Wide beam reconstruction for half-dose or half-time cardiac gated SPECT acquisitions: optimization of resources and reduction in radiation exposure

  • Claudio MarcassaEmail author
  • Riccardo Campini
  • Orazio Zoccarato
  • Paolo Calza
Original Article



A new iterative reconstruction algorithm (WBR™) has been recently proposed for cardiac single photon emission computed tomography (SPECT). The WBR™ technology is designed to reduce noise, improving lesion identification without affecting the image resolution, allowing SPECT studies with reduced count statistic. This allows for either half-time (HT) or half-dose (HD) cardiac SPECT, with image quality and quantitative data comparable to standard-time (ST) or standard-dose (SD) SPECT. Few data exist on the comparison between conventional filtered backprojection (FBP) and this new algorithm in a clinical setting. The aim of this study was to compare the performance of FBP and WBR™.


Phantoms studies were performed to compare spatial resolution and contrast recovery with FBP, ordered subset expectation maximization (OSEM) and WBR™. A group of 92 patients, with different cardiac pathology, scheduled for a stress-rest SPECT were studied: 52 patients (group A) were injected with a SD of tracer and underwent both ST and HT SPECT; 40 patients (group B) were injected with a half dose of tracer and underwent ST SPECT and immediately after an additional SPECT at double time/projection (DT), to compensate for the low count statistic. A 2-day 99mTc-sestamibi protocol was used in all patients. SD/ST and HD/DT SPECT were reconstructed with a conventional FBP; SD/HT and HD/ST SPECT were reconstructed with WBR™. The summed stress score (SSS) and summed rest score (SRS) were calculated; the left ventricular ejection fraction (LVEF) was automatically derived.


In group A (SD), no significant differences were observed between ST FBP SPECT and HT WBR™ in SSS (11.1 and 11.7, respectively) and SRS (9.4 and 10.3, respectively, NS). LVEF on rest acquisitions was also comparable (50% on ST SPECT and 49% on HT SPECT, NS); LVEF on post-stress studies in HT SPECT (46%) was lower than ST SPECT (50%), although not statistically significant. In group B (HD), SSS (6.2 in ST and 5.3 in DT) and SRS (4.0 in ST and 3.3 in DT) were also comparable. No differences were documented between ST and DT in rest (47 and 48%, respectively) and stress (48 and 50%, respectively) LVEF.


WBR™ performance and image quality were comparable to those of conventional FBP, allowing for either HT or HD studies. The former allows for an increased patient throughput and optimization of resources. The latter modalities would allow for a significant reduction in both patients’ and operators’ exposure. Further studies are needed to validate the clinical use of this method.


Myocardial perfusion scintigraphy SPECT Reconstruction algorithms Filtered backprojection Wide beam reconstruction 


Conflicts of interest



  1. 1.
    Borges-Neto S, Pagnanelli RA, Shaw LK, Honeycutt E, Shwartz SC, Adams GL, et al. Clinical results of a novel wide beam reconstruction method for shortening scan time of Tc-99m cardiac SPECT perfusion studies. J Nucl Cardiol 2007;14:555–65.CrossRefPubMedGoogle Scholar
  2. 2.
    Venero CV, Heller GV, Bateman TM, McGhie AI, Ahlberg AW, Courter D, et al. A multicenter evaluation of a new post-processing method with depth-dependent collimator resolution applied to full-time and half-time acquisitions without and with simultaneously acquired attenuation correction. J Nucl Cardiol 2009;16:714–25.CrossRefPubMedGoogle Scholar
  3. 3.
    DePuey EG, Bommireddipalli S, Clark J, Thompson L, Srour Y. Wide beam reconstruction “quarter-time” gated myocardial perfusion SPECT functional imaging: a comparison to “full-time” ordered subset expectation maximum. J Nucl Cardiol 2009;16:736–52.CrossRefPubMedGoogle Scholar
  4. 4.
    Marcassa C, Campini R, Zoccarato O, Calza P. Wide beam reconstruction for gated-SPECT: going toward optimization of resources and reduction in radiation exposure. Eur J Nucl Med Mol Imaging 2008;35(Suppl 2):S251.Google Scholar
  5. 5.
    DePuey G, Bommireddipalli S. Half-dose myocardial perfusion SPECT with wide beam reconstruction. Circulation 2009;120:S334CrossRefGoogle Scholar
  6. 6.
    Hesse B, Tägil K, Cuocolo A, Anagnostopoulos C, Bardiés M, Bax J, et al. EANM/ESC procedural guidelines for myocardial perfusion imaging in nuclear cardiology. Eur J Nucl Med Mol Imaging 2005;32(7):855–97.CrossRefPubMedGoogle Scholar
  7. 7.
    Germano G, Kiat H, Kavanagh PB, Moriel M, Mazzanti M, Su HT, et al. Automatic quantification of ejection fraction from gated myocardial perfusion SPECT. J Nucl Med 1995;36:2138–47.PubMedGoogle Scholar
  8. 8.
    Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurements. Lancet 1986;1(8476):307–10.PubMedGoogle Scholar
  9. 9.
    Zoccarato O, Campini R, Marcassa C, Calza P. Comparison between filtered back projection SPECT reconstruction and a new iterative reconstruction algorithm: a phantom study. Eur J Nucl Med Mol Imaging 2007;34(Suppl 2):S237.Google Scholar
  10. 10.
    Zoccarato O, Campini R, Marcassa C, Calza P. Comparison between filtered back projection SPECT reconstruction and a new iterative reconstruction algorithm: an anthropomorphic cardiac phantom study. Eur J Nucl Med Mol Imaging 2007;34(Suppl 2):S280.Google Scholar
  11. 11.
    Zoccarato O, Campini R, Marcassa C, Calza P. Performance of a new iterative reconstruction algorithm for cardiac short-time SPECT: preliminary results in an anthropomorphic cardiac phantom study. Comput Cardiol 2008;35:329–332.Google Scholar
  12. 12.
    Marcassa C, Bax JJ, Bengel F, Hesse B, Petersen L, Reyes E, et al. Clinical value, cost-effectiveness, and safety of myocardial perfusion scintigraphy: a position statement. Eur Heart J 2008;29:557–63.CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Claudio Marcassa
    • 1
    Email author
  • Riccardo Campini
    • 2
  • Orazio Zoccarato
    • 2
  • Paolo Calza
    • 2
  1. 1.Cardiology DepartmentS. Maugeri Fnd, IRCCS, Scientific Institute of Veruno (NO)VerunoItaly
  2. 2.Nuclear Medicine DepartmentS. Maugeri Fnd, IRCCS, Scientific Institute of Veruno (NO)VerunoItaly

Personalised recommendations