Whole-body PET acceptance test in 2D and 3D using NEMA NU 2-2001 protocol

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Oncology

Background:

• Integrated Positron Emission Tomography/Computed Tomography (PET/CT) is crucial for cancer management, offering combined functional and morphological imaging.
• Bismuth germinate (BGO) crystal-based PET scanners are increasingly utilized for their imaging capabilities.

Purpose of the Study:

• To evaluate the performance of a newly installed Discovery ST PET/CT scanner.
• To assess its suitability for whole-body oncological imaging using standardized protocols.

Main Methods:

• Performance evaluation using the National Electrical Manufacturers Association (NEMA) NU 2-2001 protocol and standard phantoms.
• Measurements included spatial resolution, sensitivity, scatter fraction (SF), and counting rate performance in both 2D and 3D modes.
• System operated with a 375-650 keV energy window and 11.7 ns coincidence time window.

Main Results:

• Average transaxial and axial spatial resolution (FWHM) ranged from 0.491 cm to 0.691 cm.
• Sensitivity was 2.56-2.63 cps/kBq in 2D and 11.85-12.14 cps/kBq in 3D.
• Scatter fraction was 19.79% in 2D and 46.19% in 3D.
• Peak Noise Equivalent Counting Rate (NECR) was 89.41 kcps (2D) and 60 kcps (3D) with single random subtraction.

Conclusions:

• The Discovery ST PET/CT scanner met manufacturer specifications.
• The system exhibits excellent sensitivity and uniform spatial resolution, confirming its suitability for whole-body oncological studies.