Artifacts in iodine-131 renal images due to coincidence summing of technetium-99m photons.
Technetium-99m gamma camera images of kidneys produced with an iodine-131 energy window showed "ghosts" over and between the kidneys and between the kidneys and the bladder. The cause was coincidence summing at 281 keV due to a high 99mTc counting rate. In older model cameras careful peaking with a proper energy window reduces this effect; more recently developed cameras with pileup rejection circuits do not have this problem.
D006801:Humans; D007457:Iodine Radioisotopes; D007668:Kidney / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging / Q000295:instrumentation*; D013667:Technetium
D007457:Iodine Radioisotopes; D013667:Technetium