Clinical information content at centimeter-scale voxel sizes in positronium lifetime imaging

Determine how much clinically viable information is contained in ortho-positronium lifetime images when reconstructed with centimeter-scale voxel sizes (for example, 2×2×2 cm or larger), in order to assess the diagnostic value of such coarse spatial binning.

Background

Published positronium lifetime imaging studies have often required long-lived radionuclides such as 22Na and employed very long scan times and/or large spatial binning, sometimes at the centimeter scale. These choices improve count statistics but raise concerns about loss of spatial detail.

In this work, the authors demonstrate voxel-wise imaging down to 4 mm using 124I on a long axial FOV PET/CT, yet they note that prior centimeter-scale binning may limit clinical utility. The unresolved question is how much diagnostic information remains when voxel sizes are in the multiple-centimeter range, as reported in earlier studies.