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Abstract

Purpose: Evaluation of 3D clinical whole-body FDG PET imaging using recent improvements in data correction and reconstruction methods.

Methods: Phantom studies following the NEMA NU 2-2000 draft were performed to evaluate count loss and accuracy of attenuation and scatter correction algorithms. Phantom results were used to estimate 3D vs. 2D efficiency. For patient studies, an established 2D imaging protocol (9 min emission, 3 min transmission acquisition per bed position, commencing 60 min after injection of 15 mCi FDG) was used. This was followed by a 3D acquisition of the same duration, commencing approximately 110 min later, so that 3D acquisition was performed with approximately 50% lower patient activity than 2D. Images were compared in terms of anatomic structural definition and visible artifacts.

The count loss study showed that in a dose range of 10-15 mCi, 3D produced an approximately two-fold increase in effective NEC compared to 2D. The phantom imaging study showed slightly improved target to background ratios for both hot and the cold “lesions” when using 3D imaging. In 5 patients studied so far, comparison of 2D and 3D studies demonstrated no systematic differences in image quality between the two methods.

Conclusion: 3D whole-body imaging with improved image reconstruction may permit a two-fold reduction in emission acquisition time or injected dose, without decrease in image quality compared to standard 2D imaging techniques.