Performance Characteristics of Long Axial Field-of-View PET Scanners with Axial Gaps

The introduction of long (>60 cm) axial field-of-view (LAFOV) PET systems has shown their potential for clinical and research applications. LAFOV scanners are expensive, so there is interest in designing systems with longer axial coverage while mitigating cost by introducing detector gaps. We used measurements on the PennPET Explorer (64-cm axial field-of-view (AFOV) prototype) and simulations of scanners up to 143-cm long to assess scanner performance with axial gaps introduced by varying the number of detector rows in each ring. Removing detectors reduces the total sensitivity and results in a nonuniform axial noise profile. Axial resolution shows small (