Quantitative image reconstruction for total-body PET imaging using the 2-meter long EXPLORER scanner.

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Biomedical Engineering

Background:

• The EXPLORER project is developing a 2-meter total-body PET scanner with unprecedented sensitivity.
• Current clinical PET scanners have limited fields of view, restricting whole-body imaging capabilities.
• Handling the vast data from EXPLORER's numerous lines-of-response (LORs) presents significant reconstruction challenges.

Purpose of the Study:

• Develop and evaluate a quantitative image reconstruction method for the EXPLORER scanner.
• Compare the EXPLORER's performance against existing whole-body PET scanners.
• Assess the impact of image reconstruction on image quality and noise reduction.

Main Methods:

• Implemented fully 3D, time-of-flight, list-mode image reconstruction using parallel computation.
• Applied an image domain resolution model to correct for parallax errors.
• Utilized SimSET Monte Carlo simulations and the XCAT 2.0 phantom for realistic 20-minute 18F-FDG whole-body scans.

Main Results:

• The EXPLORER scanner demonstrated superior image quality compared to a clinical scanner with a 22 cm axial FOV.
• A 6.9-fold reduction in noise standard deviation was achieved with the EXPLORER.
• The developed reconstruction method effectively addressed data handling and resolution recovery challenges.

Conclusions:

• The quantitative image reconstruction method is effective for the EXPLORER total-body PET scanner.
• EXPLORER offers significant advancements in sensitivity and image quality for whole-body PET imaging.
• This technology has the potential to revolutionize diagnostic capabilities in nuclear medicine.