Ordered subset expectation maximization and wide beam reconstruction “half-time” gated myocardial perfusion SPECT functional imaging: A comparison to “full-time” filtered backprojection
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Objectives: Compared to filtered back projection (FBP), OSEM with resolution recovery (OSEM-RR) and wide beam reconstruction (WBR)(UltraSPECT Ltd.), which resolve resolution and suppress noise simultaneously during reconstruction, have been shown to maintain/improve myocardial perfusion SPECT quality, even with low count density half-time acquisitions. We postulated that their characteristics would be advantageous for gated SPECT, where each frame is only 1/8th the count density of the summed perfusion images.
Methods: An 9 mCi rest/32 mCi (333/1184 MBq) stress Tc99m sestamibi protocol was used. 15-min FBP, and additional 7-min OSEM-RR and WBR post-stress 8-frame/cardiac cycle SPECT scans were acquired with 90°-angled dual-headed detectors equipped with high resolution collimators in 156 patients. In 82 patients (48F, 34M) (123–252 lbs) with perfusion defects gated image quality was graded visually: 1 (poor)-5 (excellent) Regional LV wall motion (WM) was scored: 0 (normal)- 4 (dyskinesis) in a total of 50 vascular territories with defects. Using Myometrix® software (GE Healthcare), post-stress EDV, ESV, and EF were calculated for each method. Additionally, for purposes of comparison, the FBP gated tomograms were processed with other commercially available packages, Emory Toolbox® and Cedars QGS®.
Results: Despite half-time acquisitions, compared to FBP, image quality increased marginally with OSEM-RR (P=.09) but very significantly with WBR (P=1.9×10−21). The WM score was greater only for WBR (P=4.8×10−8). Although quantitative parameters correlated well with those determined by FBP (all EF r’s>0.85; all volume r’s>0.93), EFs were significantly lower (P=.0001 for OSEM-RR, 3.4×10−14 for WBR), primarily due to a decrease in EDV with OSEM-RR (P=7.3×10−13) and an increase in ESV with WBR (P=9.2×10−5). However, inter-method differences in these parameters were of similar magnitude to differences encountered among the commercially available software methods.
Conclusions: Half-time OSEM-RR and particularly WBR improve gated SPECT diagnostic quality compared to full-time FBP due to increased resolution and reduced noise. However, these attributes, which affect endocardial edge detection, result in a systematic offset in EDV, ESV, and EF.
KeywordsSingle Photon Emission Compute Tomography Nuclear Cardiology Single Photon Emission Compute Tomography Image Filter Back Projection Gated Single Photon Emission Compute Tomography
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- 2.Thomas GS, Miyamoto MI, Morello AP, Majmundar H, Thomas JJ, Sampson CH, et al. Technetium 99m sestamibi myocardial perfusion imaging predicts clinical outcome in the community outpatient setting. The Nuclear Utility in the Community (NUC) Study. J Am Coll Cardiol 2004;43:213–23.PubMedCrossRefGoogle Scholar
- 3.DePuey EG, Taillefer R, Gadiraju R, Anstett F. A clinical evaluation of two resolution recovery methods for reduced scan time of gated MPI SPECT. Presented at the Annual Meeting of the American Society of Nuclear Cardiology, Montreal, September 8, 2006. Available from: URL: http://www.asnc.org/asnc2007/section_200.cfm.Google Scholar
- 9.Tsui BMW, Zhao XD, Frey EC, Gullberg GT. Characteristics of reconstructed point response in three-dimensional spatially variant detector response compensation in SPECT. In: Grangeat P, Amands J-L, editors. Three-dimensional image reconstruction in radiology and nuclear medicine. Norwell (MA): Kluwer Academic Publishers; 1996. p. 149–162.Google Scholar
- 10.Philipe P, Bruyant J. Analytic and iterative reconstruction algorithms in SPECT. J Nucl Med 2002;43:1343–58.Google Scholar
- 13.Farkash G, Kenig K, Grabnic M, Yuzefovich B, Sachs J, Bocher M. Volumetric quantitation of left ventricular perfusion and function from myocardial perfusion SPECT: Validation of a new algorithm [abstract]. J Nucl Cardiol 2006;13:S5.Google Scholar
- 14.Taillefer R, Primeau M, Costi P, Lambert R, Leville J, Latour Y. Technetium-99m-sestamibi myocardial perfusion imaging: Comparison between a short (8 minutes) and standard (21 minutes) data acquisition time in diagnosis of coronary artery disease [abstract]. J Nucl Med 1992;33:855.Google Scholar
- 16.Basso D, Passmore G, Holman M, Rogers W, Walters L. A clinical evaluation of a wide beam reconstruction method for shortening scan time of gated cardiac rest/stress SPECT [abstract]. J Nucl Med 2006;47:534P.Google Scholar
- 17.Pena H, Cantinho G, Shwartz SC, Pinhero M, Goncalves P, Godinho F. Has wide beam reconstruction technology for myocardial perfusion SPECT any impact on functional cardiac parameters [abstract]? Eur J Nucl Med Mol Imaging 2006;33(Suppl 2):S221.Google Scholar
- 18.Cantinho G, Pena H, Shwartz SC, Montiero J, Pereira L, Cerquiera D, et al. Wide beam reconstruction technology: Does it respect myocardial perfusion SPECT functional parameters [abstract]? J Nucl Cardiol 2007;14:S56.Google Scholar
- 20.Sharir T, Bacher-Stier C, Dhar S, Lewin HC, Miranda R, Friedman JD, et al. Identification of severe and extensive coronary artery disease by postexercise regional wall motion abnormalities in Tc-99m sestamibi gated single-photon emission computed tomography. Am J Cardiol 2000;86:1171–5.PubMedCrossRefGoogle Scholar