A comparison of normalization effects on three whole-body cylindrical 3D PET systems

Normalization coefficients in three-dimensional positron emission tomograph y (3D PET) are affected by parameters such as camera geometry and the desig n and arrangement of the block detectors. In this work, normalization compo nents for three whole-body 3D-capable tomographs (the GE Advance, the Sieme ns/CTI962/HR+ and the Siemens/CTI 951R) are compared by means of a series o f scans using uniform cylindrical and rotating line sources. Where applicab le, the manufacturers' normalization methods are validated, and it is shown that these methods can be improved upon by using previously published norm alization protocols. Those architectural differences between the three tomo graphs that affect normalization are discussed with a view to drawing more general conclusions about the effect of machine architecture on normalizati on. The data presented suggest that uniformity of system response becomes e asier to achieve as the uniformity of crystal response within the detector block is improved.