Prompt-gamma compensation in Rb-82 myocardial perfusion 3D PET/CT: Effect on clinical practice

Excerpt

PET imaging technology allows for absolute and relative myocardial blood flow analysis. In addition to the well-known positron emissions resulting in the production of annihilation radiation usually in the form of two 511 keV photons used for PET imaging, Rb-82 also emits 776 keV gamma rays with 13% abundance known as prompt gamma radiation.1 The effect on the images of these gamma emissions is different from those of random events or scatter; they produce a background signal which is incorrectly detected as coincidence events with the annihilation 511 keV photons. These unwelcomed coincidences lead to artifacts in both the appearance of the Rb-82 myocardial uptake as well as in image quantification if not corrected. Note that this is a unique characteristic of the Rb-82 radionuclide, and does not occur with any of the other radionuclides used for cardiac imaging such as N-13, O-15, or F-18. …