Investigation of cold contrast recovery as a function of acquisition and reconstruction parameters for 2D cardiac PET

Cardiac PET imaging differs from oncology PET due to cold area detection and quantitation in the heart as compared to hot spot detection in whole-body FDG imaging for oncology. To assess reconstruction and acquisition settings for cold area imaging, a phantom containing six cold spheres, cold-rod sets and a uniform activity area was imaged on a dedicated PET-CT system using F-18 over a range of scanning conditions, activities and acquisition times. Count levels of 10, 20, 50, 200 and 650M counts were repeatedly acquired over a range of phantom total activity comparable to that which can be encountered in cardiac PET studies. Analysis included calculation of noise equivalent counts (NEC) and analysis of contrast versus background variability for each scan reconstructed with different OSEM iterations and filters and with FBP using various filters. For all count and NEC levels, higher and more consistent cold area contrast recovery was found with FBP reconstruction as compared to OSEM. In general, higher noise was found with FBP as compared to OSEM, but the difference diminished as the total counts increased into the range for cardiac PET. Therefore, FBP reconstruction methods should be considered in place of OSEM for cold feature imaging in cardiac PET