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Simulation study of respiratory‐induced errors in cardiac positron emission tomography/computed tomography
Author(s) -
Fitzpatrick Gianna M.,
Wells R. Glenn
Publication year - 2006
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2211708
Subject(s) - cardiac pet , positron emission tomography , imaging phantom , correction for attenuation , nuclear medicine , positron emission , tomography , pet ct , preclinical imaging , medicine , radiology , in vivo , microbiology and biotechnology , biology
Heart disease is a leading killer in Canada and positron emission tomography (PET) provides clinicians with in vivo metabolic information for diagnosing heart disease. Transmission data are usually acquired withGe68 , although the advent of PET/CT scanners has made computed tomography (CT) an alternative option. The fast data acquisition of CT compared to PET may cause potential misregistration problems, leading to inaccurate attenuation correction (AC). Using Monte Carlo simulations and an anthropomorphic dynamic computer phantom, this study determines the magnitude and location of respiratory‐induced errors in radioactivity uptake measured in cardiac PET/CT. A homogeneous tracer distribution in the heart was considered. The AC was based on (1) a time‐averaged attenuation map, (2) CT maps from a single phase of the respiratory cycle, and (3) CT maps phase matched to the emission data. Circumferential profiles of the heart uptake were compared and differences of up to 24% were found between the single‐phase CT‐AC method and the true phantom values. Simulation results were supported by a PET/CT canine study which showed differences of up to 10% in the heart uptake in the lung‐heart boundary region when comparingGe68 ‐ to CT‐based AC with the CT map acquired at end inhalation.