Over the years, there have been described at least four different methods to evaluate the PET image quality: image noise, noise equivalent count rate (NECR), NEMA NU-2 image quality phantom measurements and visual IQ.
Additionally, closer proximity to the detector should improve image resolution and count rate for both cameras.
These new detectors allow improved image resolution, higher count rate, as well as a reduced sensitivity to electromagnetic MR fields.
Furthermore, great advances have been made in PET hardware using APDs and SiPMs with improved image resolution, higher count rate, and reduced sensitivity to electromagnetic fields [87], introducing additional radiation dose reduction possibilities for PET/MRI.
Although the reconstructed images demonstrate quantitation issues at singles rates above 64.9 Mcps (Fig. 2), the fixed defects could be clearly observed in the same image regions regardless of count rate and activity present in the source (Fig. 3).
We have also studied the relation between the mean photon energy in a 10 arcsec/pixel image and the pixel count rate, arguing that at least two kinds of isobaric structures (a small isolated cloud and a larger feature) can be identified, both of which have interacted with a shock and both with their own thermal structure.
Spatial resolution, sensitivity, count rate and image quality were evaluated.
These include sensitivity, count rate performance, image quality, linearity and attenuation and scatter correction.
The dots appearing in corners are an experimental artifact corresponding to a ghost image of the lead map induced by an excessive count rate (Figure 7).
