Elsevier

Journal of Nuclear Cardiology

Volume 14, Issue 3, May–June 2007, Pages 314-323
Journal of Nuclear Cardiology

Original article
CT-based attenuation correction versus prone imaging to decrease equivocal interpretations of rest/stress Tc-99m tetrofosmin SPECT MPI

https://doi.org/10.1016/j.nuclcard.2007.02.005Get rights and content

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.

Section snippets

Patient Population

There were 334 consecutive patients over a period of 7 months who were referred for rest/stress MPI and who underwent stress imaging in the supine and prone position with a dual-head gamma camera equipped with an integrated x-ray transmission system (Infinia/Hawkeye; GE Healthcare). The population of patients was mixed regarding the likelihood of CAD, but there was a large cohort of patients with a low likelihood of CAD referred from the emergency department (Table 1). Patients (n = 10) with

Number of Equivocal Studies

The SSS of equivocal studies ranged from 1 to 8, with a mean (±SD) of 2.93 ± 1.71. The SSS of equivocal studies was 1, 2, or 3 in 68% of patients in both the exercise and adenosine group. The equivocal studies with an SSS of 8 involved 4 segments with a severity score of 2 for each segment and either the entire inferior wall and apex or the entire anterior wall and apex.

Figure 1 illustrates the number of studies classified as normal, equivocal, ischemia, and infarct when different sets of

Discussion

In this study the combination of stress supine SPECT imaging with and without AC decreased the number of equivocal interpretations to a greater extent than the combination of stress supine and stress prone imaging (both without AC), although the combination of all sets of images resulted in the lowest number of equivocal interpretations. This was true for both men and women, although both supine AC imaging and prone imaging were more helpful in men than in women. This was also true for both

Acknowledgment

The authors have indicated they have no financial conflicts of interest.

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