Is there loss of data integrity as18 FDG metabolic imaging is performed with SPECT techniques compared with PET techniques?
Despite the inherently more limited spatial resolution of SPECT compared with PET and the lack of attenuation correction in these SPECT studies, the weight of the data would suggest that there is generally a very good correlation between regional activity data of18 FDG obtained with SPECT methodology compared with those obtained with PET and that data integrity is not greatly compromised. The degree of concordance in these studies is similar to that previously reported for thallium stress-redistribution-reinjection data and rest-redistribution thallium data. [22] The more limited spatial resolution of SPECT compared with PET would suggest, however, that in some instances, a truly infarcted segment may not be adequately resolved with SPECT. Indeed, Srinivasan and colleagues found that 27% of segments concordantly considered infarct by both PET and201 Tl demonstrated apparent metabolic activity by18 FDG-SPECT, raising questions as to possible loss of specificity by the metabolic SPECT ap
