Attenuation correction in cardiac positron emission tomography and single-photon emission computed tomography

Quantitation in cardiac positron emission tomography (PET) and single-photon emission computed tomography (SPECT) depends on being able to correct for several physical factors that tend to distort the data. One of the most important of these corrections is the correction for attenuation. For PET, cardiac attenuation correction is a reality, although certain problems remain to be solved. For SPECT, recent developments in gamma camera hardware and reconstruction methods have finally made it possible to attempt attenuation correction in a clinical setting. This article reviews the methods available to perform attenuation correction in both PET and SPECT, with emphasis on the commonality between the problems encountered and solutions proposed for each modality.