Axial slice width in 3D PET: characterization and potential improvement with axial interleaving

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Positron Emission Tomography (PET)

Background:

• Axial slice width in GE Advance PET scanner 3D acquisitions is known to be inferior to 2D.
• Understanding the causes of this degradation is crucial for optimizing image quality.

Purpose of the Study:

• Investigate the sources of reduced axial slice width in 3D PET acquisitions.
• Assess the potential for improving 3D axial slice width using axially interleaved data acquisition and reconstruction.

Main Methods:

• Measured axial slice width across three GE Advance PET scanner modes (high-sensitivity 2D, high-resolution 2D, 3D) with septa extended and retracted.
• Analyzed contributions of septa collimation, axial mispositioning, and 3D reconstruction effects.
• Estimated the impact of axially interleaved data on axial slice width.

Main Results:

• A significant degradation in axial slice width was observed for 3D compared to high-sensitivity 2D mode.
• Septa collimation predominantly affected 2D data near the center; axial mispositioning and 3D reconstruction effects became more significant at larger radial positions.
• Axial interleaving was estimated to improve axial slice width by 0.3-1.1 mm.

Conclusions:

• The study identified key factors contributing to reduced axial slice width in 3D PET.
• Axial interleaving presents a potential method for modest axial resolution improvement in GE Advance PET.
• Achieving this improvement necessitates a trade-off with increased image noise due to reconstruction filter adjustments.