To compare the image quality of PET images constructed using non-contrast PCD-CT image data to PET images constructed using conventional standard-of-care non-contrast EID-CT image data by performing a quantitative analysis of measurable image quality parameters.

To compare the subjective image quality of PET images constructed using non-contrast PCD-CT image data to PET images constructed using conventional standard-of-care non-contrast EID-CT image data by performing a qualitative analysis of diagnostic confidence as determined by board-certified radiologists/nuclear medicine physicians during image review.

A direct qualitative comparison of the subjective PET image quality will be performed.

Two blinded board-certified radiologists/nuclear medicine physicians will independently review PET images constructed using non-contrast PCD-CT data as well as PET images constructed using standard of care non-contrast EID-CT data in random order. Both raters will assess PET images subjectively regarding overall image quality using a five-point Likert scale. The rating will be defined as: (1) non-diagnostic - insufficient diagnostic confidence, (2) poor - low diagnostic confidence, (3) moderate - average diagnostic confidence; (4) good - high diagnostic confidence, and (5) excellent - full diagnostic confidence.

We expect that the subjective PET image quality will be improved by using non-contrast PCD-CT data for construction resulting in higher diagnostic confidence; demonstrating a case for the integration of PCD-CT into standard of care clinical PET-CT imaging in the future. There will be no direct benefit to study participants and the outcome will not be directly reported to the treatment team or patient and will not impact treatment or care received.