Abstract
Upward creep is reported to occur in exercise myocardial perfusion SPECT imaging due to a transient increasein the mean total pulmonary volume associated with exerise. We carried out the following study to clarify the artifact caused by upward creep. The frequency and characteristics of upward creep were evaluated in 225 patients who underwent exercise myocardial perfusion SPECT. Upward creep of 1 pixel or greater was noted in about 70% of the patients examined immediately after the end of the exercise protocol, and it could be classified into 4 patterns. When reproduction of these types of upward creep was attempted using a myocardial phantom, the artifact increased with the pixel shift caused by larger upward creep, and a characteristic artifact was appeared in each pattern of upward creep. Moreover, the intensity of the artifact varied with the radionuclide used for myocardial perfusion SPECT.
