A Preliminary Study On Artifacts Correction By CT-based Attenuation Methods In PET/CT Imaging

Objective To study the influence of different concentrations of meglumine solutions on PET/CT image quality as high-density materials and the influence with different CT protocols. Discuss PET/CT artifacts of the high-density materials and the causes of formation. So as to understand and read PET/CT image artifacts caused by high-density materials.Material and Methods Meglumine solutions with concentrations of 5%,10%,15%,20%and 40% were injected into five latex vessels, then were sealed into a cylindrical water phantom. GE Discovery LS PET/CT was used to scan the phantom with different CT tube voltages, followed by a conventional attenuation correction procedure. The SUV values were recorded and the comparisons were finally made among the images of different tube voltages and different concentrations of meglumine solutions, P < 0.05 had significant difference.Results There were artifacts in the areas filled with meglumine solutions that the concentrations were 15%, 20% and 40%.Standard Uptake Value(SUV) grew higher than the background with varying degrees. However, there were no apparent artifacts whenthe concentrations of the meglumine solutions was 5% or 10%.This would suggest that higher concentration of the meglumine solutions the artifacts of CT attenuation correction became more apparent. For the meglumine solutions with concentration of 5%,10%, 15%, 20% and 40%, the higher the CT tube voltages, the lower the SUV values grow, which has significant difference(P<0.05). And for tube voltages with 80 k V, 100 k V,120 k V and 140 k V, the higher concentration of the meglumine solutions, the higher the SUV values grow, which has significant difference(P<0.05).Conclusion The SUV of meglumine solutions PET/CT images with concentrations of more than 15% was higher than that of the background. There were artifacts on the images. When performing PET/CT scanning the higher CT tube voltages, the lower the SUV values of the meglumine solutions PET/CT images with CT attenuation correction grow, and there are the less artifacts. For the same tube voltage, the higher concentration of the meglumine solution, the higher the SUV value of the images with CT attenuation correction grows.