Background: The purpose of this study was to compare stress supine single photon emission computed tomography (SPECT) imaging with attenuation correction (AC) via computed tomography-based attenuation maps with stress prone SPECT imaging with regard to the rate of equivocal interpretation of rest/stress myocardial perfusion imaging.
Methods and results: Interpretations for 324 consecutive patients referred for rest/stress myocardial perfusion imaging were performed by use of the following sets of poststress SPECT images: supine with no AC (NC), supine NC/AC, supine NC/prone, and all images. The number of equivocal studies decreased with additional imaging: supine NC, 40%; supine NC/prone, 18%; supine NC/AC, 11%; and all images, 8%. The supine NC/AC sets of images reduced the number of defects to a greater extent than the supine NC/prone images for all patients (P = .01), men (P = .002), and women (P = .425). For the inferior (but not the anterior) wall, the percent decrease in defects with supine NC/AC images was lower as compared with supine NC/prone images.
Conclusion: Interpretation with all images resulted in the fewest equivocal studies. The supine NC/AC images reduced the number of equivocal studies to a greater extent than the supine NC/prone images. AC and prone imaging were more helpful in men than women and were more helpful to resolve inferior than anterior wall defects. Adding prone imaging to supine imaging without and with AC does not significantly alter the number of equivocal interpretations.