Potential of Hybrid PSF Correction to Suppress Gibbs Artifacts in PET Imaging

Le résumé fourni par la source

Point-spread-function (PSF) correction is used to compensate for the degradation of spatial resolution in positron emission tomography (PET) imaging. PSF correction improves image contrast and reduces image noise. However, it also causes Gibbs artifacts, which appear as signal overshoot along object edges, leading to decreased quantitative accuracy. Hybrid PSF correction, which combines sinogram-space and image-space PSF kernels, has been proposed as a potential solution to remove high frequency artifacts, but its effectiveness in suppressing Gibbs artifacts has not been sufficiently validated. This study aimed to evaluate the basic performance of hybrid PSF correction, to determine whether it can suppress Gibbs artifacts while maintaining good image quality. A brain tumor phantom filled with an18F solution was used, with the activity ratio between hot spheres and the background set to 4:1. PET data were acquired over 60 minutes, divided into five overlapping 30-minute frames, and reconstructed using hybrid PSF correction with varying image-space PSF kernel widths. The %contrast, coefficient of variation (CV), and magnitude of Gibbs artifacts (GA) were measured as physical indices. The GA decreased with narrower image-space PSF kernels. Although %contrast decreased and CV increased slightly as the kernel narrowed, overall image quality in the phantom images remained visually acceptable. These findings indicate that hybrid PSF correction can reduce Gibbs artifacts while preserving reasonable image quality. A trade-off exists between image quality and GA depending on kernel width.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.