Motion frozen (18)F-FDG cardiac PET

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Cardiovascular Imaging

Background:

• Positron Emission Tomography (PET) reconstruction using spatially variant 3D Point Spread Function (PSF) enhances image contrast and resolution.
• Cardiac Motion Frozen (CMF) processing mitigates cardiac motion artifacts in static PET images.
• Evaluating combined CMF and PSF reconstruction for high-resolution cardiac PET is crucial for diagnostic accuracy.

Purpose of the Study:

• To assess the efficacy of combined Cardiac Motion Frozen (CMF) and 3D Point Spread Function (PSF) reconstruction for high-resolution cardiac PET imaging.
• To compare the performance of CMF-PSF reconstruction against standard 2D-AWOSEM and PSF-only reconstruction methods.
• To evaluate improvements in myocardium-to-blood contrast, LV counts-to-defect contrast, contrast-to-noise ratio (CNR), and wall thickness.

Main Methods:

• Acquisition of static and 16-bin ECG-gated (18)F-FDG PET images from 20 patients using a Siemens Biograph-64 scanner.
• Application of CMF processing to gated images reconstructed with PSF.
• Comparative analysis of myocardium-to-blood contrast, LV counts-to-defect contrast, CNR, and wall thickness across different reconstruction methods: 2D-AWOSEM, PSF, ED-gated PSF, and CMF-PSF.

Main Results:

• CMF-PSF reconstruction resulted in significantly reduced measured wall thickness (13.8 ± 3.9 mm) compared to 2D-AWOSEM (18.9 ± 5.2 mm) and PSF (16.6 ± 4.5 mm) (P < .05).
• CMF-PSF demonstrated significantly higher myocardium-to-blood contrast (5.7 ± 2.7) and LV counts-to-defect contrast (10.0 ± 5.7) than 2D-AWOSEM and PSF (P < .05).
• Contrast-to-noise ratio (CNR) for CMF-PSF (26.3 ± 17.5) was comparable to PSF (29.1 ± 18.3) but significantly higher than ED-gated PSF (13.7 ± 8.8) (P < .05).

Conclusions:

• Combined CMF-PSF reconstruction significantly enhances myocardium-to-blood and LV counts-to-defect contrasts in cardiac PET.
• This combined approach maintains equivalent image noise levels compared to static summed 2D-AWOSEM and PSF reconstruction.
• CMF-PSF reconstruction offers improved image quality for high-resolution cardiac PET viability assessment.