Imaging Characteristics of ^I Between 3D and 2D on Siemens ECAT HR PET Scanner

124 I has a complex decay scheme with high gamma energy and low positron abundance. In this study, comparative performance measurements of 124 I were performed in terms of spatial resolution, sensitivity, and image quality. All measurements were performed using both 2D and 3D PET in both brain mode and whole body mode. The transverse and axial spatial resolutions at 1 cm were 5.56 and 6.07 mm for 124 I, and were 4.58 and 4.77 mm and for 18 F, respectively. Sensitivities were 0.5 kcps/MBq (2D) and 3.4 kcps/MBq (3D) for 124 I, and 1.8 kcps/MBq (2D) and 9.8 kcps/MBq (3D) for 18 F. The %contrast of 3D was higher than that of 2D in 124 I. For 124 I PET imaging, 3D acquisition with brain mode was highest achievable imaging acquisition mode with finer spatial resolution and higher contrast. This result will be useful for 124 I PET imaging.