What resolution is achieved with a Gaussian filter of 12mm or larger?

A Gaussian filter of 12mm or larger significantly impacts the quality of the resultant image produced in positron emission tomography (PET). When employing filters of this size, the primary effect is the smoothing of the image. At such resolutions, the filter effectively reduces the noise while averaging pixel values over a larger region, resulting in a very smooth appearance.

This smoothing process is particularly beneficial in enhancing the visual clarity of the image by diminishing the high-frequency noise, which can obscure important anatomical details. However, although this smoothing is advantageous for clearer visualization, it may also lead to a reduction in the definition of fine details, which is a critical aspect when assessing structures within a PET scan. As such, using a Gaussian filter of 12mm or larger prioritizes image aesthetics and clarity, producing an overall smoother appearance rather than improving the spatial resolution.