In this work, we compare two commercial positron emission tomography (PET) scanners installed at CIEMAT (Madrid, Spain): the ClearPET and the rPET-1. These systems
have significant geometrical differences, such as the axial field
of view (110 mm on ClearPET In this work, we compare two commercial positron emission tomography (PET) scanners installed at CIEMAT (Madrid, Spain): the ClearPET and the rPET-1. These systems
have significant geometrical differences, such as the axial field
of view (110 mm on ClearPET versus 45.6 mm on rPET-1), the
configuration of the detectors (whole ring on ClearPET versus
one pair of planar blocks on rPET-1) and the use of an axial
shift between ClearPET detector modules.We used an assessment procedure that fulfilled the recommendations of the National Electrical Manufacturers Association (NEMA) NU 4-2008 standard.
The methodology includes studies of spatial resolution, sensitivity, scatter fraction, count losses and image quality. Our experiments showed a central spatial resolution of 1.5 mm (transaxial), 3.2 mm (axial) for the ClearPET and 1.5 mm (transaxial), 1.6 mm (axial) for the rPET-1, with a small variation across the transverse
axis on both scanners (~1 mm). The absolute sensitivity at the centre of the field of view was 4.7% for the ClearPET and 1.0% for the rPET-1. The peak noise equivalent counting rate for the mouse-sized phantom was 73.4 kcps reached at 0.51 MBq/mL on the ClearPET and 29.2 kcps at 1.35 MBq/mL on the rPET-1. The recovery coefficients measured using the image quality phantom ranged from 0.11 to 0.89 on the ClearPET and from 0.14 to 0.81 on the rPET-1. The overall performance shows that both the ClearPET and the rPET-1 systems are very suitable for preclinical research and imaging of small animals[+][-]
