Single CT for attenuation correction of rest/stress cardiac SPECT perfusion imaging
Common practice is to use separate CT scans acquired during rest and stress for attenuation correction of SPECT myocardial perfusion imaging (MPI). We evaluated using a single CT scan to correct both rest and stress SPECT scans. Studies from 154 patients were reprocessed using one CT acquired at stress to correct both rest and stress scans (1CT) and compared to correction of each scan with its own CT (2CT). Two expert readers independently read the images and determined summed stress (SSS), rest (SRS), and difference (SDS) scores. The correlation in SRS between 2CT and 1CT was r ≥ 0.88. The concordance in SDS was ≥0.84 (kappa ≥ 0.62). The mean SDS difference between 2CT and 1CT for the averaged observer was not significantly different from zero (p > 0.31). 1CT images had a small but significant increase in SRS and an increase in SDS variability. However, the mean SDS difference was similar to the mean inter-observer SDS difference for the 2CT approach (−0.08 vs −0.23, p = 0.46) and had less uncertainty (1.02 vs 2.05, p < 0.001). Thus, the differences between 1CT and 2CT are unlikely to be clinically significant, and the 1CT approach is feasible for SPECT MPI.
KeywordsSPECT myocardial perfusion imaging attenuation correction radiation dose
Attenuation correction using a single CT acquired at stress for both rest and stress SPECT studies
Attenuation correction using a CT acquired at stress for the stress SPECT study and a CT acquired at rest for the rest SPECT study
Myocardial perfusion imaging
Summed difference score
Summed rest score
Summed stress score
This work was funded in part by a peer reviewed grant from the Ontario Research Fund (2008-13, RE-02-038).
RG Wells and TD Ruddy have received investigator-initiated grant support from GE Healthcare and Dr. Wells has received honoraria for speaking at GE Healthcare meetings.
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