How to detect and avoid myocardial perfusion SPECT artifacts.

Although myocardial perfusion imaging with SPECT is an accurate and reliable diagnostic study, artifacts must be avoided, or detected and corrected, to minimize the rate of false-positive results. Common sources of artifacts are nonuniformity in gamma camera detectors, center of rotation errors, misaligned cameras on multidetector scanner systems, errors in image reconstruction, patient motion, radiotracer uptake in nontarget organs and attenuation. Some of these artifacts can be avoided by quality control of instrumentation and by imaging the patient in a prone rather than supine position to separate radiotracer activity from the target and nontarget organs and to reduce the effect of inferior wall attenuation. Other artifacts can be detected by careful image inspection and corrected by reprocessing. The best way to avoid artifacts is to pay very close attention to the technical factors of image acquisition and processing, and to be aware of attenuation factors.