOV) suitable for whole-body imaging.
• Often, imaging focuses on a specific region-of-interest (ROI), making large FOV systems potentially inefficient and costly.
• Smaller, ROI-focused PET systems could offer cost-effectiveness and portability for bedside applications.

Purpose of the Study:

• To investigate the feasibility of constructing an ROI-focused PET scanner using dual-headed panel-detectors.
• To develop and evaluate a novel image reconstruction method for ROI-focused PET.
• To assess the impact of time-of-flight (TOF) information on image quality and lesion detection performance.

Main Methods:

• Development of a novel windowed list-mode ordered subset expectation maximization (EM) algorithm for ROI image reconstruction.
• Utilizing dual-headed panel-detectors for focused data acquisition.
• Monte Carlo simulations to evaluate system performance, including lesion detection and the effect of TOF resolution.

Main Results:

• Demonstrated feasibility of detecting lesions as small as 1 cm in diameter with a timing resolution of 300 ps FWHM.
• Quantified the impact of TOF information, showing reduced distortions and artifacts with enhanced timing resolution.
• Observed improved detection of low-uptake lesions and faster lesion contrast recovery with superior TOF capabilities.

Conclusions:

• Dual-headed panel-detector based ROI-focused PET scanners are feasible for targeted imaging.
• The developed reconstruction method effectively utilizes TOF information for improved image quality and lesion detectability.
• Enhanced TOF resolution is critical for optimizing performance in lesion detection tasks, especially for subtle findings.