Frequent diagnostic errors in cardiac PET/CT due to misregistration of CT attenuation and emission PET images: a definitive analysis of causes, consequences, and corrections

Cardiac PET combined with CT is rapidly expanding despite ar-tifactual defects and false-positive results due to misregistration of PET and CT attenuation correction data—the frequency, cause, and correction of which remain undetermined.Methods: Two hundred fifty-nine consecutive patients underwent diagnos-tic rest–dipyridamole myocardial perfusion PET/CT using 82Rb, a 16-slice PET/CT scanner, helical CT attenuation correction with breathing and also at end-expiratory breath-hold, and averaged cine CT data during breathing. Misregistration on superimposed PET/CT fusion images was objectively measured in millimeters and correlated with associated quantitative size and severity of PET defects. Misregistration artifacts were defined as PET de-fects with corresponding misregistration on helical CT-PET fu-sion images that resolved after correct coregistration using a repeat CT scan, cine CT averaged attenuation during norma