Reduced count pediatric whole-body ¹⁸F-FDG PET imaging reconstruction with a Bayesian penalized likelihood algorithm

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiochemistry

Background:

• Advanced positron emission tomography (PET) reconstruction methods aim to optimize PET/CT protocols.
• Improvements include enhanced image quality, reduced administered activity, and shorter acquisition times.

Purpose of the Study:

• To assess the impact of reduced counts (simulating shorter acquisition times) on pediatric whole-body 18F-fluorodeoxyglucose (FDG) PET images reconstructed with BSREM.
• To compare BSREM reconstructions with reduced counts against OSEM reconstructed images.

Main Methods:

• Twenty children underwent whole-body 18F-FDG PET/CT using a 25-cm FOV digital PET/CT system at 90 s/bed with BSREM (β=700).
• Simulations included reduced counts at varying BSREM β levels (60, 50, 40, 30 s/bed) and one OSEM reconstruction (60 s/bed).
• Qualitative (Likert scores) and quantitative (SUV) analyses evaluated image quality and accuracy.

Main Results:

• No significant difference in qualitative measures was observed between BSREM reconstructions and the 90 s/bed standard (P>0.05).
• SUVmax for lesions was significantly lower only at 30 s/bed, β=1300 (P=0.001).
• BSREM at 40 s/bed, β=1000 was preferred over 60 s/bed TOF OSEM.

Conclusions:

• Reductions in acquisition time (>50%) are feasible for pediatric whole-body 18F-FDG PET/CT on a 25-cm FOV digital system.
• Diagnostic quality can be maintained using BSREM reconstruction, potentially decreasing administered activity or scan duration.
• BSREM offers a viable alternative to OSEM for accelerated PET/CT protocols in pediatric imaging.